diff --git a/.github/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
new file mode 100644
index 000000000000..1632170c9d36
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,5 @@
+**If you are looking for support** please ask in **#synapse:matrix.org**
+(using a matrix.org account if necessary). We do not use GitHub issues for
+support.
+
+**If you want to report a security issue** please see https://matrix.org/security-disclosure-policy/
diff --git a/.github/ISSUE_TEMPLATE/BUG_REPORT.md b/.github/ISSUE_TEMPLATE/BUG_REPORT.md
index 9dd05bcba348..75c9b2c9feab 100644
--- a/.github/ISSUE_TEMPLATE/BUG_REPORT.md
+++ b/.github/ISSUE_TEMPLATE/BUG_REPORT.md
@@ -4,11 +4,13 @@ about: Create a report to help us improve
 
 ---
 
-<!--
+**THIS IS NOT A SUPPORT CHANNEL!**
+**IF YOU HAVE SUPPORT QUESTIONS ABOUT RUNNING OR CONFIGURING YOUR OWN HOME SERVER**,
+please ask in **#synapse:matrix.org** (using a matrix.org account if necessary)
 
-**IF YOU HAVE SUPPORT QUESTIONS ABOUT RUNNING OR CONFIGURING YOUR OWN HOME SERVER**:
-You will likely get better support more quickly if you ask in ** #synapse:matrix.org ** ;)
+<!--
 
+If you want to report a security issue, please see https://matrix.org/security-disclosure-policy/
 
 This is a bug report template. By following the instructions below and
 filling out the sections with your information, you will help the us to get all
diff --git a/CHANGES.md b/CHANGES.md
index 7dbe072fed11..225fced285a3 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,20 +1,5 @@
-Synapse 1.13.0rc2 (2020-05-14)
-==============================
-
-Bugfixes
---------
-
-- Fix a long-standing bug which could cause messages not to be sent over federation, when state events with state keys matching user IDs (such as custom user statuses) were received. ([\#7376](https://github.com/matrix-org/synapse/issues/7376))
-- Restore compatibility with non-compliant clients during the user interactive authentication process, fixing a problem introduced in v1.13.0rc1. ([\#7483](https://github.com/matrix-org/synapse/issues/7483))
-
-Internal Changes
-----------------
-
-- Fix linting errors in new version of Flake8. ([\#7470](https://github.com/matrix-org/synapse/issues/7470))
-
-
-Synapse 1.13.0rc1 (2020-05-11)
-==============================
+Synapse 1.13.0 (2020-05-19)
+===========================
 
 This release brings some potential changes necessary for certain
 configurations of Synapse:
@@ -34,6 +19,53 @@ configurations of Synapse:
 Please review [UPGRADE.rst](UPGRADE.rst) for more details on these changes
 and for general upgrade guidance.
 
+
+Notice of change to the default `git` branch for Synapse
+--------------------------------------------------------
+
+With the release of Synapse 1.13.0, the default `git` branch for Synapse has
+changed to `develop`, which is the development tip. This is more consistent with
+common practice and modern `git` usage.
+
+The `master` branch, which tracks the latest release, is still available. It is
+recommended that developers and distributors who have scripts which run builds
+using the default branch of Synapse should therefore consider pinning their
+scripts to `master`.
+
+
+Internal Changes
+----------------
+
+- Update the version of dh-virtualenv we use to build debs, and add focal to the list of target distributions. ([\#7526](https://github.com/matrix-org/synapse/issues/7526))
+
+
+Synapse 1.13.0rc3 (2020-05-18)
+==============================
+
+Bugfixes
+--------
+
+- Hash passwords as early as possible during registration. ([\#7523](https://github.com/matrix-org/synapse/issues/7523))
+
+
+Synapse 1.13.0rc2 (2020-05-14)
+==============================
+
+Bugfixes
+--------
+
+- Fix a long-standing bug which could cause messages not to be sent over federation, when state events with state keys matching user IDs (such as custom user statuses) were received. ([\#7376](https://github.com/matrix-org/synapse/issues/7376))
+- Restore compatibility with non-compliant clients during the user interactive authentication process, fixing a problem introduced in v1.13.0rc1. ([\#7483](https://github.com/matrix-org/synapse/issues/7483))
+
+Internal Changes
+----------------
+
+- Fix linting errors in new version of Flake8. ([\#7470](https://github.com/matrix-org/synapse/issues/7470))
+
+
+Synapse 1.13.0rc1 (2020-05-11)
+==============================
+
 Features
 --------
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 253a0ca648b0..062413e92531 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,62 +1,48 @@
-# Contributing code to Matrix
+# Contributing code to Synapse
 
-Everyone is welcome to contribute code to Matrix
-(https://github.com/matrix-org), provided that they are willing to license
-their contributions under the same license as the project itself. We follow a
-simple 'inbound=outbound' model for contributions: the act of submitting an
-'inbound' contribution means that the contributor agrees to license the code
-under the same terms as the project's overall 'outbound' license - in our
-case, this is almost always Apache Software License v2 (see [LICENSE](LICENSE)).
+Everyone is welcome to contribute code to [matrix.org
+projects](https://github.com/matrix-org), provided that they are willing to
+license their contributions under the same license as the project itself. We
+follow a simple 'inbound=outbound' model for contributions: the act of
+submitting an 'inbound' contribution means that the contributor agrees to
+license the code under the same terms as the project's overall 'outbound'
+license - in our case, this is almost always Apache Software License v2 (see
+[LICENSE](LICENSE)).
 
 ## How to contribute
 
-The preferred and easiest way to contribute changes to Matrix is to fork the
-relevant project on github, and then [create a pull request](
-https://help.github.com/articles/using-pull-requests/) to ask us to pull
-your changes into our repo.
+The preferred and easiest way to contribute changes is to fork the relevant
+project on github, and then [create a pull request](
+https://help.github.com/articles/using-pull-requests/) to ask us to pull your
+changes into our repo.
 
-**The single biggest thing you need to know is: please base your changes on
-the develop branch - *not* master.**
+Some other points to follow:
+ 
+ * Please base your changes on the `develop` branch.
+  
+ * Please follow the [code style requirements](#code-style).
 
-We use the master branch to track the most recent release, so that folks who
-blindly clone the repo and automatically check out master get something that
-works. Develop is the unstable branch where all the development actually
-happens: the workflow is that contributors should fork the develop branch to
-make a 'feature' branch for a particular contribution, and then make a pull
-request to merge this back into the matrix.org 'official' develop branch. We
-use github's pull request workflow to review the contribution, and either ask
-you to make any refinements needed or merge it and make them ourselves. The
-changes will then land on master when we next do a release.
+ * Please include a [changelog entry](#changelog) with each PR.
 
-We use [Buildkite](https://buildkite.com/matrix-dot-org/synapse) for continuous
-integration. If your change breaks the build, this will be shown in GitHub, so
-please keep an eye on the pull request for feedback.
+ * Please [sign off](#sign-off) your contribution.
 
-To run unit tests in a local development environment, you can use:
+ * Please keep an eye on the pull request for feedback from the [continuous
+   integration system](#continuous-integration-and-testing) and try to fix any
+   errors that come up.
 
-- ``tox -e py35`` (requires tox to be installed by ``pip install tox``)
-  for SQLite-backed Synapse on Python 3.5.
-- ``tox -e py36`` for SQLite-backed Synapse on Python 3.6.
-- ``tox -e py36-postgres`` for PostgreSQL-backed Synapse on Python 3.6
-  (requires a running local PostgreSQL with access to create databases).
-- ``./test_postgresql.sh`` for PostgreSQL-backed Synapse on Python 3.5
-  (requires Docker). Entirely self-contained, recommended if you don't want to
-  set up PostgreSQL yourself.
-
-Docker images are available for running the integration tests (SyTest) locally,
-see the [documentation in the SyTest repo](
-https://github.com/matrix-org/sytest/blob/develop/docker/README.md) for more
-information.
+ * If you need to [update your PR](#updating-your-pull-request), just add new
+   commits to your branch rather than rebasing.
 
 ## Code style
 
-All Matrix projects have a well-defined code-style - and sometimes we've even
-got as far as documenting it... For instance, synapse's code style doc lives
-[here](docs/code_style.md).
+Synapse's code style is documented [here](docs/code_style.md). Please follow
+it, including the conventions for the [sample configuration
+file](docs/code_style.md#configuration-file-format).
 
-To facilitate meeting these criteria you can run `scripts-dev/lint.sh`
-locally. Since this runs the tools listed in the above document, you'll need
-python 3.6 and to install each tool:
+Many of the conventions are enforced by scripts which are run as part of the
+[continuous integration system](#continuous-integration-and-testing). To help
+check if you have followed the code style, you can run `scripts-dev/lint.sh`
+locally. You'll need python 3.6 or later, and to install a number of tools:
 
 ```
 # Install the dependencies
@@ -67,9 +53,11 @@ pip install -U black flake8 flake8-comprehensions isort
 ```
 
 **Note that the script does not just test/check, but also reformats code, so you
-may wish to ensure any new code is committed first**. By default this script
-checks all files and can take some time; if you alter only certain files, you
-might wish to specify paths as arguments to reduce the run-time:
+may wish to ensure any new code is committed first**.
+
+By default, this script checks all files and can take some time; if you alter
+only certain files, you might wish to specify paths as arguments to reduce the
+run-time:
 
 ```
 ./scripts-dev/lint.sh path/to/file1.py path/to/file2.py path/to/folder
@@ -82,7 +70,6 @@ Please ensure your changes match the cosmetic style of the existing project,
 and **never** mix cosmetic and functional changes in the same commit, as it
 makes it horribly hard to review otherwise.
 
-
 ## Changelog
 
 All changes, even minor ones, need a corresponding changelog / newsfragment
@@ -98,24 +85,55 @@ in the format of `PRnumber.type`. The type can be one of the following:
 * `removal` (also used for deprecations)
 * `misc` (for internal-only changes)
 
-The content of the file is your changelog entry, which should be a short
-description of your change in the same style as the rest of our [changelog](
-https://github.com/matrix-org/synapse/blob/master/CHANGES.md). The file can
-contain Markdown formatting, and should end with a full stop (.) or an
-exclamation mark (!) for consistency.
+This file will become part of our [changelog](
+https://github.com/matrix-org/synapse/blob/master/CHANGES.md) at the next
+release, so the content of the file should be a short description of your
+change in the same style as the rest of the changelog. The file can contain Markdown
+formatting, and should end with a full stop (.) or an exclamation mark (!) for
+consistency.
 
 Adding credits to the changelog is encouraged, we value your
 contributions and would like to have you shouted out in the release notes!
 
 For example, a fix in PR #1234 would have its changelog entry in
-`changelog.d/1234.bugfix`, and contain content like "The security levels of
-Florbs are now validated when received over federation. Contributed by Jane
-Matrix.".
+`changelog.d/1234.bugfix`, and contain content like:
+
+> The security levels of Florbs are now validated when received
+> via the `/federation/florb` endpoint. Contributed by Jane Matrix.
+
+If there are multiple pull requests involved in a single bugfix/feature/etc,
+then the content for each `changelog.d` file should be the same. Towncrier will
+merge the matching files together into a single changelog entry when we come to
+release.
+
+### How do I know what to call the changelog file before I create the PR?
+
+Obviously, you don't know if you should call your newsfile
+`1234.bugfix` or `5678.bugfix` until you create the PR, which leads to a
+chicken-and-egg problem.
+
+There are two options for solving this:
+
+ 1. Open the PR without a changelog file, see what number you got, and *then*
+    add the changelog file to your branch (see [Updating your pull
+    request](#updating-your-pull-request)), or:
 
-## Debian changelog
+ 1. Look at the [list of all
+    issues/PRs](https://github.com/matrix-org/synapse/issues?q=), add one to the
+    highest number you see, and quickly open the PR before somebody else claims
+    your number.
+
+    [This
+    script](https://github.com/richvdh/scripts/blob/master/next_github_number.sh)
+    might be helpful if you find yourself doing this a lot.
+
+Sorry, we know it's a bit fiddly, but it's *really* helpful for us when we come
+to put together a release!
+
+### Debian changelog
 
 Changes which affect the debian packaging files (in `debian`) are an
-exception.
+exception to the rule that all changes require a `changelog.d` file.
 
 In this case, you will need to add an entry to the debian changelog for the
 next release. For this, run the following command:
@@ -200,19 +218,45 @@ Git allows you to add this signoff automatically when using the `-s`
 flag to `git commit`, which uses the name and email set in your
 `user.name` and `user.email` git configs.
 
-## Merge Strategy
+## Continuous integration and testing
+
+[Buildkite](https://buildkite.com/matrix-dot-org/synapse) will automatically
+run a series of checks and tests against any PR which is opened against the
+project; if your change breaks the build, this will be shown in GitHub, with
+links to the build results. If your build fails, please try to fix the errors
+and update your branch.
+
+To run unit tests in a local development environment, you can use:
+
+- ``tox -e py35`` (requires tox to be installed by ``pip install tox``)
+  for SQLite-backed Synapse on Python 3.5.
+- ``tox -e py36`` for SQLite-backed Synapse on Python 3.6.
+- ``tox -e py36-postgres`` for PostgreSQL-backed Synapse on Python 3.6
+  (requires a running local PostgreSQL with access to create databases).
+- ``./test_postgresql.sh`` for PostgreSQL-backed Synapse on Python 3.5
+  (requires Docker). Entirely self-contained, recommended if you don't want to
+  set up PostgreSQL yourself.
+
+Docker images are available for running the integration tests (SyTest) locally,
+see the [documentation in the SyTest repo](
+https://github.com/matrix-org/sytest/blob/develop/docker/README.md) for more
+information.
+
+## Updating your pull request
+
+If you decide to make changes to your pull request - perhaps to address issues
+raised in a review, or to fix problems highlighted by [continuous
+integration](#continuous-integration-and-testing) - just add new commits to your
+branch, and push to GitHub. The pull request will automatically be updated.
 
-We use the commit history of develop/master extensively to identify
-when regressions were introduced and what changes have been made.
+Please **avoid** rebasing your branch, especially once the PR has been
+reviewed: doing so makes it very difficult for a reviewer to see what has
+changed since a previous review.
 
-We aim to have a clean merge history, which means we normally squash-merge
-changes into develop. For small changes this means there is no need to rebase
-to clean up your PR before merging. Larger changes with an organised set of
-commits may be merged as-is, if the history is judged to be useful.
+## Notes for maintainers on merging PRs etc
 
-This use of squash-merging will mean PRs built on each other will be hard to 
-merge. We suggest avoiding these where possible, and if required, ensuring
-each PR has a tidy set of commits to ease merging.
+There are some notes for those with commit access to the project on how we
+manage git [here](docs/dev/git.md).
 
 ## Conclusion
 
diff --git a/README.rst b/README.rst
index 4db7d17e94f7..677689bc03b7 100644
--- a/README.rst
+++ b/README.rst
@@ -1,3 +1,11 @@
+================
+Synapse |shield|
+================
+
+.. |shield| image:: https://img.shields.io/matrix/synapse:matrix.org?label=support&logo=matrix
+  :alt: (get support on #synapse:matrix.org)
+  :target: https://matrix.to/#/#synapse:matrix.org
+
 .. contents::
 
 Introduction
@@ -77,6 +85,17 @@ Thanks for using Matrix!
 [1] End-to-end encryption is currently in beta: `blog post <https://matrix.org/blog/2016/11/21/matrixs-olm-end-to-end-encryption-security-assessment-released-and-implemented-cross-platform-on-riot-at-last>`_.
 
 
+Support
+=======
+
+For support installing or managing Synapse, please join |room|_ (from a matrix.org
+account if necessary) and ask questions there. We do not use GitHub issues for
+support requests, only for bug reports and feature requests.
+
+.. |room| replace:: ``#synapse:matrix.org``
+.. _room: https://matrix.to/#/#synapse:matrix.org
+
+
 Synapse Installation
 ====================
 
diff --git a/changelog.d/6391.feature b/changelog.d/6391.feature
new file mode 100644
index 000000000000..f123426e23ae
--- /dev/null
+++ b/changelog.d/6391.feature
@@ -0,0 +1 @@
+Synapse's cache factor can now be configured in `homeserver.yaml` by the `caches.global_factor` setting. Additionally, `caches.per_cache_factors` controls the cache factors for individual caches.
diff --git a/changelog.d/6590.misc b/changelog.d/6590.misc
new file mode 100644
index 000000000000..05a0156212f1
--- /dev/null
+++ b/changelog.d/6590.misc
@@ -0,0 +1 @@
+`synctl` now warns if it was unable to stop Synapse and will not attempt to start Synapse if nothing was stopped. Contributed by Romain Bouyé.
diff --git a/changelog.d/7256.feature b/changelog.d/7256.feature
new file mode 100644
index 000000000000..7ad767bf711e
--- /dev/null
+++ b/changelog.d/7256.feature
@@ -0,0 +1 @@
+Add OpenID Connect login/registration support. Contributed by Quentin Gliech, on behalf of [les Connecteurs](https://connecteu.rs).
diff --git a/changelog.d/7281.misc b/changelog.d/7281.misc
new file mode 100644
index 000000000000..86ad511e19de
--- /dev/null
+++ b/changelog.d/7281.misc
@@ -0,0 +1 @@
+Add MultiWriterIdGenerator to support multiple concurrent writers of streams.
diff --git a/changelog.d/7317.feature b/changelog.d/7317.feature
new file mode 100644
index 000000000000..23c063f28019
--- /dev/null
+++ b/changelog.d/7317.feature
@@ -0,0 +1 @@
+Add room details admin endpoint. Contributed by Awesome Technologies Innovationslabor GmbH.
diff --git a/changelog.d/7374.misc b/changelog.d/7374.misc
new file mode 100644
index 000000000000..676f285377f5
--- /dev/null
+++ b/changelog.d/7374.misc
@@ -0,0 +1 @@
+Move catchup of replication streams logic to worker.
diff --git a/changelog.d/7381.bugfix b/changelog.d/7381.bugfix
new file mode 100644
index 000000000000..e5f93571dcfa
--- /dev/null
+++ b/changelog.d/7381.bugfix
@@ -0,0 +1 @@
+Add an experimental room version which strictly adheres to the canonical JSON specification.
diff --git a/changelog.d/7382.misc b/changelog.d/7382.misc
new file mode 100644
index 000000000000..dbf7a530bea2
--- /dev/null
+++ b/changelog.d/7382.misc
@@ -0,0 +1 @@
+Add typing annotations in `synapse.federation`.
diff --git a/changelog.d/7384.bugfix b/changelog.d/7384.bugfix
new file mode 100644
index 000000000000..f49c600173b9
--- /dev/null
+++ b/changelog.d/7384.bugfix
@@ -0,0 +1 @@
+Fix a bug where event updates might not be sent over replication to worker processes after the stream falls behind.
diff --git a/changelog.d/7396.misc b/changelog.d/7396.misc
new file mode 100644
index 000000000000..290d2befc768
--- /dev/null
+++ b/changelog.d/7396.misc
@@ -0,0 +1 @@
+Convert the room handler to async/await.
diff --git a/changelog.d/7398.docker b/changelog.d/7398.docker
new file mode 100644
index 000000000000..dd2c6821c8c5
--- /dev/null
+++ b/changelog.d/7398.docker
@@ -0,0 +1 @@
+Update docker runtime image to Alpine v3.11. Contributed by @Starbix.
diff --git a/changelog.d/7435.feature b/changelog.d/7435.feature
new file mode 100644
index 000000000000..399291b13b64
--- /dev/null
+++ b/changelog.d/7435.feature
@@ -0,0 +1 @@
+Allow for using more than one spam checker module at once.
\ No newline at end of file
diff --git a/changelog.d/7436.misc b/changelog.d/7436.misc
new file mode 100644
index 000000000000..f7c451495097
--- /dev/null
+++ b/changelog.d/7436.misc
@@ -0,0 +1 @@
+Support any process writing to cache invalidation stream.
diff --git a/changelog.d/7440.misc b/changelog.d/7440.misc
new file mode 100644
index 000000000000..2505cdc66f9c
--- /dev/null
+++ b/changelog.d/7440.misc
@@ -0,0 +1 @@
+Refactor event persistence database functions in preparation for allowing them to be run on non-master processes.
diff --git a/changelog.d/7443.bugfix b/changelog.d/7443.bugfix
new file mode 100644
index 000000000000..1dddec59ed88
--- /dev/null
+++ b/changelog.d/7443.bugfix
@@ -0,0 +1 @@
+Allow expired user accounts to log out their device sessions.
\ No newline at end of file
diff --git a/changelog.d/7445.misc b/changelog.d/7445.misc
new file mode 100644
index 000000000000..801a6ca28479
--- /dev/null
+++ b/changelog.d/7445.misc
@@ -0,0 +1 @@
+Add type hints to the SAML handler.
diff --git a/changelog.d/7448.misc b/changelog.d/7448.misc
new file mode 100644
index 000000000000..2163cc9b971d
--- /dev/null
+++ b/changelog.d/7448.misc
@@ -0,0 +1 @@
+Remove storage method `get_hosts_in_room` that is no longer called anywhere.
\ No newline at end of file
diff --git a/changelog.d/7449.misc b/changelog.d/7449.misc
new file mode 100644
index 000000000000..e6ba94adaea1
--- /dev/null
+++ b/changelog.d/7449.misc
@@ -0,0 +1 @@
+Fix some typos in the notice_expiry templates.
diff --git a/changelog.d/7457.feature b/changelog.d/7457.feature
new file mode 100644
index 000000000000..7ad767bf711e
--- /dev/null
+++ b/changelog.d/7457.feature
@@ -0,0 +1 @@
+Add OpenID Connect login/registration support. Contributed by Quentin Gliech, on behalf of [les Connecteurs](https://connecteu.rs).
diff --git a/changelog.d/7458.doc b/changelog.d/7458.doc
new file mode 100644
index 000000000000..6fc2a243100c
--- /dev/null
+++ b/changelog.d/7458.doc
@@ -0,0 +1 @@
+Update information about mapping providers for SAML and OpenID.
diff --git a/changelog.d/7459.misc b/changelog.d/7459.misc
new file mode 100644
index 000000000000..7655f3412097
--- /dev/null
+++ b/changelog.d/7459.misc
@@ -0,0 +1 @@
+Convert the federation handler to async/await.
diff --git a/changelog.d/7460.misc b/changelog.d/7460.misc
new file mode 100644
index 000000000000..f71533fe1767
--- /dev/null
+++ b/changelog.d/7460.misc
@@ -0,0 +1 @@
+Convert the search handler to async/await.
diff --git a/changelog.d/7463.doc b/changelog.d/7463.doc
new file mode 100644
index 000000000000..85e63543035f
--- /dev/null
+++ b/changelog.d/7463.doc
@@ -0,0 +1 @@
+Add additional reverse proxy example for Caddy v2. Contributed by Jeff Peeler.
diff --git a/changelog.d/7465.bugfix b/changelog.d/7465.bugfix
new file mode 100644
index 000000000000..1cbe50caa5e4
--- /dev/null
+++ b/changelog.d/7465.bugfix
@@ -0,0 +1 @@
+Prevent rooms with 0 members or with invalid version strings from breaking group queries.
\ No newline at end of file
diff --git a/changelog.d/7470.misc b/changelog.d/7470.misc
new file mode 100644
index 000000000000..45e66ecf4812
--- /dev/null
+++ b/changelog.d/7470.misc
@@ -0,0 +1 @@
+Fix linting errors in new version of Flake8.
diff --git a/changelog.d/7473.bugfix b/changelog.d/7473.bugfix
new file mode 100644
index 000000000000..8c9510f5e32b
--- /dev/null
+++ b/changelog.d/7473.bugfix
@@ -0,0 +1 @@
+Workaround for an upstream Twisted bug that caused Synapse to become unresponsive after startup.
\ No newline at end of file
diff --git a/changelog.d/7475.misc b/changelog.d/7475.misc
new file mode 100644
index 000000000000..77759c3bd499
--- /dev/null
+++ b/changelog.d/7475.misc
@@ -0,0 +1 @@
+Have all instance correctly respond to REPLICATE command.
diff --git a/changelog.d/7477.doc b/changelog.d/7477.doc
new file mode 100644
index 000000000000..9a2d26111509
--- /dev/null
+++ b/changelog.d/7477.doc
@@ -0,0 +1 @@
+Fix copy-paste error in `ServerNoticesConfig` docstring. Contributed by @ptman.
\ No newline at end of file
diff --git a/changelog.d/7482.bugfix b/changelog.d/7482.bugfix
new file mode 100644
index 000000000000..018bf5cc896e
--- /dev/null
+++ b/changelog.d/7482.bugfix
@@ -0,0 +1 @@
+Fix Redis reconnection logic that can result in missed updates over replication if master reconnects to Redis without restarting.
diff --git a/changelog.d/7490.misc b/changelog.d/7490.misc
new file mode 100644
index 000000000000..7debf7871b47
--- /dev/null
+++ b/changelog.d/7490.misc
@@ -0,0 +1 @@
+Clean up replication unit tests.
diff --git a/changelog.d/7491.misc b/changelog.d/7491.misc
new file mode 100644
index 000000000000..50eb226db752
--- /dev/null
+++ b/changelog.d/7491.misc
@@ -0,0 +1 @@
+Move event stream handling out of slave store.
diff --git a/changelog.d/7492.misc b/changelog.d/7492.misc
new file mode 100644
index 000000000000..5ad31819d6c9
--- /dev/null
+++ b/changelog.d/7492.misc
@@ -0,0 +1 @@
+Allow censoring of events to happen on workers.
diff --git a/changelog.d/7493.misc b/changelog.d/7493.misc
new file mode 100644
index 000000000000..575c55a99b83
--- /dev/null
+++ b/changelog.d/7493.misc
@@ -0,0 +1 @@
+Move EventStream handling into default ReplicationDataHandler.
diff --git a/changelog.d/7495.feature b/changelog.d/7495.feature
new file mode 100644
index 000000000000..1150e714bd32
--- /dev/null
+++ b/changelog.d/7495.feature
@@ -0,0 +1 @@
+Add `instance_map` config and route replication calls.
diff --git a/changelog.d/7497.bugfix b/changelog.d/7497.bugfix
new file mode 100644
index 000000000000..3c7920cb1059
--- /dev/null
+++ b/changelog.d/7497.bugfix
@@ -0,0 +1 @@
+When sending `m.room.member` events, omit `displayname` and `avatar_url` if they aren't set instead of setting them to `null`. Contributed by Aaron Raimist.
diff --git a/changelog.d/7502.feature b/changelog.d/7502.feature
new file mode 100644
index 000000000000..059a05bfca1f
--- /dev/null
+++ b/changelog.d/7502.feature
@@ -0,0 +1 @@
+Add additional authentication checks for m.room.power_levels event per [MSC2209](https://github.com/matrix-org/matrix-doc/pull/2209).
diff --git a/changelog.d/7503.bugfix b/changelog.d/7503.bugfix
new file mode 100644
index 000000000000..d33d26dcbfc9
--- /dev/null
+++ b/changelog.d/7503.bugfix
@@ -0,0 +1 @@
+Fix incorrect `method` label on `synapse_http_matrixfederationclient_{requests,responses}` prometheus metrics.
diff --git a/changelog.d/7505.misc b/changelog.d/7505.misc
new file mode 100644
index 000000000000..26114a3744c0
--- /dev/null
+++ b/changelog.d/7505.misc
@@ -0,0 +1 @@
+Add type hints to `synapse.event_auth`.
diff --git a/changelog.d/7506.feature b/changelog.d/7506.feature
new file mode 100644
index 000000000000..1407c9168961
--- /dev/null
+++ b/changelog.d/7506.feature
@@ -0,0 +1 @@
+Implement room version 6 per [MSC2240](https://github.com/matrix-org/matrix-doc/pull/2240).
diff --git a/changelog.d/7507.misc b/changelog.d/7507.misc
new file mode 100644
index 000000000000..afc7a730b3be
--- /dev/null
+++ b/changelog.d/7507.misc
@@ -0,0 +1 @@
+Convert the room member handler to async/await.
diff --git a/changelog.d/7508.bugfix b/changelog.d/7508.bugfix
new file mode 100644
index 000000000000..c78e77c631da
--- /dev/null
+++ b/changelog.d/7508.bugfix
@@ -0,0 +1 @@
+Ignore incoming presence events from other homeservers if presence is disabled locally.
\ No newline at end of file
diff --git a/changelog.d/7511.bugfix b/changelog.d/7511.bugfix
new file mode 100644
index 000000000000..cf8bc69c6f17
--- /dev/null
+++ b/changelog.d/7511.bugfix
@@ -0,0 +1 @@
+Fix a long-standing bug that broke the update remote profile background process.
diff --git a/changelog.d/7513.misc b/changelog.d/7513.misc
new file mode 100644
index 000000000000..2ea7373e298b
--- /dev/null
+++ b/changelog.d/7513.misc
@@ -0,0 +1 @@
+Add type hints to room member handler.
diff --git a/changelog.d/7514.doc b/changelog.d/7514.doc
new file mode 100644
index 000000000000..981168c7e886
--- /dev/null
+++ b/changelog.d/7514.doc
@@ -0,0 +1 @@
+Improve the formatting of `reverse_proxy.md`.
diff --git a/changelog.d/7515.misc b/changelog.d/7515.misc
new file mode 100644
index 000000000000..48f3044f90c8
--- /dev/null
+++ b/changelog.d/7515.misc
@@ -0,0 +1 @@
+Allow `ReplicationRestResource` to be added to workers.
diff --git a/changelog.d/7516.misc b/changelog.d/7516.misc
new file mode 100644
index 000000000000..94b0fd49b2be
--- /dev/null
+++ b/changelog.d/7516.misc
@@ -0,0 +1 @@
+Add a worker store for search insertion, required for moving event persistence off master.
diff --git a/changelog.d/7518.misc b/changelog.d/7518.misc
new file mode 100644
index 000000000000..f6e143fe1c0d
--- /dev/null
+++ b/changelog.d/7518.misc
@@ -0,0 +1 @@
+Fix typing annotations in `tests.replication`.
diff --git a/changelog.d/7519.misc b/changelog.d/7519.misc
new file mode 100644
index 000000000000..c730b5e50799
--- /dev/null
+++ b/changelog.d/7519.misc
@@ -0,0 +1 @@
+Remove some redundant Python 2 support code.
diff --git a/changelog.d/7523.bugfix b/changelog.d/7523.bugfix
deleted file mode 100644
index 552dae39f08e..000000000000
--- a/changelog.d/7523.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Hash passwords as early as possible during registration.
diff --git a/changelog.d/7528.doc b/changelog.d/7528.doc
new file mode 100644
index 000000000000..6f2a783b50b0
--- /dev/null
+++ b/changelog.d/7528.doc
@@ -0,0 +1 @@
+Change the systemd worker service to check that the worker config file exists instead of silently failing. Contributed by David Vo.
diff --git a/changelog.d/7533.doc b/changelog.d/7533.doc
new file mode 100644
index 000000000000..e3c1df99faa6
--- /dev/null
+++ b/changelog.d/7533.doc
@@ -0,0 +1 @@
+Minor clarifications to the TURN docs.
diff --git a/changelog.d/7538.bugfix b/changelog.d/7538.bugfix
new file mode 100644
index 000000000000..4a614a9e61cc
--- /dev/null
+++ b/changelog.d/7538.bugfix
@@ -0,0 +1 @@
+ Hash passwords as early as possible during password reset.
diff --git a/changelog.d/7539.misc b/changelog.d/7539.misc
new file mode 100644
index 000000000000..93c030875a7e
--- /dev/null
+++ b/changelog.d/7539.misc
@@ -0,0 +1 @@
+Remove Ubuntu Cosmic and Disco from the list of distributions which we provide `.deb`s for, due to end-of-life.
diff --git a/changelog.d/7545.misc b/changelog.d/7545.misc
new file mode 100644
index 000000000000..177ec883e206
--- /dev/null
+++ b/changelog.d/7545.misc
@@ -0,0 +1 @@
+Make worker processes return a stubbed-out response to `GET /presence` requests.
diff --git a/changelog.d/7548.bugfix b/changelog.d/7548.bugfix
new file mode 100644
index 000000000000..1233b3b31a12
--- /dev/null
+++ b/changelog.d/7548.bugfix
@@ -0,0 +1 @@
+Fix bug where a local user leaving a room could fail under rare circumstances.
diff --git a/debian/build_virtualenv b/debian/build_virtualenv
index d892fd5c9d9a..4c9aabcac386 100755
--- a/debian/build_virtualenv
+++ b/debian/build_virtualenv
@@ -36,7 +36,6 @@ esac
 dh_virtualenv \
     --install-suffix "matrix-synapse" \
     --builtin-venv \
-    --setuptools \
     --python "$SNAKE" \
     --upgrade-pip \
     --preinstall="lxml" \
diff --git a/debian/changelog b/debian/changelog
index 8641571986e9..e7842d417416 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,16 +1,18 @@
-<<<<<<< HEAD
-matrix-synapse-py3 (1.12.3ubuntu1) UNRELEASED; urgency=medium
+matrix-synapse-py3 (1.13.0) stable; urgency=medium
 
+  [ Patrick Cloke ]
   * Add information about .well-known files to Debian installation scripts.
 
- -- Patrick Cloke <patrickc@matrix.org>  Mon, 06 Apr 2020 10:10:38 -0400
-=======
+  [ Synapse Packaging team ]
+  * New synapse release 1.13.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 19 May 2020 09:16:56 -0400
+
 matrix-synapse-py3 (1.12.4) stable; urgency=medium
 
   * New synapse release 1.12.4.
 
  -- Synapse Packaging team <packages@matrix.org>  Thu, 23 Apr 2020 10:58:14 -0400
->>>>>>> master
 
 matrix-synapse-py3 (1.12.3) stable; urgency=medium
 
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 93d61739ae81..9a3cf7b3f528 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -55,7 +55,7 @@ RUN pip install --prefix="/install" --no-warn-script-location \
 ### Stage 1: runtime
 ###
 
-FROM docker.io/python:${PYTHON_VERSION}-alpine3.10
+FROM docker.io/python:${PYTHON_VERSION}-alpine3.11
 
 # xmlsec is required for saml support
 RUN apk add --no-cache --virtual .runtime_deps \
diff --git a/docker/Dockerfile-dhvirtualenv b/docker/Dockerfile-dhvirtualenv
index ac9ebcfd88c2..579724685c2b 100644
--- a/docker/Dockerfile-dhvirtualenv
+++ b/docker/Dockerfile-dhvirtualenv
@@ -27,15 +27,16 @@ RUN env DEBIAN_FRONTEND=noninteractive apt-get install \
         wget
 
 # fetch and unpack the package
-RUN wget -q -O /dh-virtuenv-1.1.tar.gz https://github.com/spotify/dh-virtualenv/archive/1.1.tar.gz
-RUN tar xvf /dh-virtuenv-1.1.tar.gz
+RUN mkdir /dh-virtualenv
+RUN wget -q -O /dh-virtualenv.tar.gz https://github.com/matrix-org/dh-virtualenv/archive/matrixorg-20200519.tar.gz
+RUN tar -xv --strip-components=1 -C /dh-virtualenv -f /dh-virtualenv.tar.gz
 
 # install its build deps
-RUN cd dh-virtualenv-1.1/ \
-    && env DEBIAN_FRONTEND=noninteractive mk-build-deps -ri -t "apt-get -yqq --no-install-recommends"
+RUN cd /dh-virtualenv \
+    && env DEBIAN_FRONTEND=noninteractive mk-build-deps -ri -t "apt-get -y --no-install-recommends"
 
 # build it
-RUN cd dh-virtualenv-1.1 && dpkg-buildpackage -us -uc -b
+RUN cd /dh-virtualenv && dpkg-buildpackage -us -uc -b
 
 ###
 ### Stage 1
@@ -68,12 +69,12 @@ RUN apt-get update -qq -o Acquire::Languages=none \
         sqlite3 \
         libpq-dev
 
-COPY --from=builder /dh-virtualenv_1.1-1_all.deb /
+COPY --from=builder /dh-virtualenv_1.2~dev-1_all.deb /
 
 # install dhvirtualenv. Update the apt cache again first, in case we got a
 # cached cache from docker the first time.
 RUN apt-get update -qq -o Acquire::Languages=none \
-    && apt-get install -yq /dh-virtualenv_1.1-1_all.deb
+    && apt-get install -yq /dh-virtualenv_1.2~dev-1_all.deb
 
 WORKDIR /synapse/source
 ENTRYPOINT ["bash","/synapse/source/docker/build_debian.sh"]
diff --git a/docs/admin_api/rooms.md b/docs/admin_api/rooms.md
index 26fe8b8679a0..624e7745baa7 100644
--- a/docs/admin_api/rooms.md
+++ b/docs/admin_api/rooms.md
@@ -264,3 +264,57 @@ Response:
 
 Once the `next_token` parameter is no longer present, we know we've reached the
 end of the list.
+
+# DRAFT: Room Details API
+
+The Room Details admin API allows server admins to get all details of a room.
+
+This API is still a draft and details might change!
+
+The following fields are possible in the JSON response body:
+
+* `room_id` - The ID of the room.
+* `name` - The name of the room.
+* `canonical_alias` - The canonical (main) alias address of the room.
+* `joined_members` - How many users are currently in the room.
+* `joined_local_members` - How many local users are currently in the room.
+* `version` - The version of the room as a string.
+* `creator` - The `user_id` of the room creator.
+* `encryption` - Algorithm of end-to-end encryption of messages. Is `null` if encryption is not active.
+* `federatable` - Whether users on other servers can join this room.
+* `public` - Whether the room is visible in room directory.
+* `join_rules` - The type of rules used for users wishing to join this room. One of: ["public", "knock", "invite", "private"].
+* `guest_access` - Whether guests can join the room. One of: ["can_join", "forbidden"].
+* `history_visibility` - Who can see the room history. One of: ["invited", "joined", "shared", "world_readable"].
+* `state_events` - Total number of state_events of a room. Complexity of the room.
+
+## Usage
+
+A standard request:
+
+```
+GET /_synapse/admin/v1/rooms/<room_id>
+
+{}
+```
+
+Response:
+
+```
+{
+  "room_id": "!mscvqgqpHYjBGDxNym:matrix.org",
+  "name": "Music Theory",
+  "canonical_alias": "#musictheory:matrix.org",
+  "joined_members": 127
+  "joined_local_members": 2,
+  "version": "1",
+  "creator": "@foo:matrix.org",
+  "encryption": null,
+  "federatable": true,
+  "public": true,
+  "join_rules": "invite",
+  "guest_access": null,
+  "history_visibility": "shared",
+  "state_events": 93534
+}
+```
diff --git a/docs/admin_api/user_admin_api.rst b/docs/admin_api/user_admin_api.rst
index 859d7f99e7c8..776e71ec0439 100644
--- a/docs/admin_api/user_admin_api.rst
+++ b/docs/admin_api/user_admin_api.rst
@@ -33,21 +33,22 @@ with a body of:
 
 including an ``access_token`` of a server admin.
 
-The parameter ``displayname`` is optional and defaults to the value of
-``user_id``.
+Parameters:
 
-The parameter ``threepids`` is optional and allows setting the third-party IDs
-(email, msisdn) belonging to a user.
+- ``password``, optional. If provided, the user's password is updated and all
+  devices are logged out.
+  
+- ``displayname``, optional, defaults to the value of ``user_id``.
 
-The parameter ``avatar_url`` is optional. Must be a [MXC
-URI](https://matrix.org/docs/spec/client_server/r0.6.0#matrix-content-mxc-uris).
+- ``threepids``, optional, allows setting the third-party IDs (email, msisdn)
+  belonging to a user.
 
-The parameter ``admin`` is optional and defaults to ``false``.
+- ``avatar_url``, optional, must be a 
+  `MXC URI <https://matrix.org/docs/spec/client_server/r0.6.0#matrix-content-mxc-uris>`_.
 
-The parameter ``deactivated`` is optional and defaults to ``false``.
+- ``admin``, optional, defaults to ``false``.
 
-The parameter ``password`` is optional. If provided, the user's password is
-updated and all devices are logged out.
+- ``deactivated``, optional, defaults to ``false``.
 
 If the user already exists then optional parameters default to the current value.
 
diff --git a/docs/dev/git.md b/docs/dev/git.md
new file mode 100644
index 000000000000..b747ff20c982
--- /dev/null
+++ b/docs/dev/git.md
@@ -0,0 +1,148 @@
+Some notes on how we use git
+============================
+
+On keeping the commit history clean
+-----------------------------------
+
+In an ideal world, our git commit history would be a linear progression of
+commits each of which contains a single change building on what came
+before. Here, by way of an arbitrary example, is the top of `git log --graph
+b2dba0607`:
+
+<img src="git/clean.png" alt="clean git graph" width="500px">
+
+Note how the commit comment explains clearly what is changing and why. Also
+note the *absence* of merge commits, as well as the absence of commits called
+things like (to pick a few culprits):
+[“pep8”](https://github.com/matrix-org/synapse/commit/84691da6c), [“fix broken
+test”](https://github.com/matrix-org/synapse/commit/474810d9d),
+[“oops”](https://github.com/matrix-org/synapse/commit/c9d72e457),
+[“typo”](https://github.com/matrix-org/synapse/commit/836358823), or [“Who's
+the president?”](https://github.com/matrix-org/synapse/commit/707374d5d).
+
+There are a number of reasons why keeping a clean commit history is a good
+thing:
+
+ * From time to time, after a change lands, it turns out to be necessary to
+   revert it, or to backport it to a release branch. Those operations are
+   *much* easier when the change is contained in a single commit.
+
+ * Similarly, it's much easier to answer questions like “is the fix for
+   `/publicRooms` on the release branch?” if that change consists of a single
+   commit.
+
+ * Likewise: “what has changed on this branch in the last week?” is much
+   clearer without merges and “pep8” commits everywhere.
+
+ * Sometimes we need to figure out where a bug got introduced, or some
+   behaviour changed. One way of doing that is with `git bisect`: pick an
+   arbitrary commit between the known good point and the known bad point, and
+   see how the code behaves. However, that strategy fails if the commit you
+   chose is the middle of someone's epic branch in which they broke the world
+   before putting it back together again.
+
+One counterargument is that it is sometimes useful to see how a PR evolved as
+it went through review cycles. This is true, but that information is always
+available via the GitHub UI (or via the little-known [refs/pull
+namespace](https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/checking-out-pull-requests-locally)).
+
+
+Of course, in reality, things are more complicated than that. We have release
+branches as well as `develop` and `master`, and we deliberately merge changes
+between them. Bugs often slip through and have to be fixed later. That's all
+fine: this not a cast-iron rule which must be obeyed, but an ideal to aim
+towards.
+
+Merges, squashes, rebases: wtf?
+-------------------------------
+
+Ok, so that's what we'd like to achieve. How do we achieve it?
+
+The TL;DR is: when you come to merge a pull request, you *probably* want to
+“squash and merge”:
+
+![squash and merge](git/squash.png).
+
+(This applies whether you are merging your own PR, or that of another
+contributor.)
+
+“Squash and merge”<sup id="a1">[1](#f1)</sup> takes all of the changes in the
+PR, and bundles them into a single commit. GitHub gives you the opportunity to
+edit the commit message before you confirm, and normally you should do so,
+because the default will be useless (again: `* woops typo` is not a useful
+thing to keep in the historical record).
+
+The main problem with this approach comes when you have a series of pull
+requests which build on top of one another: as soon as you squash-merge the
+first PR, you'll end up with a stack of conflicts to resolve in all of the
+others. In general, it's best to avoid this situation in the first place by
+trying not to have multiple related PRs in flight at the same time. Still,
+sometimes that's not possible and doing a regular merge is the lesser evil.
+
+Another occasion in which a regular merge makes more sense is a PR where you've
+deliberately created a series of commits each of which makes sense in its own
+right. For example: [a PR which gradually propagates a refactoring operation
+through the codebase](https://github.com/matrix-org/synapse/pull/6837), or [a
+PR which is the culmination of several other
+PRs](https://github.com/matrix-org/synapse/pull/5987). In this case the ability
+to figure out when a particular change/bug was introduced could be very useful.
+
+Ultimately: **this is not a hard-and-fast-rule**. If in doubt, ask yourself “do
+each of the commits I am about to merge make sense in their own right”, but
+remember that we're just doing our best to balance “keeping the commit history
+clean” with other factors.
+
+Git branching model
+-------------------
+
+A [lot](https://nvie.com/posts/a-successful-git-branching-model/)
+[of](http://scottchacon.com/2011/08/31/github-flow.html)
+[words](https://www.endoflineblog.com/gitflow-considered-harmful) have been
+written in the past about git branching models (no really, [a
+lot](https://martinfowler.com/articles/branching-patterns.html)). I tend to
+think the whole thing is overblown. Fundamentally, it's not that
+complicated. Here's how we do it.
+
+Let's start with a picture:
+
+![branching model](git/branches.jpg)
+
+It looks complicated, but it's really not. There's one basic rule: *anyone* is
+free to merge from *any* more-stable branch to *any* less-stable branch at
+*any* time<sup id="a2">[2](#f2)</sup>. (The principle behind this is that if a
+change is good enough for the more-stable branch, then it's also good enough go
+put in a less-stable branch.)
+
+Meanwhile, merging (or squashing, as per the above) from a less-stable to a
+more-stable branch is a deliberate action in which you want to publish a change
+or a set of changes to (some subset of) the world: for example, this happens
+when a PR is landed, or as part of our release process.
+
+So, what counts as a more- or less-stable branch? A little reflection will show
+that our active branches are ordered thus, from more-stable to less-stable:
+
+ * `master` (tracks our last release).
+ * `release-vX.Y.Z` (the branch where we prepare the next release)<sup
+   id="a3">[3](#f3)</sup>.
+ * PR branches which are targeting the release.
+ * `develop` (our "mainline" branch containing our bleeding-edge).
+ * regular PR branches.
+
+The corollary is: if you have a bugfix that needs to land in both
+`release-vX.Y.Z` *and* `develop`, then you should base your PR on
+`release-vX.Y.Z`, get it merged there, and then merge from `release-vX.Y.Z` to
+`develop`. (If a fix lands in `develop` and we later need it in a
+release-branch, we can of course cherry-pick it, but landing it in the release
+branch first helps reduce the chance of annoying conflicts.)
+
+---
+
+<b id="f1">[1]</b>: “Squash and merge” is GitHub's term for this
+operation. Given that there is no merge involved, I'm not convinced it's the
+most intuitive name. [^](#a1)
+
+<b id="f2">[2]</b>: Well, anyone with commit access.[^](#a2)
+
+<b id="f3">[3]</b>: Very, very occasionally (I think this has happened once in
+the history of Synapse), we've had two releases in flight at once. Obviously,
+`release-v1.2.3` is more-stable than `release-v1.3.0`. [^](#a3)
diff --git a/docs/dev/git/branches.jpg b/docs/dev/git/branches.jpg
new file mode 100644
index 000000000000..715ecc8cd063
Binary files /dev/null and b/docs/dev/git/branches.jpg differ
diff --git a/docs/dev/git/clean.png b/docs/dev/git/clean.png
new file mode 100644
index 000000000000..3accd7ccefff
Binary files /dev/null and b/docs/dev/git/clean.png differ
diff --git a/docs/dev/git/squash.png b/docs/dev/git/squash.png
new file mode 100644
index 000000000000..234caca3e40b
Binary files /dev/null and b/docs/dev/git/squash.png differ
diff --git a/docs/dev/oidc.md b/docs/dev/oidc.md
new file mode 100644
index 000000000000..a90c5d24416c
--- /dev/null
+++ b/docs/dev/oidc.md
@@ -0,0 +1,175 @@
+# How to test OpenID Connect
+
+Any OpenID Connect Provider (OP) should work with Synapse, as long as it supports the authorization code flow.
+There are a few options for that:
+
+ - start a local OP. Synapse has been tested with [Hydra][hydra] and [Dex][dex-idp].
+   Note that for an OP to work, it should be served under a secure (HTTPS) origin.
+   A certificate signed with a self-signed, locally trusted CA should work. In that case, start Synapse with a `SSL_CERT_FILE` environment variable set to the path of the CA.
+ - use a publicly available OP. Synapse has been tested with [Google][google-idp].
+ - setup a SaaS OP, like [Auth0][auth0] and [Okta][okta]. Auth0 has a free tier which has been tested with Synapse.
+
+[google-idp]: https://developers.google.com/identity/protocols/OpenIDConnect#authenticatingtheuser
+[auth0]: https://auth0.com/
+[okta]: https://www.okta.com/
+[dex-idp]: https://github.com/dexidp/dex
+[hydra]: https://www.ory.sh/docs/hydra/
+
+
+## Sample configs
+
+Here are a few configs for providers that should work with Synapse.
+
+### [Dex][dex-idp]
+
+[Dex][dex-idp] is a simple, open-source, certified OpenID Connect Provider.
+Although it is designed to help building a full-blown provider, with some external database, it can be configured with static passwords in a config file.
+
+Follow the [Getting Started guide](https://github.com/dexidp/dex/blob/master/Documentation/getting-started.md) to install Dex.
+
+Edit `examples/config-dev.yaml` config file from the Dex repo to add a client:
+
+```yaml
+staticClients:
+- id: synapse
+  secret: secret
+  redirectURIs:
+  - '[synapse base url]/_synapse/oidc/callback'
+  name: 'Synapse'
+```
+
+Run with `dex serve examples/config-dex.yaml`
+
+Synapse config:
+
+```yaml
+oidc_config:
+   enabled: true
+   skip_verification: true # This is needed as Dex is served on an insecure endpoint
+   issuer: "http://127.0.0.1:5556/dex"
+   discover: true
+   client_id: "synapse"
+   client_secret: "secret"
+   scopes:
+     - openid
+     - profile
+   user_mapping_provider:
+     config:
+       localpart_template: '{{ user.name }}'
+       display_name_template: '{{ user.name|capitalize }}'
+```
+
+### [Auth0][auth0]
+
+1. Create a regular web application for Synapse
+2. Set the Allowed Callback URLs to `[synapse base url]/_synapse/oidc/callback`
+3. Add a rule to add the `preferred_username` claim.
+   <details>
+    <summary>Code sample</summary>
+
+    ```js
+    function addPersistenceAttribute(user, context, callback) {
+      user.user_metadata = user.user_metadata || {};
+      user.user_metadata.preferred_username = user.user_metadata.preferred_username || user.user_id;
+      context.idToken.preferred_username = user.user_metadata.preferred_username;
+
+      auth0.users.updateUserMetadata(user.user_id, user.user_metadata)
+        .then(function(){
+            callback(null, user, context);
+        })
+        .catch(function(err){
+            callback(err);
+        });
+    }
+    ```
+
+  </details>
+
+
+```yaml
+oidc_config:
+   enabled: true
+   issuer: "https://your-tier.eu.auth0.com/" # TO BE FILLED
+   discover: true
+   client_id: "your-client-id" # TO BE FILLED
+   client_secret: "your-client-secret" # TO BE FILLED
+   scopes:
+     - openid
+     - profile
+   user_mapping_provider:
+     config:
+       localpart_template: '{{ user.preferred_username }}'
+       display_name_template: '{{ user.name }}'
+```
+
+### GitHub
+
+GitHub is a bit special as it is not an OpenID Connect compliant provider, but just a regular OAuth2 provider.
+The `/user` API endpoint can be used to retrieve informations from the user.
+As the OIDC login mechanism needs an attribute to uniquely identify users and that endpoint does not return a `sub` property, an alternative `subject_claim` has to be set.
+
+1. Create a new OAuth application: https://github.com/settings/applications/new
+2. Set the callback URL to `[synapse base url]/_synapse/oidc/callback`
+
+```yaml
+oidc_config:
+   enabled: true
+   issuer: "https://github.com/"
+   discover: false
+   client_id: "your-client-id" # TO BE FILLED
+   client_secret: "your-client-secret" # TO BE FILLED
+   authorization_endpoint: "https://github.com/login/oauth/authorize"
+   token_endpoint: "https://github.com/login/oauth/access_token"
+   userinfo_endpoint: "https://api.github.com/user"
+   scopes:
+     - read:user
+   user_mapping_provider:
+     config:
+       subject_claim: 'id'
+       localpart_template: '{{ user.login }}'
+       display_name_template: '{{ user.name }}'
+```
+
+### Google
+
+1. Setup a project in the Google API Console
+2. Obtain the OAuth 2.0 credentials (see <https://developers.google.com/identity/protocols/oauth2/openid-connect>)
+3. Add this Authorized redirect URI: `[synapse base url]/_synapse/oidc/callback`
+
+```yaml
+oidc_config:
+   enabled: true
+   issuer: "https://accounts.google.com/"
+   discover: true
+   client_id: "your-client-id" # TO BE FILLED
+   client_secret: "your-client-secret" # TO BE FILLED
+   scopes:
+     - openid
+     - profile
+   user_mapping_provider:
+     config:
+       localpart_template: '{{ user.given_name|lower }}'
+       display_name_template: '{{ user.name }}'
+```
+
+### Twitch
+
+1. Setup a developer account on [Twitch](https://dev.twitch.tv/)
+2. Obtain the OAuth 2.0 credentials by [creating an app](https://dev.twitch.tv/console/apps/)
+3. Add this OAuth Redirect URL: `[synapse base url]/_synapse/oidc/callback`
+
+```yaml
+oidc_config:
+   enabled: true
+   issuer: "https://id.twitch.tv/oauth2/"
+   discover: true
+   client_id: "your-client-id" # TO BE FILLED
+   client_secret: "your-client-secret" # TO BE FILLED
+   client_auth_method: "client_secret_post"
+   scopes:
+     - openid
+   user_mapping_provider:
+     config:
+       localpart_template: '{{ user.preferred_username }}'
+       display_name_template: '{{ user.name }}'
+```
diff --git a/docs/reverse_proxy.md b/docs/reverse_proxy.md
index c7222f73b9fc..cbb8269568b3 100644
--- a/docs/reverse_proxy.md
+++ b/docs/reverse_proxy.md
@@ -9,7 +9,7 @@ of doing so is that it means that you can expose the default https port
 (443) to Matrix clients without needing to run Synapse with root
 privileges.
 
-> **NOTE**: Your reverse proxy must not `canonicalise` or `normalise`
+**NOTE**: Your reverse proxy must not `canonicalise` or `normalise`
 the requested URI in any way (for example, by decoding `%xx` escapes).
 Beware that Apache *will* canonicalise URIs unless you specifify
 `nocanon`.
@@ -18,7 +18,7 @@ When setting up a reverse proxy, remember that Matrix clients and other
 Matrix servers do not necessarily need to connect to your server via the
 same server name or port. Indeed, clients will use port 443 by default,
 whereas servers default to port 8448. Where these are different, we
-refer to the 'client port' and the \'federation port\'. See [the Matrix
+refer to the 'client port' and the 'federation port'. See [the Matrix
 specification](https://matrix.org/docs/spec/server_server/latest#resolving-server-names)
 for more details of the algorithm used for federation connections, and
 [delegate.md](<delegate.md>) for instructions on setting up delegation.
@@ -28,93 +28,113 @@ Let's assume that we expect clients to connect to our server at
 `https://example.com:8448`.  The following sections detail the configuration of
 the reverse proxy and the homeserver.
 
-## Webserver configuration examples
+## Reverse-proxy configuration examples
 
-> **NOTE**: You only need one of these.
+**NOTE**: You only need one of these.
 
 ### nginx
 
-        server {
-            listen 443 ssl;
-            listen [::]:443 ssl;
-            server_name matrix.example.com;
-
-            location /_matrix {
-                proxy_pass http://localhost:8008;
-                proxy_set_header X-Forwarded-For $remote_addr;
-                # Nginx by default only allows file uploads up to 1M in size
-                # Increase client_max_body_size to match max_upload_size defined in homeserver.yaml
-                client_max_body_size 10M;
-            }
-        }
-
-        server {
-            listen 8448 ssl default_server;
-            listen [::]:8448 ssl default_server;
-            server_name example.com;
-
-            location / {
-                proxy_pass http://localhost:8008;
-                proxy_set_header X-Forwarded-For $remote_addr;
-            }
-        }
-
-> **NOTE**: Do not add a `/` after the port in `proxy_pass`, otherwise nginx will
+```
+server {
+    listen 443 ssl;
+    listen [::]:443 ssl;
+    server_name matrix.example.com;
+
+    location /_matrix {
+        proxy_pass http://localhost:8008;
+        proxy_set_header X-Forwarded-For $remote_addr;
+        # Nginx by default only allows file uploads up to 1M in size
+        # Increase client_max_body_size to match max_upload_size defined in homeserver.yaml
+        client_max_body_size 10M;
+    }
+}
+
+server {
+    listen 8448 ssl default_server;
+    listen [::]:8448 ssl default_server;
+    server_name example.com;
+
+    location / {
+        proxy_pass http://localhost:8008;
+        proxy_set_header X-Forwarded-For $remote_addr;
+    }
+}
+```
+
+**NOTE**: Do not add a path after the port in `proxy_pass`, otherwise nginx will
 canonicalise/normalise the URI.
 
-### Caddy
+### Caddy 1
 
-        matrix.example.com {
-          proxy /_matrix http://localhost:8008 {
-            transparent
-          }
-        }
+```
+matrix.example.com {
+  proxy /_matrix http://localhost:8008 {
+    transparent
+  }
+}
 
-        example.com:8448 {
-          proxy / http://localhost:8008 {
-            transparent
-          }
-        }
+example.com:8448 {
+  proxy / http://localhost:8008 {
+    transparent
+  }
+}
+```
+
+### Caddy 2
+
+```
+matrix.example.com {
+  reverse_proxy /_matrix/* http://localhost:8008
+}
+
+example.com:8448 {
+  reverse_proxy http://localhost:8008
+}
+```
 
 ### Apache
 
-        <VirtualHost *:443>
-            SSLEngine on
-            ServerName matrix.example.com;
+```
+<VirtualHost *:443>
+    SSLEngine on
+    ServerName matrix.example.com;
 
-            AllowEncodedSlashes NoDecode
-            ProxyPass /_matrix http://127.0.0.1:8008/_matrix nocanon
-            ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
-        </VirtualHost>
+    AllowEncodedSlashes NoDecode
+    ProxyPass /_matrix http://127.0.0.1:8008/_matrix nocanon
+    ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
+</VirtualHost>
 
-        <VirtualHost *:8448>
-            SSLEngine on
-            ServerName example.com;
+<VirtualHost *:8448>
+    SSLEngine on
+    ServerName example.com;
 
-            AllowEncodedSlashes NoDecode
-            ProxyPass /_matrix http://127.0.0.1:8008/_matrix nocanon
-            ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
-        </VirtualHost>
+    AllowEncodedSlashes NoDecode
+    ProxyPass /_matrix http://127.0.0.1:8008/_matrix nocanon
+    ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
+</VirtualHost>
+```
 
-> **NOTE**: ensure the  `nocanon` options are included.
+**NOTE**: ensure the  `nocanon` options are included.
 
 ### HAProxy
 
-        frontend https
-          bind :::443 v4v6 ssl crt /etc/ssl/haproxy/ strict-sni alpn h2,http/1.1
+```
+frontend https
+  bind :::443 v4v6 ssl crt /etc/ssl/haproxy/ strict-sni alpn h2,http/1.1
 
-          # Matrix client traffic
-          acl matrix-host hdr(host) -i matrix.example.com
-          acl matrix-path path_beg /_matrix
+  # Matrix client traffic
+  acl matrix-host hdr(host) -i matrix.example.com
+  acl matrix-path path_beg /_matrix
 
-          use_backend matrix if matrix-host matrix-path
+  use_backend matrix if matrix-host matrix-path
 
-        frontend matrix-federation
-          bind :::8448 v4v6 ssl crt /etc/ssl/haproxy/synapse.pem alpn h2,http/1.1
-          default_backend matrix
+frontend matrix-federation
+  bind :::8448 v4v6 ssl crt /etc/ssl/haproxy/synapse.pem alpn h2,http/1.1
+  default_backend matrix
 
-        backend matrix
-          server matrix 127.0.0.1:8008
+backend matrix
+  server matrix 127.0.0.1:8008
+```
 
 ## Homeserver Configuration
 
diff --git a/docs/saml_mapping_providers.md b/docs/saml_mapping_providers.md
deleted file mode 100644
index 92f2380488c3..000000000000
--- a/docs/saml_mapping_providers.md
+++ /dev/null
@@ -1,77 +0,0 @@
-# SAML Mapping Providers
-
-A SAML mapping provider is a Python class (loaded via a Python module) that
-works out how to map attributes of a SAML response object to Matrix-specific
-user attributes. Details such as user ID localpart, displayname, and even avatar
-URLs are all things that can be mapped from talking to a SSO service.
-
-As an example, a SSO service may return the email address
-"john.smith@example.com" for a user, whereas Synapse will need to figure out how
-to turn that into a displayname when creating a Matrix user for this individual.
-It may choose `John Smith`, or `Smith, John [Example.com]` or any number of
-variations. As each Synapse configuration may want something different, this is
-where SAML mapping providers come into play.
-
-## Enabling Providers
-
-External mapping providers are provided to Synapse in the form of an external
-Python module. Retrieve this module from [PyPi](https://pypi.org) or elsewhere,
-then tell Synapse where to look for the handler class by editing the
-`saml2_config.user_mapping_provider.module` config option.
-
-`saml2_config.user_mapping_provider.config` allows you to provide custom
-configuration options to the module. Check with the module's documentation for
-what options it provides (if any). The options listed by default are for the
-user mapping provider built in to Synapse. If using a custom module, you should
-comment these options out and use those specified by the module instead.
-
-## Building a Custom Mapping Provider
-
-A custom mapping provider must specify the following methods:
-
-* `__init__(self, parsed_config)`
-   - Arguments:
-     - `parsed_config` - A configuration object that is the return value of the
-       `parse_config` method. You should set any configuration options needed by
-       the module here.
-* `saml_response_to_user_attributes(self, saml_response, failures)`
-    - Arguments:
-      - `saml_response` - A `saml2.response.AuthnResponse` object to extract user
-                          information from.
-      - `failures` - An `int` that represents the amount of times the returned
-                     mxid localpart mapping has failed.  This should be used
-                     to create a deduplicated mxid localpart which should be
-                     returned instead. For example, if this method returns
-                     `john.doe` as the value of `mxid_localpart` in the returned
-                     dict, and that is already taken on the homeserver, this
-                     method will be called again with the same parameters but
-                     with failures=1. The method should then return a different
-                     `mxid_localpart` value, such as `john.doe1`.
-    - This method must return a dictionary, which will then be used by Synapse
-      to build a new user. The following keys are allowed:
-       * `mxid_localpart` - Required. The mxid localpart of the new user.
-       * `displayname` - The displayname of the new user. If not provided, will default to
-                         the value of `mxid_localpart`.
-* `parse_config(config)`
-    - This method should have the `@staticmethod` decoration.
-    - Arguments:
-        - `config` - A `dict` representing the parsed content of the
-          `saml2_config.user_mapping_provider.config` homeserver config option.
-           Runs on homeserver startup. Providers should extract any option values
-           they need here.
-    - Whatever is returned will be passed back to the user mapping provider module's
-      `__init__` method during construction.
-* `get_saml_attributes(config)`
-    - This method should have the `@staticmethod` decoration.
-    - Arguments:
-        - `config` - A object resulting from a call to `parse_config`.
-    - Returns a tuple of two sets. The first set equates to the saml auth
-      response attributes that are required for the module to function, whereas
-      the second set consists of those attributes which can be used if available,
-      but are not necessary.
-
-## Synapse's Default Provider
-
-Synapse has a built-in SAML mapping provider if a custom provider isn't
-specified in the config. It is located at
-[`synapse.handlers.saml_handler.DefaultSamlMappingProvider`](../synapse/handlers/saml_handler.py).
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 98ead7dc0e6e..8a8415b9a290 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -603,6 +603,45 @@ acme:
 
 
 
+## Caching ##
+
+# Caching can be configured through the following options.
+#
+# A cache 'factor' is a multiplier that can be applied to each of
+# Synapse's caches in order to increase or decrease the maximum
+# number of entries that can be stored.
+
+# The number of events to cache in memory. Not affected by
+# caches.global_factor.
+#
+#event_cache_size: 10K
+
+caches:
+   # Controls the global cache factor, which is the default cache factor
+   # for all caches if a specific factor for that cache is not otherwise
+   # set.
+   #
+   # This can also be set by the "SYNAPSE_CACHE_FACTOR" environment
+   # variable. Setting by environment variable takes priority over
+   # setting through the config file.
+   #
+   # Defaults to 0.5, which will half the size of all caches.
+   #
+   #global_factor: 1.0
+
+   # A dictionary of cache name to cache factor for that individual
+   # cache. Overrides the global cache factor for a given cache.
+   #
+   # These can also be set through environment variables comprised
+   # of "SYNAPSE_CACHE_FACTOR_" + the name of the cache in capital
+   # letters and underscores. Setting by environment variable
+   # takes priority over setting through the config file.
+   # Ex. SYNAPSE_CACHE_FACTOR_GET_USERS_WHO_SHARE_ROOM_WITH_USER=2.0
+   #
+   per_cache_factors:
+     #get_users_who_share_room_with_user: 2.0
+
+
 ## Database ##
 
 # The 'database' setting defines the database that synapse uses to store all of
@@ -646,10 +685,6 @@ database:
   args:
     database: DATADIR/homeserver.db
 
-# Number of events to cache in memory.
-#
-#event_cache_size: 10K
-
 
 ## Logging ##
 
@@ -1470,6 +1505,94 @@ saml2_config:
   #template_dir: "res/templates"
 
 
+# Enable OpenID Connect for registration and login. Uses authlib.
+#
+oidc_config:
+    # enable OpenID Connect. Defaults to false.
+    #
+    #enabled: true
+
+    # use the OIDC discovery mechanism to discover endpoints. Defaults to true.
+    #
+    #discover: true
+
+    # the OIDC issuer. Used to validate tokens and discover the providers endpoints. Required.
+    #
+    #issuer: "https://accounts.example.com/"
+
+    # oauth2 client id to use. Required.
+    #
+    #client_id: "provided-by-your-issuer"
+
+    # oauth2 client secret to use. Required.
+    #
+    #client_secret: "provided-by-your-issuer"
+
+    # auth method to use when exchanging the token.
+    # Valid values are "client_secret_basic" (default), "client_secret_post" and "none".
+    #
+    #client_auth_method: "client_auth_basic"
+
+    # list of scopes to ask. This should include the "openid" scope. Defaults to ["openid"].
+    #
+    #scopes: ["openid"]
+
+    # the oauth2 authorization endpoint. Required if provider discovery is disabled.
+    #
+    #authorization_endpoint: "https://accounts.example.com/oauth2/auth"
+
+    # the oauth2 token endpoint. Required if provider discovery is disabled.
+    #
+    #token_endpoint: "https://accounts.example.com/oauth2/token"
+
+    # the OIDC userinfo endpoint. Required if discovery is disabled and the "openid" scope is not asked.
+    #
+    #userinfo_endpoint: "https://accounts.example.com/userinfo"
+
+    # URI where to fetch the JWKS. Required if discovery is disabled and the "openid" scope is used.
+    #
+    #jwks_uri: "https://accounts.example.com/.well-known/jwks.json"
+
+    # skip metadata verification. Defaults to false.
+    # Use this if you are connecting to a provider that is not OpenID Connect compliant.
+    # Avoid this in production.
+    #
+    #skip_verification: false
+
+
+    # An external module can be provided here as a custom solution to mapping
+    # attributes returned from a OIDC provider onto a matrix user.
+    #
+    user_mapping_provider:
+      # The custom module's class. Uncomment to use a custom module.
+      # Default is 'synapse.handlers.oidc_handler.JinjaOidcMappingProvider'.
+      #
+      #module: mapping_provider.OidcMappingProvider
+
+      # Custom configuration values for the module. Below options are intended
+      # for the built-in provider, they should be changed if using a custom
+      # module. This section will be passed as a Python dictionary to the
+      # module's `parse_config` method.
+      #
+      # Below is the config of the default mapping provider, based on Jinja2
+      # templates. Those templates are used to render user attributes, where the
+      # userinfo object is available through the `user` variable.
+      #
+      config:
+        # name of the claim containing a unique identifier for the user.
+        # Defaults to `sub`, which OpenID Connect compliant providers should provide.
+        #
+        #subject_claim: "sub"
+
+        # Jinja2 template for the localpart of the MXID
+        #
+        localpart_template: "{{ user.preferred_username }}"
+
+        # Jinja2 template for the display name to set on first login. Optional.
+        #
+        #display_name_template: "{{ user.given_name }} {{ user.last_name }}"
+
+
 
 # Enable CAS for registration and login.
 #
@@ -1554,6 +1677,13 @@ sso:
     #
     #   This template has no additional variables.
     #
+    # * HTML page to display to users if something goes wrong during the
+    #   OpenID Connect authentication process: 'sso_error.html'.
+    #
+    #   When rendering, this template is given two variables:
+    #     * error: the technical name of the error
+    #     * error_description: a human-readable message for the error
+    #
     # You can see the default templates at:
     # https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
     #
@@ -1772,10 +1902,17 @@ password_providers:
 #  include_content: true
 
 
-#spam_checker:
-#  module: "my_custom_project.SuperSpamChecker"
-#  config:
-#    example_option: 'things'
+# Spam checkers are third-party modules that can block specific actions
+# of local users, such as creating rooms and registering undesirable
+# usernames, as well as remote users by redacting incoming events.
+#
+spam_checker:
+   #- module: "my_custom_project.SuperSpamChecker"
+   #  config:
+   #    example_option: 'things'
+   #- module: "some_other_project.BadEventStopper"
+   #  config:
+   #    example_stop_events_from: ['@bad:example.com']
 
 
 # Uncomment to allow non-server-admin users to create groups on this server
diff --git a/docs/spam_checker.md b/docs/spam_checker.md
index 5b5f5000b76f..eb10e115f98f 100644
--- a/docs/spam_checker.md
+++ b/docs/spam_checker.md
@@ -64,10 +64,12 @@ class ExampleSpamChecker:
 Modify the `spam_checker` section of your `homeserver.yaml` in the following
 manner:
 
-`module` should point to the fully qualified Python class that implements your
-custom logic, e.g. `my_module.ExampleSpamChecker`.
+Create a list entry with the keys `module` and `config`.
 
-`config` is a dictionary that gets passed to the spam checker class.
+* `module` should point to the fully qualified Python class that implements your
+  custom logic, e.g. `my_module.ExampleSpamChecker`.
+
+* `config` is a dictionary that gets passed to the spam checker class.
 
 ### Example
 
@@ -75,12 +77,15 @@ This section might look like:
 
 ```yaml
 spam_checker:
-  module: my_module.ExampleSpamChecker
-  config:
-    # Enable or disable a specific option in ExampleSpamChecker.
-    my_custom_option: true
+  - module: my_module.ExampleSpamChecker
+    config:
+      # Enable or disable a specific option in ExampleSpamChecker.
+      my_custom_option: true
 ```
 
+More spam checkers can be added in tandem by appending more items to the list. An
+action is blocked when at least one of the configured spam checkers flags it.
+
 ## Examples
 
 The [Mjolnir](https://github.com/matrix-org/mjolnir) project is a full fledged
diff --git a/docs/sso_mapping_providers.md b/docs/sso_mapping_providers.md
new file mode 100644
index 000000000000..4cd3a568f22b
--- /dev/null
+++ b/docs/sso_mapping_providers.md
@@ -0,0 +1,146 @@
+# SSO Mapping Providers
+
+A mapping provider is a Python class (loaded via a Python module) that
+works out how to map attributes of a SSO response to Matrix-specific
+user attributes. Details such as user ID localpart, displayname, and even avatar
+URLs are all things that can be mapped from talking to a SSO service.
+
+As an example, a SSO service may return the email address
+"john.smith@example.com" for a user, whereas Synapse will need to figure out how
+to turn that into a displayname when creating a Matrix user for this individual.
+It may choose `John Smith`, or `Smith, John [Example.com]` or any number of
+variations. As each Synapse configuration may want something different, this is
+where SAML mapping providers come into play.
+
+SSO mapping providers are currently supported for OpenID and SAML SSO
+configurations. Please see the details below for how to implement your own.
+
+External mapping providers are provided to Synapse in the form of an external
+Python module. You can retrieve this module from [PyPi](https://pypi.org) or elsewhere,
+but it must be importable via Synapse (e.g. it must be in the same virtualenv
+as Synapse). The Synapse config is then modified to point to the mapping provider
+(and optionally provide additional configuration for it).
+
+## OpenID Mapping Providers
+
+The OpenID mapping provider can be customized by editing the
+`oidc_config.user_mapping_provider.module` config option.
+
+`oidc_config.user_mapping_provider.config` allows you to provide custom
+configuration options to the module. Check with the module's documentation for
+what options it provides (if any). The options listed by default are for the
+user mapping provider built in to Synapse. If using a custom module, you should
+comment these options out and use those specified by the module instead.
+
+### Building a Custom OpenID Mapping Provider
+
+A custom mapping provider must specify the following methods:
+
+* `__init__(self, parsed_config)`
+   - Arguments:
+     - `parsed_config` - A configuration object that is the return value of the
+       `parse_config` method. You should set any configuration options needed by
+       the module here.
+* `parse_config(config)`
+    - This method should have the `@staticmethod` decoration.
+    - Arguments:
+        - `config` - A `dict` representing the parsed content of the
+          `oidc_config.user_mapping_provider.config` homeserver config option.
+           Runs on homeserver startup. Providers should extract and validate
+           any option values they need here.
+    - Whatever is returned will be passed back to the user mapping provider module's
+      `__init__` method during construction.
+* `get_remote_user_id(self, userinfo)`
+    - Arguments:
+      - `userinfo` - A `authlib.oidc.core.claims.UserInfo` object to extract user
+                     information from.
+    - This method must return a string, which is the unique identifier for the
+      user. Commonly the ``sub`` claim of the response.
+* `map_user_attributes(self, userinfo, token)`
+    - This method should be async.
+    - Arguments:
+      - `userinfo` - A `authlib.oidc.core.claims.UserInfo` object to extract user
+                     information from.
+      - `token` - A dictionary which includes information necessary to make
+                  further requests to the OpenID provider.
+    - Returns a dictionary with two keys:
+      - localpart: A required string, used to generate the Matrix ID.
+      - displayname: An optional string, the display name for the user.
+
+### Default OpenID Mapping Provider
+
+Synapse has a built-in OpenID mapping provider if a custom provider isn't
+specified in the config. It is located at
+[`synapse.handlers.oidc_handler.JinjaOidcMappingProvider`](../synapse/handlers/oidc_handler.py).
+
+## SAML Mapping Providers
+
+The SAML mapping provider can be customized by editing the
+`saml2_config.user_mapping_provider.module` config option.
+
+`saml2_config.user_mapping_provider.config` allows you to provide custom
+configuration options to the module. Check with the module's documentation for
+what options it provides (if any). The options listed by default are for the
+user mapping provider built in to Synapse. If using a custom module, you should
+comment these options out and use those specified by the module instead.
+
+### Building a Custom SAML Mapping Provider
+
+A custom mapping provider must specify the following methods:
+
+* `__init__(self, parsed_config)`
+   - Arguments:
+     - `parsed_config` - A configuration object that is the return value of the
+       `parse_config` method. You should set any configuration options needed by
+       the module here.
+* `parse_config(config)`
+    - This method should have the `@staticmethod` decoration.
+    - Arguments:
+        - `config` - A `dict` representing the parsed content of the
+          `saml_config.user_mapping_provider.config` homeserver config option.
+           Runs on homeserver startup. Providers should extract and validate
+           any option values they need here.
+    - Whatever is returned will be passed back to the user mapping provider module's
+      `__init__` method during construction.
+* `get_saml_attributes(config)`
+    - This method should have the `@staticmethod` decoration.
+    - Arguments:
+        - `config` - A object resulting from a call to `parse_config`.
+    - Returns a tuple of two sets. The first set equates to the SAML auth
+      response attributes that are required for the module to function, whereas
+      the second set consists of those attributes which can be used if available,
+      but are not necessary.
+* `get_remote_user_id(self, saml_response, client_redirect_url)`
+    - Arguments:
+      - `saml_response` - A `saml2.response.AuthnResponse` object to extract user
+                          information from.
+      - `client_redirect_url` - A string, the URL that the client will be
+                                redirected to.
+    - This method must return a string, which is the unique identifier for the
+      user. Commonly the ``uid`` claim of the response.
+* `saml_response_to_user_attributes(self, saml_response, failures, client_redirect_url)`
+    - Arguments:
+      - `saml_response` - A `saml2.response.AuthnResponse` object to extract user
+                          information from.
+      - `failures` - An `int` that represents the amount of times the returned
+                     mxid localpart mapping has failed.  This should be used
+                     to create a deduplicated mxid localpart which should be
+                     returned instead. For example, if this method returns
+                     `john.doe` as the value of `mxid_localpart` in the returned
+                     dict, and that is already taken on the homeserver, this
+                     method will be called again with the same parameters but
+                     with failures=1. The method should then return a different
+                     `mxid_localpart` value, such as `john.doe1`.
+      - `client_redirect_url` - A string, the URL that the client will be
+                                redirected to.
+    - This method must return a dictionary, which will then be used by Synapse
+      to build a new user. The following keys are allowed:
+       * `mxid_localpart` - Required. The mxid localpart of the new user.
+       * `displayname` - The displayname of the new user. If not provided, will default to
+                         the value of `mxid_localpart`.
+
+### Default SAML Mapping Provider
+
+Synapse has a built-in SAML mapping provider if a custom provider isn't
+specified in the config. It is located at
+[`synapse.handlers.saml_handler.DefaultSamlMappingProvider`](../synapse/handlers/saml_handler.py).
diff --git a/docs/systemd-with-workers/system/matrix-synapse-worker@.service b/docs/systemd-with-workers/system/matrix-synapse-worker@.service
index 70589a7a51c1..39bc5e88e862 100644
--- a/docs/systemd-with-workers/system/matrix-synapse-worker@.service
+++ b/docs/systemd-with-workers/system/matrix-synapse-worker@.service
@@ -1,6 +1,6 @@
 [Unit]
 Description=Synapse %i
-
+AssertPathExists=/etc/matrix-synapse/workers/%i.yaml
 # This service should be restarted when the synapse target is restarted.
 PartOf=matrix-synapse.target
 
diff --git a/docs/tcp_replication.md b/docs/tcp_replication.md
index ab2fffbfe40c..db318baa9dbc 100644
--- a/docs/tcp_replication.md
+++ b/docs/tcp_replication.md
@@ -219,10 +219,6 @@ Asks the server for the current position of all streams.
 
    Inform the server a pusher should be removed
 
-#### INVALIDATE_CACHE (C)
-
-   Inform the server a cache should be invalidated
-
 ### REMOTE_SERVER_UP (S, C)
 
    Inform other processes that a remote server may have come back online.
diff --git a/docs/turn-howto.md b/docs/turn-howto.md
index b8a2ba3e82b1..d4a726be660d 100644
--- a/docs/turn-howto.md
+++ b/docs/turn-howto.md
@@ -18,7 +18,7 @@ For TURN relaying with `coturn` to work, it must be hosted on a server/endpoint
 Hosting TURN behind a NAT (even with appropriate port forwarding) is known to cause issues
 and to often not work.
 
-## `coturn` Setup
+## `coturn` setup
 
 ### Initial installation
 
@@ -26,7 +26,13 @@ The TURN daemon `coturn` is available from a variety of sources such as native p
 
 #### Debian installation
 
-    # apt install coturn
+Just install the debian package:
+
+```sh
+apt install coturn
+```
+
+This will install and start a systemd service called `coturn`.
 
 #### Source installation
 
@@ -63,38 +69,52 @@ The TURN daemon `coturn` is available from a variety of sources such as native p
 1.  Consider your security settings. TURN lets users request a relay which will
     connect to arbitrary IP addresses and ports. The following configuration is
     suggested as a minimum starting point:
-    
+
         # VoIP traffic is all UDP. There is no reason to let users connect to arbitrary TCP endpoints via the relay.
         no-tcp-relay
-        
+
         # don't let the relay ever try to connect to private IP address ranges within your network (if any)
         # given the turn server is likely behind your firewall, remember to include any privileged public IPs too.
         denied-peer-ip=10.0.0.0-10.255.255.255
         denied-peer-ip=192.168.0.0-192.168.255.255
         denied-peer-ip=172.16.0.0-172.31.255.255
-        
+
         # special case the turn server itself so that client->TURN->TURN->client flows work
         allowed-peer-ip=10.0.0.1
-        
+
         # consider whether you want to limit the quota of relayed streams per user (or total) to avoid risk of DoS.
         user-quota=12 # 4 streams per video call, so 12 streams = 3 simultaneous relayed calls per user.
         total-quota=1200
 
-    Ideally coturn should refuse to relay traffic which isn't SRTP; see
-    <https://github.com/matrix-org/synapse/issues/2009>
+1.  Also consider supporting TLS/DTLS. To do this, add the following settings
+    to `turnserver.conf`:
+
+        # TLS certificates, including intermediate certs.
+        # For Let's Encrypt certificates, use `fullchain.pem` here.
+        cert=/path/to/fullchain.pem
+
+        # TLS private key file
+        pkey=/path/to/privkey.pem
 
 1.  Ensure your firewall allows traffic into the TURN server on the ports
-    you've configured it to listen on (remember to allow both TCP and UDP TURN
-    traffic)
+    you've configured it to listen on (By default: 3478 and 5349 for the TURN(s)
+    traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535
+    for the UDP relay.)
+
+1.  (Re)start the turn server:
 
-1.  If you've configured coturn to support TLS/DTLS, generate or import your
-    private key and certificate.
+    * If you used the Debian package (or have set up a systemd unit yourself):
+      ```sh
+      systemctl restart coturn
+      ```
 
-1.  Start the turn server:
+    * If you installed from source:
 
-         bin/turnserver -o
+      ```sh
+      bin/turnserver -o
+      ```
 
-## synapse Setup
+## Synapse setup
 
 Your home server configuration file needs the following extra keys:
 
@@ -126,7 +146,14 @@ As an example, here is the relevant section of the config file for matrix.org:
 
 After updating the homeserver configuration, you must restart synapse:
 
+  * If you use synctl:
+    ```sh
     cd /where/you/run/synapse
     ./synctl restart
+    ```
+  * If you use systemd:
+    ```
+    systemctl restart synapse.service
+    ```
 
 ..and your Home Server now supports VoIP relaying!
diff --git a/mypy.ini b/mypy.ini
index 69be2f67adf2..3533797d686e 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -75,3 +75,6 @@ ignore_missing_imports = True
 
 [mypy-jwt.*]
 ignore_missing_imports = True
+
+[mypy-authlib.*]
+ignore_missing_imports = True
diff --git a/scripts-dev/build_debian_packages b/scripts-dev/build_debian_packages
index 84eaec6a9512..e6f4bd1dcadf 100755
--- a/scripts-dev/build_debian_packages
+++ b/scripts-dev/build_debian_packages
@@ -24,9 +24,8 @@ DISTS = (
     "debian:sid",
     "ubuntu:xenial",
     "ubuntu:bionic",
-    "ubuntu:cosmic",
-    "ubuntu:disco",
     "ubuntu:eoan",
+    "ubuntu:focal",
 )
 
 DESC = '''\
diff --git a/scripts-dev/convert_server_keys.py b/scripts-dev/convert_server_keys.py
index 06b4c1e2ff13..961dc59f1134 100644
--- a/scripts-dev/convert_server_keys.py
+++ b/scripts-dev/convert_server_keys.py
@@ -3,8 +3,6 @@
 import sys
 import time
 
-import six
-
 import psycopg2
 import yaml
 from canonicaljson import encode_canonical_json
@@ -12,10 +10,7 @@
 from signedjson.sign import sign_json
 from unpaddedbase64 import encode_base64
 
-if six.PY2:
-    db_type = six.moves.builtins.buffer
-else:
-    db_type = memoryview
+db_binary_type = memoryview
 
 
 def select_v1_keys(connection):
@@ -72,7 +67,7 @@ def rows_v2(server, json):
     valid_until = json["valid_until_ts"]
     key_json = encode_canonical_json(json)
     for key_id in json["verify_keys"]:
-        yield (server, key_id, "-", valid_until, valid_until, db_type(key_json))
+        yield (server, key_id, "-", valid_until, valid_until, db_binary_type(key_json))
 
 
 def main():
diff --git a/scripts/synapse_port_db b/scripts/synapse_port_db
index e8b698f3ffe5..acd9ac4b7525 100755
--- a/scripts/synapse_port_db
+++ b/scripts/synapse_port_db
@@ -122,7 +122,7 @@ APPEND_ONLY_TABLES = [
     "presence_stream",
     "push_rules_stream",
     "ex_outlier_stream",
-    "cache_invalidation_stream",
+    "cache_invalidation_stream_by_instance",
     "public_room_list_stream",
     "state_group_edges",
     "stream_ordering_to_exterm",
@@ -188,7 +188,7 @@ class MockHomeserver:
         self.clock = Clock(reactor)
         self.config = config
         self.hostname = config.server_name
-        self.version_string = "Synapse/"+get_version_string(synapse)
+        self.version_string = "Synapse/" + get_version_string(synapse)
 
     def get_clock(self):
         return self.clock
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 977e26a04828..0abf4911729d 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -36,7 +36,7 @@
 except ImportError:
     pass
 
-__version__ = "1.13.0rc2"
+__version__ = "1.13.0"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index 1ad5ff9410ab..3c660318fca2 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -22,6 +22,7 @@
 from netaddr import IPAddress
 
 from twisted.internet import defer
+from twisted.web.server import Request
 
 import synapse.logging.opentracing as opentracing
 import synapse.types
@@ -37,7 +38,7 @@
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.events import EventBase
 from synapse.types import StateMap, UserID
-from synapse.util.caches import CACHE_SIZE_FACTOR, register_cache
+from synapse.util.caches import register_cache
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.metrics import Measure
 
@@ -73,7 +74,7 @@ def __init__(self, hs):
         self.store = hs.get_datastore()
         self.state = hs.get_state_handler()
 
-        self.token_cache = LruCache(CACHE_SIZE_FACTOR * 10000)
+        self.token_cache = LruCache(10000)
         register_cache("cache", "token_cache", self.token_cache)
 
         self._auth_blocking = AuthBlocking(self.hs)
@@ -162,19 +163,25 @@ def get_public_keys(self, invite_event):
 
     @defer.inlineCallbacks
     def get_user_by_req(
-        self, request, allow_guest=False, rights="access", allow_expired=False
+        self,
+        request: Request,
+        allow_guest: bool = False,
+        rights: str = "access",
+        allow_expired: bool = False,
     ):
         """ Get a registered user's ID.
 
         Args:
-            request - An HTTP request with an access_token query parameter.
-            allow_expired - Whether to allow the request through even if the account is
-                expired. If true, Synapse will still require an access token to be
-                provided but won't check if the account it belongs to has expired. This
-                works thanks to /login delivering access tokens regardless of accounts'
-                expiration.
+            request: An HTTP request with an access_token query parameter.
+            allow_guest: If False, will raise an AuthError if the user making the
+                request is a guest.
+            rights: The operation being performed; the access token must allow this
+            allow_expired: If True, allow the request through even if the account
+                is expired, or session token lifetime has ended. Note that
+                /login will deliver access tokens regardless of expiration.
+
         Returns:
-            defer.Deferred: resolves to a ``synapse.types.Requester`` object
+            defer.Deferred: resolves to a `synapse.types.Requester` object
         Raises:
             InvalidClientCredentialsError if no user by that token exists or the token
                 is invalid.
@@ -205,7 +212,9 @@ def get_user_by_req(
 
                 return synapse.types.create_requester(user_id, app_service=app_service)
 
-            user_info = yield self.get_user_by_access_token(access_token, rights)
+            user_info = yield self.get_user_by_access_token(
+                access_token, rights, allow_expired=allow_expired
+            )
             user = user_info["user"]
             token_id = user_info["token_id"]
             is_guest = user_info["is_guest"]
@@ -280,13 +289,17 @@ def _get_appservice_user_id(self, request):
         return user_id, app_service
 
     @defer.inlineCallbacks
-    def get_user_by_access_token(self, token, rights="access"):
+    def get_user_by_access_token(
+        self, token: str, rights: str = "access", allow_expired: bool = False,
+    ):
         """ Validate access token and get user_id from it
 
         Args:
-            token (str): The access token to get the user by.
-            rights (str): The operation being performed; the access token must
-                allow this.
+            token: The access token to get the user by
+            rights: The operation being performed; the access token must
+                allow this
+            allow_expired: If False, raises an InvalidClientTokenError
+                if the token is expired
         Returns:
             Deferred[dict]: dict that includes:
                `user` (UserID)
@@ -294,8 +307,10 @@ def get_user_by_access_token(self, token, rights="access"):
                `token_id` (int|None): access token id. May be None if guest
                `device_id` (str|None): device corresponding to access token
         Raises:
+            InvalidClientTokenError if a user by that token exists, but the token is
+                expired
             InvalidClientCredentialsError if no user by that token exists or the token
-                is invalid.
+                is invalid
         """
 
         if rights == "access":
@@ -304,7 +319,8 @@ def get_user_by_access_token(self, token, rights="access"):
             if r:
                 valid_until_ms = r["valid_until_ms"]
                 if (
-                    valid_until_ms is not None
+                    not allow_expired
+                    and valid_until_ms is not None
                     and valid_until_ms < self.clock.time_msec()
                 ):
                     # there was a valid access token, but it has expired.
@@ -575,7 +591,7 @@ async def check_can_change_room_list(self, room_id: str, user: UserID):
         return user_level >= send_level
 
     @staticmethod
-    def has_access_token(request):
+    def has_access_token(request: Request):
         """Checks if the request has an access_token.
 
         Returns:
@@ -586,7 +602,7 @@ def has_access_token(request):
         return bool(query_params) or bool(auth_headers)
 
     @staticmethod
-    def get_access_token_from_request(request):
+    def get_access_token_from_request(request: Request):
         """Extracts the access_token from the request.
 
         Args:
diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 871179749a78..d7baf2bc3989 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -58,7 +58,15 @@ class RoomVersion(object):
     enforce_key_validity = attr.ib()  # bool
 
     # bool: before MSC2261/MSC2432, m.room.aliases had special auth rules and redaction rules
-    special_case_aliases_auth = attr.ib(type=bool, default=False)
+    special_case_aliases_auth = attr.ib(type=bool)
+    # Strictly enforce canonicaljson, do not allow:
+    # * Integers outside the range of [-2 ^ 53 + 1, 2 ^ 53 - 1]
+    # * Floats
+    # * NaN, Infinity, -Infinity
+    strict_canonicaljson = attr.ib(type=bool)
+    # bool: MSC2209: Check 'notifications' key while verifying
+    # m.room.power_levels auth rules.
+    limit_notifications_power_levels = attr.ib(type=bool)
 
 
 class RoomVersions(object):
@@ -69,6 +77,8 @@ class RoomVersions(object):
         StateResolutionVersions.V1,
         enforce_key_validity=False,
         special_case_aliases_auth=True,
+        strict_canonicaljson=False,
+        limit_notifications_power_levels=False,
     )
     V2 = RoomVersion(
         "2",
@@ -77,6 +87,8 @@ class RoomVersions(object):
         StateResolutionVersions.V2,
         enforce_key_validity=False,
         special_case_aliases_auth=True,
+        strict_canonicaljson=False,
+        limit_notifications_power_levels=False,
     )
     V3 = RoomVersion(
         "3",
@@ -85,6 +97,8 @@ class RoomVersions(object):
         StateResolutionVersions.V2,
         enforce_key_validity=False,
         special_case_aliases_auth=True,
+        strict_canonicaljson=False,
+        limit_notifications_power_levels=False,
     )
     V4 = RoomVersion(
         "4",
@@ -93,6 +107,8 @@ class RoomVersions(object):
         StateResolutionVersions.V2,
         enforce_key_validity=False,
         special_case_aliases_auth=True,
+        strict_canonicaljson=False,
+        limit_notifications_power_levels=False,
     )
     V5 = RoomVersion(
         "5",
@@ -101,14 +117,18 @@ class RoomVersions(object):
         StateResolutionVersions.V2,
         enforce_key_validity=True,
         special_case_aliases_auth=True,
+        strict_canonicaljson=False,
+        limit_notifications_power_levels=False,
     )
-    MSC2432_DEV = RoomVersion(
-        "org.matrix.msc2432",
-        RoomDisposition.UNSTABLE,
+    V6 = RoomVersion(
+        "6",
+        RoomDisposition.STABLE,
         EventFormatVersions.V3,
         StateResolutionVersions.V2,
         enforce_key_validity=True,
         special_case_aliases_auth=False,
+        strict_canonicaljson=True,
+        limit_notifications_power_levels=True,
     )
 
 
@@ -120,6 +140,6 @@ class RoomVersions(object):
         RoomVersions.V3,
         RoomVersions.V4,
         RoomVersions.V5,
-        RoomVersions.MSC2432_DEV,
+        RoomVersions.V6,
     )
 }  # type: Dict[str, RoomVersion]
diff --git a/synapse/app/generic_worker.py b/synapse/app/generic_worker.py
index d78c79e0f925..d751c9772be2 100644
--- a/synapse/app/generic_worker.py
+++ b/synapse/app/generic_worker.py
@@ -26,7 +26,6 @@
 
 import synapse
 import synapse.events
-from synapse.api.constants import EventTypes
 from synapse.api.errors import SynapseError
 from synapse.api.urls import (
     CLIENT_API_PREFIX,
@@ -48,6 +47,7 @@
 from synapse.logging.context import LoggingContext
 from synapse.metrics import METRICS_PREFIX, MetricsResource, RegistryProxy
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.replication.http import REPLICATION_PREFIX, ReplicationRestResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
 from synapse.replication.slave.storage.account_data import SlavedAccountDataStore
 from synapse.replication.slave.storage.appservice import SlavedApplicationServiceStore
@@ -81,11 +81,6 @@
     ToDeviceStream,
     TypingStream,
 )
-from synapse.replication.tcp.streams.events import (
-    EventsStream,
-    EventsStreamEventRow,
-    EventsStreamRow,
-)
 from synapse.rest.admin import register_servlets_for_media_repo
 from synapse.rest.client.v1 import events
 from synapse.rest.client.v1.initial_sync import InitialSyncRestServlet
@@ -122,11 +117,13 @@
 from synapse.rest.client.versions import VersionsRestServlet
 from synapse.rest.key.v2 import KeyApiV2Resource
 from synapse.server import HomeServer
+from synapse.storage.data_stores.main.censor_events import CensorEventsStore
 from synapse.storage.data_stores.main.media_repository import MediaRepositoryStore
 from synapse.storage.data_stores.main.monthly_active_users import (
     MonthlyActiveUsersWorkerStore,
 )
 from synapse.storage.data_stores.main.presence import UserPresenceState
+from synapse.storage.data_stores.main.search import SearchWorkerStore
 from synapse.storage.data_stores.main.ui_auth import UIAuthWorkerStore
 from synapse.storage.data_stores.main.user_directory import UserDirectoryStore
 from synapse.types import ReadReceipt
@@ -429,6 +426,7 @@ class GenericWorkerSlavedStore(
     SlavedGroupServerStore,
     SlavedAccountDataStore,
     SlavedPusherStore,
+    CensorEventsStore,
     SlavedEventStore,
     SlavedKeyStore,
     RoomStore,
@@ -442,6 +440,7 @@ class GenericWorkerSlavedStore(
     SlavedFilteringStore,
     MonthlyActiveUsersWorkerStore,
     MediaRepositoryStore,
+    SearchWorkerStore,
     BaseSlavedStore,
 ):
     def __init__(self, database, db_conn, hs):
@@ -559,6 +558,9 @@ def _listen_http(self, listener_config):
                 if name in ["keys", "federation"]:
                     resources[SERVER_KEY_V2_PREFIX] = KeyApiV2Resource(self)
 
+                if name == "replication":
+                    resources[REPLICATION_PREFIX] = ReplicationRestResource(self)
+
         root_resource = create_resource_tree(resources, NoResource())
 
         _base.listen_tcp(
@@ -618,7 +620,7 @@ def build_typing_handler(self):
 
 class GenericWorkerReplicationHandler(ReplicationDataHandler):
     def __init__(self, hs):
-        super(GenericWorkerReplicationHandler, self).__init__(hs.get_datastore())
+        super(GenericWorkerReplicationHandler, self).__init__(hs)
 
         self.store = hs.get_datastore()
         self.typing_handler = hs.get_typing_handler()
@@ -644,30 +646,7 @@ async def _process_and_notify(self, stream_name, instance_name, token, rows):
                     stream_name, token, rows
                 )
 
-            if stream_name == EventsStream.NAME:
-                # We shouldn't get multiple rows per token for events stream, so
-                # we don't need to optimise this for multiple rows.
-                for row in rows:
-                    if row.type != EventsStreamEventRow.TypeId:
-                        continue
-                    assert isinstance(row, EventsStreamRow)
-
-                    event = await self.store.get_event(
-                        row.data.event_id, allow_rejected=True
-                    )
-                    if event.rejected_reason:
-                        continue
-
-                    extra_users = ()
-                    if event.type == EventTypes.Member:
-                        extra_users = (event.state_key,)
-                    max_token = self.store.get_room_max_stream_ordering()
-                    self.notifier.on_new_room_event(
-                        event, token, max_token, extra_users
-                    )
-
-                await self.pusher_pool.on_new_notifications(token, token)
-            elif stream_name == PushRulesStream.NAME:
+            if stream_name == PushRulesStream.NAME:
                 self.notifier.on_new_event(
                     "push_rules_key", token, users=[row.user_id for row in rows]
                 )
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index cbd1ea475add..d7f337e586ca 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -69,7 +69,6 @@
 from synapse.storage import DataStore
 from synapse.storage.engines import IncorrectDatabaseSetup
 from synapse.storage.prepare_database import UpgradeDatabaseException
-from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.manhole import manhole
 from synapse.util.module_loader import load_module
@@ -192,6 +191,11 @@ def _configure_named_resource(self, name, compress=False):
                 }
             )
 
+            if self.get_config().oidc_enabled:
+                from synapse.rest.oidc import OIDCResource
+
+                resources["/_synapse/oidc"] = OIDCResource(self)
+
             if self.get_config().saml2_enabled:
                 from synapse.rest.saml2 import SAML2Resource
 
@@ -422,6 +426,13 @@ def start():
                 # Check if it needs to be reprovisioned every day.
                 hs.get_clock().looping_call(reprovision_acme, 24 * 60 * 60 * 1000)
 
+            # Load the OIDC provider metadatas, if OIDC is enabled.
+            if hs.config.oidc_enabled:
+                oidc = hs.get_oidc_handler()
+                # Loading the provider metadata also ensures the provider config is valid.
+                yield defer.ensureDeferred(oidc.load_metadata())
+                yield defer.ensureDeferred(oidc.load_jwks())
+
             _base.start(hs, config.listeners)
 
             hs.get_datastore().db.updates.start_doing_background_updates()
@@ -504,8 +515,8 @@ def phone_stats_home(hs, stats, stats_process=_stats_process):
 
     daily_sent_messages = yield hs.get_datastore().count_daily_sent_messages()
     stats["daily_sent_messages"] = daily_sent_messages
-    stats["cache_factor"] = CACHE_SIZE_FACTOR
-    stats["event_cache_size"] = hs.config.event_cache_size
+    stats["cache_factor"] = hs.config.caches.global_factor
+    stats["event_cache_size"] = hs.config.caches.event_cache_size
 
     #
     # Performance statistics
diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index aea3985a5f48..1b13e8442581 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -270,7 +270,7 @@ def is_exclusive_alias(self, alias):
     def is_exclusive_room(self, room_id):
         return self._is_exclusive(ApplicationService.NS_ROOMS, room_id)
 
-    def get_exlusive_user_regexes(self):
+    def get_exclusive_user_regexes(self):
         """Get the list of regexes used to determine if a user is exclusively
         registered by the AS
         """
diff --git a/synapse/config/_base.pyi b/synapse/config/_base.pyi
index 3053fc9d27e5..9e576060d4df 100644
--- a/synapse/config/_base.pyi
+++ b/synapse/config/_base.pyi
@@ -13,6 +13,7 @@ from synapse.config import (
     key,
     logger,
     metrics,
+    oidc_config,
     password,
     password_auth_providers,
     push,
@@ -59,6 +60,7 @@ class RootConfig:
     saml2: saml2_config.SAML2Config
     cas: cas.CasConfig
     sso: sso.SSOConfig
+    oidc: oidc_config.OIDCConfig
     jwt: jwt_config.JWTConfig
     password: password.PasswordConfig
     email: emailconfig.EmailConfig
diff --git a/synapse/config/cache.py b/synapse/config/cache.py
new file mode 100644
index 000000000000..91036a012e2b
--- /dev/null
+++ b/synapse/config/cache.py
@@ -0,0 +1,164 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+from typing import Callable, Dict
+
+from ._base import Config, ConfigError
+
+# The prefix for all cache factor-related environment variables
+_CACHES = {}
+_CACHE_PREFIX = "SYNAPSE_CACHE_FACTOR"
+_DEFAULT_FACTOR_SIZE = 0.5
+_DEFAULT_EVENT_CACHE_SIZE = "10K"
+
+
+class CacheProperties(object):
+    def __init__(self):
+        # The default factor size for all caches
+        self.default_factor_size = float(
+            os.environ.get(_CACHE_PREFIX, _DEFAULT_FACTOR_SIZE)
+        )
+        self.resize_all_caches_func = None
+
+
+properties = CacheProperties()
+
+
+def add_resizable_cache(cache_name: str, cache_resize_callback: Callable):
+    """Register a cache that's size can dynamically change
+
+    Args:
+        cache_name: A reference to the cache
+        cache_resize_callback: A callback function that will be ran whenever
+            the cache needs to be resized
+    """
+    _CACHES[cache_name.lower()] = cache_resize_callback
+
+    # Ensure all loaded caches are sized appropriately
+    #
+    # This method should only run once the config has been read,
+    # as it uses values read from it
+    if properties.resize_all_caches_func:
+        properties.resize_all_caches_func()
+
+
+class CacheConfig(Config):
+    section = "caches"
+    _environ = os.environ
+
+    @staticmethod
+    def reset():
+        """Resets the caches to their defaults. Used for tests."""
+        properties.default_factor_size = float(
+            os.environ.get(_CACHE_PREFIX, _DEFAULT_FACTOR_SIZE)
+        )
+        properties.resize_all_caches_func = None
+        _CACHES.clear()
+
+    def generate_config_section(self, **kwargs):
+        return """\
+        ## Caching ##
+
+        # Caching can be configured through the following options.
+        #
+        # A cache 'factor' is a multiplier that can be applied to each of
+        # Synapse's caches in order to increase or decrease the maximum
+        # number of entries that can be stored.
+
+        # The number of events to cache in memory. Not affected by
+        # caches.global_factor.
+        #
+        #event_cache_size: 10K
+
+        caches:
+           # Controls the global cache factor, which is the default cache factor
+           # for all caches if a specific factor for that cache is not otherwise
+           # set.
+           #
+           # This can also be set by the "SYNAPSE_CACHE_FACTOR" environment
+           # variable. Setting by environment variable takes priority over
+           # setting through the config file.
+           #
+           # Defaults to 0.5, which will half the size of all caches.
+           #
+           #global_factor: 1.0
+
+           # A dictionary of cache name to cache factor for that individual
+           # cache. Overrides the global cache factor for a given cache.
+           #
+           # These can also be set through environment variables comprised
+           # of "SYNAPSE_CACHE_FACTOR_" + the name of the cache in capital
+           # letters and underscores. Setting by environment variable
+           # takes priority over setting through the config file.
+           # Ex. SYNAPSE_CACHE_FACTOR_GET_USERS_WHO_SHARE_ROOM_WITH_USER=2.0
+           #
+           per_cache_factors:
+             #get_users_who_share_room_with_user: 2.0
+        """
+
+    def read_config(self, config, **kwargs):
+        self.event_cache_size = self.parse_size(
+            config.get("event_cache_size", _DEFAULT_EVENT_CACHE_SIZE)
+        )
+        self.cache_factors = {}  # type: Dict[str, float]
+
+        cache_config = config.get("caches") or {}
+        self.global_factor = cache_config.get(
+            "global_factor", properties.default_factor_size
+        )
+        if not isinstance(self.global_factor, (int, float)):
+            raise ConfigError("caches.global_factor must be a number.")
+
+        # Set the global one so that it's reflected in new caches
+        properties.default_factor_size = self.global_factor
+
+        # Load cache factors from the config
+        individual_factors = cache_config.get("per_cache_factors") or {}
+        if not isinstance(individual_factors, dict):
+            raise ConfigError("caches.per_cache_factors must be a dictionary")
+
+        # Override factors from environment if necessary
+        individual_factors.update(
+            {
+                key[len(_CACHE_PREFIX) + 1 :].lower(): float(val)
+                for key, val in self._environ.items()
+                if key.startswith(_CACHE_PREFIX + "_")
+            }
+        )
+
+        for cache, factor in individual_factors.items():
+            if not isinstance(factor, (int, float)):
+                raise ConfigError(
+                    "caches.per_cache_factors.%s must be a number" % (cache.lower(),)
+                )
+            self.cache_factors[cache.lower()] = factor
+
+        # Resize all caches (if necessary) with the new factors we've loaded
+        self.resize_all_caches()
+
+        # Store this function so that it can be called from other classes without
+        # needing an instance of Config
+        properties.resize_all_caches_func = self.resize_all_caches
+
+    def resize_all_caches(self):
+        """Ensure all cache sizes are up to date
+
+        For each cache, run the mapped callback function with either
+        a specific cache factor or the default, global one.
+        """
+        for cache_name, callback in _CACHES.items():
+            new_factor = self.cache_factors.get(cache_name, self.global_factor)
+            callback(new_factor)
diff --git a/synapse/config/database.py b/synapse/config/database.py
index 5b662d1b0138..1064c2697b30 100644
--- a/synapse/config/database.py
+++ b/synapse/config/database.py
@@ -68,10 +68,6 @@
   name: sqlite3
   args:
     database: %(database_path)s
-
-# Number of events to cache in memory.
-#
-#event_cache_size: 10K
 """
 
 
@@ -116,8 +112,6 @@ def __init__(self, *args, **kwargs):
         self.databases = []
 
     def read_config(self, config, **kwargs):
-        self.event_cache_size = self.parse_size(config.get("event_cache_size", "10K"))
-
         # We *experimentally* support specifying multiple databases via the
         # `databases` key. This is a map from a label to database config in the
         # same format as the `database` config option, plus an extra
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index be6c6afa7469..2c7b3a699fd9 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -17,6 +17,7 @@
 from ._base import RootConfig
 from .api import ApiConfig
 from .appservice import AppServiceConfig
+from .cache import CacheConfig
 from .captcha import CaptchaConfig
 from .cas import CasConfig
 from .consent_config import ConsentConfig
@@ -27,6 +28,7 @@
 from .key import KeyConfig
 from .logger import LoggingConfig
 from .metrics import MetricsConfig
+from .oidc_config import OIDCConfig
 from .password import PasswordConfig
 from .password_auth_providers import PasswordAuthProviderConfig
 from .push import PushConfig
@@ -54,6 +56,7 @@ class HomeServerConfig(RootConfig):
     config_classes = [
         ServerConfig,
         TlsConfig,
+        CacheConfig,
         DatabaseConfig,
         LoggingConfig,
         RatelimitConfig,
@@ -66,6 +69,7 @@ class HomeServerConfig(RootConfig):
         AppServiceConfig,
         KeyConfig,
         SAML2Config,
+        OIDCConfig,
         CasConfig,
         SSOConfig,
         JWTConfig,
diff --git a/synapse/config/oidc_config.py b/synapse/config/oidc_config.py
new file mode 100644
index 000000000000..5af110745e40
--- /dev/null
+++ b/synapse/config/oidc_config.py
@@ -0,0 +1,177 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Quentin Gliech
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from synapse.python_dependencies import DependencyException, check_requirements
+from synapse.util.module_loader import load_module
+
+from ._base import Config, ConfigError
+
+DEFAULT_USER_MAPPING_PROVIDER = "synapse.handlers.oidc_handler.JinjaOidcMappingProvider"
+
+
+class OIDCConfig(Config):
+    section = "oidc"
+
+    def read_config(self, config, **kwargs):
+        self.oidc_enabled = False
+
+        oidc_config = config.get("oidc_config")
+
+        if not oidc_config or not oidc_config.get("enabled", False):
+            return
+
+        try:
+            check_requirements("oidc")
+        except DependencyException as e:
+            raise ConfigError(e.message)
+
+        public_baseurl = self.public_baseurl
+        if public_baseurl is None:
+            raise ConfigError("oidc_config requires a public_baseurl to be set")
+        self.oidc_callback_url = public_baseurl + "_synapse/oidc/callback"
+
+        self.oidc_enabled = True
+        self.oidc_discover = oidc_config.get("discover", True)
+        self.oidc_issuer = oidc_config["issuer"]
+        self.oidc_client_id = oidc_config["client_id"]
+        self.oidc_client_secret = oidc_config["client_secret"]
+        self.oidc_client_auth_method = oidc_config.get(
+            "client_auth_method", "client_secret_basic"
+        )
+        self.oidc_scopes = oidc_config.get("scopes", ["openid"])
+        self.oidc_authorization_endpoint = oidc_config.get("authorization_endpoint")
+        self.oidc_token_endpoint = oidc_config.get("token_endpoint")
+        self.oidc_userinfo_endpoint = oidc_config.get("userinfo_endpoint")
+        self.oidc_jwks_uri = oidc_config.get("jwks_uri")
+        self.oidc_subject_claim = oidc_config.get("subject_claim", "sub")
+        self.oidc_skip_verification = oidc_config.get("skip_verification", False)
+
+        ump_config = oidc_config.get("user_mapping_provider", {})
+        ump_config.setdefault("module", DEFAULT_USER_MAPPING_PROVIDER)
+        ump_config.setdefault("config", {})
+
+        (
+            self.oidc_user_mapping_provider_class,
+            self.oidc_user_mapping_provider_config,
+        ) = load_module(ump_config)
+
+        # Ensure loaded user mapping module has defined all necessary methods
+        required_methods = [
+            "get_remote_user_id",
+            "map_user_attributes",
+        ]
+        missing_methods = [
+            method
+            for method in required_methods
+            if not hasattr(self.oidc_user_mapping_provider_class, method)
+        ]
+        if missing_methods:
+            raise ConfigError(
+                "Class specified by oidc_config."
+                "user_mapping_provider.module is missing required "
+                "methods: %s" % (", ".join(missing_methods),)
+            )
+
+    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+        return """\
+        # Enable OpenID Connect for registration and login. Uses authlib.
+        #
+        oidc_config:
+            # enable OpenID Connect. Defaults to false.
+            #
+            #enabled: true
+
+            # use the OIDC discovery mechanism to discover endpoints. Defaults to true.
+            #
+            #discover: true
+
+            # the OIDC issuer. Used to validate tokens and discover the providers endpoints. Required.
+            #
+            #issuer: "https://accounts.example.com/"
+
+            # oauth2 client id to use. Required.
+            #
+            #client_id: "provided-by-your-issuer"
+
+            # oauth2 client secret to use. Required.
+            #
+            #client_secret: "provided-by-your-issuer"
+
+            # auth method to use when exchanging the token.
+            # Valid values are "client_secret_basic" (default), "client_secret_post" and "none".
+            #
+            #client_auth_method: "client_auth_basic"
+
+            # list of scopes to ask. This should include the "openid" scope. Defaults to ["openid"].
+            #
+            #scopes: ["openid"]
+
+            # the oauth2 authorization endpoint. Required if provider discovery is disabled.
+            #
+            #authorization_endpoint: "https://accounts.example.com/oauth2/auth"
+
+            # the oauth2 token endpoint. Required if provider discovery is disabled.
+            #
+            #token_endpoint: "https://accounts.example.com/oauth2/token"
+
+            # the OIDC userinfo endpoint. Required if discovery is disabled and the "openid" scope is not asked.
+            #
+            #userinfo_endpoint: "https://accounts.example.com/userinfo"
+
+            # URI where to fetch the JWKS. Required if discovery is disabled and the "openid" scope is used.
+            #
+            #jwks_uri: "https://accounts.example.com/.well-known/jwks.json"
+
+            # skip metadata verification. Defaults to false.
+            # Use this if you are connecting to a provider that is not OpenID Connect compliant.
+            # Avoid this in production.
+            #
+            #skip_verification: false
+
+
+            # An external module can be provided here as a custom solution to mapping
+            # attributes returned from a OIDC provider onto a matrix user.
+            #
+            user_mapping_provider:
+              # The custom module's class. Uncomment to use a custom module.
+              # Default is {mapping_provider!r}.
+              #
+              #module: mapping_provider.OidcMappingProvider
+
+              # Custom configuration values for the module. Below options are intended
+              # for the built-in provider, they should be changed if using a custom
+              # module. This section will be passed as a Python dictionary to the
+              # module's `parse_config` method.
+              #
+              # Below is the config of the default mapping provider, based on Jinja2
+              # templates. Those templates are used to render user attributes, where the
+              # userinfo object is available through the `user` variable.
+              #
+              config:
+                # name of the claim containing a unique identifier for the user.
+                # Defaults to `sub`, which OpenID Connect compliant providers should provide.
+                #
+                #subject_claim: "sub"
+
+                # Jinja2 template for the localpart of the MXID
+                #
+                localpart_template: "{{{{ user.preferred_username }}}}"
+
+                # Jinja2 template for the display name to set on first login. Optional.
+                #
+                #display_name_template: "{{{{ user.given_name }}}} {{{{ user.last_name }}}}"
+        """.format(
+            mapping_provider=DEFAULT_USER_MAPPING_PROVIDER
+        )
diff --git a/synapse/config/server_notices_config.py b/synapse/config/server_notices_config.py
index 6ea2ea886962..6c427b6f927e 100644
--- a/synapse/config/server_notices_config.py
+++ b/synapse/config/server_notices_config.py
@@ -51,7 +51,7 @@ class ServerNoticesConfig(Config):
             None if server notices are not enabled.
 
         server_notices_mxid_avatar_url (str|None):
-            The display name to use for the server notices user.
+            The MXC URL for the avatar of the server notices user.
             None if server notices are not enabled.
 
         server_notices_room_name (str|None):
diff --git a/synapse/config/spam_checker.py b/synapse/config/spam_checker.py
index 36e0ddab5c4d..3d067d29db28 100644
--- a/synapse/config/spam_checker.py
+++ b/synapse/config/spam_checker.py
@@ -13,6 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any, Dict, List, Tuple
+
+from synapse.config import ConfigError
 from synapse.util.module_loader import load_module
 
 from ._base import Config
@@ -22,16 +25,35 @@ class SpamCheckerConfig(Config):
     section = "spamchecker"
 
     def read_config(self, config, **kwargs):
-        self.spam_checker = None
+        self.spam_checkers = []  # type: List[Tuple[Any, Dict]]
+
+        spam_checkers = config.get("spam_checker") or []
+        if isinstance(spam_checkers, dict):
+            # The spam_checker config option used to only support one
+            # spam checker, and thus was simply a dictionary with module
+            # and config keys. Support this old behaviour by checking
+            # to see if the option resolves to a dictionary
+            self.spam_checkers.append(load_module(spam_checkers))
+        elif isinstance(spam_checkers, list):
+            for spam_checker in spam_checkers:
+                if not isinstance(spam_checker, dict):
+                    raise ConfigError("spam_checker syntax is incorrect")
 
-        provider = config.get("spam_checker", None)
-        if provider is not None:
-            self.spam_checker = load_module(provider)
+                self.spam_checkers.append(load_module(spam_checker))
+        else:
+            raise ConfigError("spam_checker syntax is incorrect")
 
     def generate_config_section(self, **kwargs):
         return """\
-        #spam_checker:
-        #  module: "my_custom_project.SuperSpamChecker"
-        #  config:
-        #    example_option: 'things'
+        # Spam checkers are third-party modules that can block specific actions
+        # of local users, such as creating rooms and registering undesirable
+        # usernames, as well as remote users by redacting incoming events.
+        #
+        spam_checker:
+           #- module: "my_custom_project.SuperSpamChecker"
+           #  config:
+           #    example_option: 'things'
+           #- module: "some_other_project.BadEventStopper"
+           #  config:
+           #    example_stop_events_from: ['@bad:example.com']
         """
diff --git a/synapse/config/sso.py b/synapse/config/sso.py
index cac6bc0139e8..aff642f01555 100644
--- a/synapse/config/sso.py
+++ b/synapse/config/sso.py
@@ -36,17 +36,13 @@ def read_config(self, config, **kwargs):
         if not template_dir:
             template_dir = pkg_resources.resource_filename("synapse", "res/templates",)
 
-        self.sso_redirect_confirm_template_dir = template_dir
+        self.sso_template_dir = template_dir
         self.sso_account_deactivated_template = self.read_file(
-            os.path.join(
-                self.sso_redirect_confirm_template_dir, "sso_account_deactivated.html"
-            ),
+            os.path.join(self.sso_template_dir, "sso_account_deactivated.html"),
             "sso_account_deactivated_template",
         )
         self.sso_auth_success_template = self.read_file(
-            os.path.join(
-                self.sso_redirect_confirm_template_dir, "sso_auth_success.html"
-            ),
+            os.path.join(self.sso_template_dir, "sso_auth_success.html"),
             "sso_auth_success_template",
         )
 
@@ -137,6 +133,13 @@ def generate_config_section(self, **kwargs):
             #
             #   This template has no additional variables.
             #
+            # * HTML page to display to users if something goes wrong during the
+            #   OpenID Connect authentication process: 'sso_error.html'.
+            #
+            #   When rendering, this template is given two variables:
+            #     * error: the technical name of the error
+            #     * error_description: a human-readable message for the error
+            #
             # You can see the default templates at:
             # https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
             #
diff --git a/synapse/config/workers.py b/synapse/config/workers.py
index fef72ed97474..c80c338584cf 100644
--- a/synapse/config/workers.py
+++ b/synapse/config/workers.py
@@ -13,9 +13,20 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import attr
+
 from ._base import Config
 
 
+@attr.s
+class InstanceLocationConfig:
+    """The host and port to talk to an instance via HTTP replication.
+    """
+
+    host = attr.ib(type=str)
+    port = attr.ib(type=int)
+
+
 class WorkerConfig(Config):
     """The workers are processes run separately to the main synapse process.
     They have their own pid_file and listener configuration. They use the
@@ -71,6 +82,12 @@ def read_config(self, config, **kwargs):
                 elif not bind_addresses:
                     bind_addresses.append("")
 
+        # A map from instance name to host/port of their HTTP replication endpoint.
+        instance_map = config.get("instance_map", {}) or {}
+        self.instance_map = {
+            name: InstanceLocationConfig(**c) for name, c in instance_map.items()
+        }
+
     def read_arguments(self, args):
         # We support a bunch of command line arguments that override options in
         # the config. A lot of these options have a worker_* prefix when running
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index 46beb5334fad..c58235514650 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 import logging
-from typing import Set, Tuple
+from typing import List, Optional, Set, Tuple
 
 from canonicaljson import encode_canonical_json
 from signedjson.key import decode_verify_key_bytes
@@ -29,18 +29,19 @@
     EventFormatVersions,
     RoomVersion,
 )
-from synapse.types import UserID, get_domain_from_id
+from synapse.events import EventBase
+from synapse.types import StateMap, UserID, get_domain_from_id
 
 logger = logging.getLogger(__name__)
 
 
 def check(
     room_version_obj: RoomVersion,
-    event,
-    auth_events,
-    do_sig_check=True,
-    do_size_check=True,
-):
+    event: EventBase,
+    auth_events: StateMap[EventBase],
+    do_sig_check: bool = True,
+    do_size_check: bool = True,
+) -> None:
     """ Checks if this event is correctly authed.
 
     Args:
@@ -181,7 +182,7 @@ def check(
     _can_send_event(event, auth_events)
 
     if event.type == EventTypes.PowerLevels:
-        _check_power_levels(event, auth_events)
+        _check_power_levels(room_version_obj, event, auth_events)
 
     if event.type == EventTypes.Redaction:
         check_redaction(room_version_obj, event, auth_events)
@@ -189,7 +190,7 @@ def check(
     logger.debug("Allowing! %s", event)
 
 
-def _check_size_limits(event):
+def _check_size_limits(event: EventBase) -> None:
     def too_big(field):
         raise EventSizeError("%s too large" % (field,))
 
@@ -207,13 +208,18 @@ def too_big(field):
         too_big("event")
 
 
-def _can_federate(event, auth_events):
+def _can_federate(event: EventBase, auth_events: StateMap[EventBase]) -> bool:
     creation_event = auth_events.get((EventTypes.Create, ""))
+    # There should always be a creation event, but if not don't federate.
+    if not creation_event:
+        return False
 
     return creation_event.content.get("m.federate", True) is True
 
 
-def _is_membership_change_allowed(event, auth_events):
+def _is_membership_change_allowed(
+    event: EventBase, auth_events: StateMap[EventBase]
+) -> None:
     membership = event.content["membership"]
 
     # Check if this is the room creator joining:
@@ -339,21 +345,25 @@ def _is_membership_change_allowed(event, auth_events):
         raise AuthError(500, "Unknown membership %s" % membership)
 
 
-def _check_event_sender_in_room(event, auth_events):
+def _check_event_sender_in_room(
+    event: EventBase, auth_events: StateMap[EventBase]
+) -> None:
     key = (EventTypes.Member, event.user_id)
     member_event = auth_events.get(key)
 
-    return _check_joined_room(member_event, event.user_id, event.room_id)
+    _check_joined_room(member_event, event.user_id, event.room_id)
 
 
-def _check_joined_room(member, user_id, room_id):
+def _check_joined_room(member: Optional[EventBase], user_id: str, room_id: str) -> None:
     if not member or member.membership != Membership.JOIN:
         raise AuthError(
             403, "User %s not in room %s (%s)" % (user_id, room_id, repr(member))
         )
 
 
-def get_send_level(etype, state_key, power_levels_event):
+def get_send_level(
+    etype: str, state_key: Optional[str], power_levels_event: Optional[EventBase]
+) -> int:
     """Get the power level required to send an event of a given type
 
     The federation spec [1] refers to this as "Required Power Level".
@@ -361,13 +371,13 @@ def get_send_level(etype, state_key, power_levels_event):
     https://matrix.org/docs/spec/server_server/unstable.html#definitions
 
     Args:
-        etype (str): type of event
-        state_key (str|None): state_key of state event, or None if it is not
+        etype: type of event
+        state_key: state_key of state event, or None if it is not
             a state event.
-        power_levels_event (synapse.events.EventBase|None): power levels event
+        power_levels_event: power levels event
             in force at this point in the room
     Returns:
-        int: power level required to send this event.
+        power level required to send this event.
     """
 
     if power_levels_event:
@@ -388,7 +398,7 @@ def get_send_level(etype, state_key, power_levels_event):
     return int(send_level)
 
 
-def _can_send_event(event, auth_events):
+def _can_send_event(event: EventBase, auth_events: StateMap[EventBase]) -> bool:
     power_levels_event = _get_power_level_event(auth_events)
 
     send_level = get_send_level(event.type, event.get("state_key"), power_levels_event)
@@ -410,7 +420,9 @@ def _can_send_event(event, auth_events):
     return True
 
 
-def check_redaction(room_version_obj: RoomVersion, event, auth_events):
+def check_redaction(
+    room_version_obj: RoomVersion, event: EventBase, auth_events: StateMap[EventBase],
+) -> bool:
     """Check whether the event sender is allowed to redact the target event.
 
     Returns:
@@ -442,7 +454,9 @@ def check_redaction(room_version_obj: RoomVersion, event, auth_events):
     raise AuthError(403, "You don't have permission to redact events")
 
 
-def _check_power_levels(event, auth_events):
+def _check_power_levels(
+    room_version_obj: RoomVersion, event: EventBase, auth_events: StateMap[EventBase],
+) -> None:
     user_list = event.content.get("users", {})
     # Validate users
     for k, v in user_list.items():
@@ -473,7 +487,7 @@ def _check_power_levels(event, auth_events):
         ("redact", None),
         ("kick", None),
         ("invite", None),
-    ]
+    ]  # type: List[Tuple[str, Optional[str]]]
 
     old_list = current_state.content.get("users", {})
     for user in set(list(old_list) + list(user_list)):
@@ -484,6 +498,14 @@ def _check_power_levels(event, auth_events):
     for ev_id in set(list(old_list) + list(new_list)):
         levels_to_check.append((ev_id, "events"))
 
+    # MSC2209 specifies these checks should also be done for the "notifications"
+    # key.
+    if room_version_obj.limit_notifications_power_levels:
+        old_list = current_state.content.get("notifications", {})
+        new_list = event.content.get("notifications", {})
+        for ev_id in set(list(old_list) + list(new_list)):
+            levels_to_check.append((ev_id, "notifications"))
+
     old_state = current_state.content
     new_state = event.content
 
@@ -495,12 +517,12 @@ def _check_power_levels(event, auth_events):
             new_loc = new_loc.get(dir, {})
 
         if level_to_check in old_loc:
-            old_level = int(old_loc[level_to_check])
+            old_level = int(old_loc[level_to_check])  # type: Optional[int]
         else:
             old_level = None
 
         if level_to_check in new_loc:
-            new_level = int(new_loc[level_to_check])
+            new_level = int(new_loc[level_to_check])  # type: Optional[int]
         else:
             new_level = None
 
@@ -526,21 +548,21 @@ def _check_power_levels(event, auth_events):
             )
 
 
-def _get_power_level_event(auth_events):
+def _get_power_level_event(auth_events: StateMap[EventBase]) -> Optional[EventBase]:
     return auth_events.get((EventTypes.PowerLevels, ""))
 
 
-def get_user_power_level(user_id, auth_events):
+def get_user_power_level(user_id: str, auth_events: StateMap[EventBase]) -> int:
     """Get a user's power level
 
     Args:
-        user_id (str): user's id to look up in power_levels
-        auth_events (dict[(str, str), synapse.events.EventBase]):
+        user_id: user's id to look up in power_levels
+        auth_events:
             state in force at this point in the room (or rather, a subset of
             it including at least the create event and power levels event.
 
     Returns:
-        int: the user's power level in this room.
+        the user's power level in this room.
     """
     power_level_event = _get_power_level_event(auth_events)
     if power_level_event:
@@ -566,7 +588,7 @@ def get_user_power_level(user_id, auth_events):
             return 0
 
 
-def _get_named_level(auth_events, name, default):
+def _get_named_level(auth_events: StateMap[EventBase], name: str, default: int) -> int:
     power_level_event = _get_power_level_event(auth_events)
 
     if not power_level_event:
@@ -579,7 +601,7 @@ def _get_named_level(auth_events, name, default):
         return default
 
 
-def _verify_third_party_invite(event, auth_events):
+def _verify_third_party_invite(event: EventBase, auth_events: StateMap[EventBase]):
     """
     Validates that the invite event is authorized by a previous third-party invite.
 
@@ -654,7 +676,7 @@ def get_public_keys(invite_event):
     return public_keys
 
 
-def auth_types_for_event(event) -> Set[Tuple[str, str]]:
+def auth_types_for_event(event: EventBase) -> Set[Tuple[str, str]]:
     """Given an event, return a list of (EventType, StateKey) that may be
     needed to auth the event. The returned list may be a superset of what
     would actually be required depending on the full state of the room.
diff --git a/synapse/events/spamcheck.py b/synapse/events/spamcheck.py
index a23b6b7b6137..1ffc9525d163 100644
--- a/synapse/events/spamcheck.py
+++ b/synapse/events/spamcheck.py
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 import inspect
-from typing import Dict
+from typing import Any, Dict, List
 
 from synapse.spam_checker_api import SpamCheckerApi
 
@@ -26,24 +26,17 @@
 
 class SpamChecker(object):
     def __init__(self, hs: "synapse.server.HomeServer"):
-        self.spam_checker = None
+        self.spam_checkers = []  # type: List[Any]
 
-        module = None
-        config = None
-        try:
-            module, config = hs.config.spam_checker
-        except Exception:
-            pass
-
-        if module is not None:
+        for module, config in hs.config.spam_checkers:
             # Older spam checkers don't accept the `api` argument, so we
             # try and detect support.
             spam_args = inspect.getfullargspec(module)
             if "api" in spam_args.args:
                 api = SpamCheckerApi(hs)
-                self.spam_checker = module(config=config, api=api)
+                self.spam_checkers.append(module(config=config, api=api))
             else:
-                self.spam_checker = module(config=config)
+                self.spam_checkers.append(module(config=config))
 
     def check_event_for_spam(self, event: "synapse.events.EventBase") -> bool:
         """Checks if a given event is considered "spammy" by this server.
@@ -58,10 +51,11 @@ def check_event_for_spam(self, event: "synapse.events.EventBase") -> bool:
         Returns:
             True if the event is spammy.
         """
-        if self.spam_checker is None:
-            return False
+        for spam_checker in self.spam_checkers:
+            if spam_checker.check_event_for_spam(event):
+                return True
 
-        return self.spam_checker.check_event_for_spam(event)
+        return False
 
     def user_may_invite(
         self, inviter_userid: str, invitee_userid: str, room_id: str
@@ -78,12 +72,14 @@ def user_may_invite(
         Returns:
             True if the user may send an invite, otherwise False
         """
-        if self.spam_checker is None:
-            return True
+        for spam_checker in self.spam_checkers:
+            if (
+                spam_checker.user_may_invite(inviter_userid, invitee_userid, room_id)
+                is False
+            ):
+                return False
 
-        return self.spam_checker.user_may_invite(
-            inviter_userid, invitee_userid, room_id
-        )
+        return True
 
     def user_may_create_room(self, userid: str) -> bool:
         """Checks if a given user may create a room
@@ -96,10 +92,11 @@ def user_may_create_room(self, userid: str) -> bool:
         Returns:
             True if the user may create a room, otherwise False
         """
-        if self.spam_checker is None:
-            return True
+        for spam_checker in self.spam_checkers:
+            if spam_checker.user_may_create_room(userid) is False:
+                return False
 
-        return self.spam_checker.user_may_create_room(userid)
+        return True
 
     def user_may_create_room_alias(self, userid: str, room_alias: str) -> bool:
         """Checks if a given user may create a room alias
@@ -113,10 +110,11 @@ def user_may_create_room_alias(self, userid: str, room_alias: str) -> bool:
         Returns:
             True if the user may create a room alias, otherwise False
         """
-        if self.spam_checker is None:
-            return True
+        for spam_checker in self.spam_checkers:
+            if spam_checker.user_may_create_room_alias(userid, room_alias) is False:
+                return False
 
-        return self.spam_checker.user_may_create_room_alias(userid, room_alias)
+        return True
 
     def user_may_publish_room(self, userid: str, room_id: str) -> bool:
         """Checks if a given user may publish a room to the directory
@@ -130,10 +128,11 @@ def user_may_publish_room(self, userid: str, room_id: str) -> bool:
         Returns:
             True if the user may publish the room, otherwise False
         """
-        if self.spam_checker is None:
-            return True
+        for spam_checker in self.spam_checkers:
+            if spam_checker.user_may_publish_room(userid, room_id) is False:
+                return False
 
-        return self.spam_checker.user_may_publish_room(userid, room_id)
+        return True
 
     def check_username_for_spam(self, user_profile: Dict[str, str]) -> bool:
         """Checks if a user ID or display name are considered "spammy" by this server.
@@ -150,13 +149,14 @@ def check_username_for_spam(self, user_profile: Dict[str, str]) -> bool:
         Returns:
             True if the user is spammy.
         """
-        if self.spam_checker is None:
-            return False
-
-        # For backwards compatibility, if the method does not exist on the spam checker, fallback to not interfering.
-        checker = getattr(self.spam_checker, "check_username_for_spam", None)
-        if not checker:
-            return False
-        # Make a copy of the user profile object to ensure the spam checker
-        # cannot modify it.
-        return checker(user_profile.copy())
+        for spam_checker in self.spam_checkers:
+            # For backwards compatibility, only run if the method exists on the
+            # spam checker
+            checker = getattr(spam_checker, "check_username_for_spam", None)
+            if checker:
+                # Make a copy of the user profile object to ensure the spam checker
+                # cannot modify it.
+                if checker(user_profile.copy()):
+                    return True
+
+        return False
diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index b75b097e5ef9..dd340be9a7ad 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 import collections
 import re
-from typing import Mapping, Union
+from typing import Any, Mapping, Union
 
 from six import string_types
 
@@ -23,6 +23,7 @@
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, RelationTypes
+from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import RoomVersion
 from synapse.util.async_helpers import yieldable_gather_results
 
@@ -449,3 +450,35 @@ def copy_power_levels_contents(
         raise TypeError("Invalid power_levels value for %s: %r" % (k, v))
 
     return power_levels
+
+
+def validate_canonicaljson(value: Any):
+    """
+    Ensure that the JSON object is valid according to the rules of canonical JSON.
+
+    See the appendix section 3.1: Canonical JSON.
+
+    This rejects JSON that has:
+    * An integer outside the range of [-2 ^ 53 + 1, 2 ^ 53 - 1]
+    * Floats
+    * NaN, Infinity, -Infinity
+    """
+    if isinstance(value, int):
+        if value <= -(2 ** 53) or 2 ** 53 <= value:
+            raise SynapseError(400, "JSON integer out of range", Codes.BAD_JSON)
+
+    elif isinstance(value, float):
+        # Note that Infinity, -Infinity, and NaN are also considered floats.
+        raise SynapseError(400, "Bad JSON value: float", Codes.BAD_JSON)
+
+    elif isinstance(value, (dict, frozendict)):
+        for v in value.values():
+            validate_canonicaljson(v)
+
+    elif isinstance(value, (list, tuple)):
+        for i in value:
+            validate_canonicaljson(i)
+
+    elif not isinstance(value, (bool, str)) and value is not None:
+        # Other potential JSON values (bool, None, str) are safe.
+        raise SynapseError(400, "Unknown JSON value", Codes.BAD_JSON)
diff --git a/synapse/events/validator.py b/synapse/events/validator.py
index 9b90c9ce04bd..b001c64bb4f8 100644
--- a/synapse/events/validator.py
+++ b/synapse/events/validator.py
@@ -18,6 +18,7 @@
 from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes, Membership
 from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import EventFormatVersions
+from synapse.events.utils import validate_canonicaljson
 from synapse.types import EventID, RoomID, UserID
 
 
@@ -55,6 +56,12 @@ def validate_new(self, event, config):
             if not isinstance(getattr(event, s), string_types):
                 raise SynapseError(400, "'%s' not a string type" % (s,))
 
+        # Depending on the room version, ensure the data is spec compliant JSON.
+        if event.room_version.strict_canonicaljson:
+            # Note that only the client controlled portion of the event is
+            # checked, since we trust the portions of the event we created.
+            validate_canonicaljson(event.content)
+
         if event.type == EventTypes.Aliases:
             if "aliases" in event.content:
                 for alias in event.content["aliases"]:
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index 4b115aac04f0..c0012c687242 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -29,7 +29,7 @@
 from synapse.crypto.event_signing import check_event_content_hash
 from synapse.crypto.keyring import Keyring
 from synapse.events import EventBase, make_event_from_dict
-from synapse.events.utils import prune_event
+from synapse.events.utils import prune_event, validate_canonicaljson
 from synapse.http.servlet import assert_params_in_dict
 from synapse.logging.context import (
     PreserveLoggingContext,
@@ -302,6 +302,10 @@ def event_from_pdu_json(
     elif depth > MAX_DEPTH:
         raise SynapseError(400, "Depth too large", Codes.BAD_JSON)
 
+    # Validate that the JSON conforms to the specification.
+    if room_version.strict_canonicaljson:
+        validate_canonicaljson(pdu_json)
+
     event = make_event_from_dict(pdu_json, room_version)
     event.internal_metadata.outlier = outlier
 
diff --git a/synapse/federation/send_queue.py b/synapse/federation/send_queue.py
index e1700ca8aa1c..52f4f54215dc 100644
--- a/synapse/federation/send_queue.py
+++ b/synapse/federation/send_queue.py
@@ -31,6 +31,7 @@
 
 import logging
 from collections import namedtuple
+from typing import Dict, List, Tuple, Type
 
 from six import iteritems
 
@@ -56,21 +57,35 @@ def __init__(self, hs):
         self.notifier = hs.get_notifier()
         self.is_mine_id = hs.is_mine_id
 
-        self.presence_map = {}  # Pending presence map user_id -> UserPresenceState
-        self.presence_changed = SortedDict()  # Stream position -> list[user_id]
+        # Pending presence map user_id -> UserPresenceState
+        self.presence_map = {}  # type: Dict[str, UserPresenceState]
+
+        # Stream position -> list[user_id]
+        self.presence_changed = SortedDict()  # type: SortedDict[int, List[str]]
 
         # Stores the destinations we need to explicitly send presence to about a
         # given user.
         # Stream position -> (user_id, destinations)
-        self.presence_destinations = SortedDict()
+        self.presence_destinations = (
+            SortedDict()
+        )  # type: SortedDict[int, Tuple[str, List[str]]]
+
+        # (destination, key) -> EDU
+        self.keyed_edu = {}  # type: Dict[Tuple[str, tuple], Edu]
 
-        self.keyed_edu = {}  # (destination, key) -> EDU
-        self.keyed_edu_changed = SortedDict()  # stream position -> (destination, key)
+        # stream position -> (destination, key)
+        self.keyed_edu_changed = (
+            SortedDict()
+        )  # type: SortedDict[int, Tuple[str, tuple]]
 
-        self.edus = SortedDict()  # stream position -> Edu
+        self.edus = SortedDict()  # type: SortedDict[int, Edu]
 
+        # stream ID for the next entry into presence_changed/keyed_edu_changed/edus.
         self.pos = 1
-        self.pos_time = SortedDict()
+
+        # map from stream ID to the time that stream entry was generated, so that we
+        # can clear out entries after a while
+        self.pos_time = SortedDict()  # type: SortedDict[int, int]
 
         # EVERYTHING IS SAD. In particular, python only makes new scopes when
         # we make a new function, so we need to make a new function so the inner
@@ -158,8 +173,10 @@ def _clear_queue_before_pos(self, position_to_delete):
             for edu_key in self.keyed_edu_changed.values():
                 live_keys.add(edu_key)
 
-            to_del = [edu_key for edu_key in self.keyed_edu if edu_key not in live_keys]
-            for edu_key in to_del:
+            keys_to_del = [
+                edu_key for edu_key in self.keyed_edu if edu_key not in live_keys
+            ]
+            for edu_key in keys_to_del:
                 del self.keyed_edu[edu_key]
 
             # Delete things out of edu map
@@ -250,19 +267,23 @@ def federation_ack(self, token):
         self._clear_queue_before_pos(token)
 
     async def get_replication_rows(
-        self, from_token, to_token, limit, federation_ack=None
-    ):
+        self, instance_name: str, from_token: int, to_token: int, target_row_count: int
+    ) -> Tuple[List[Tuple[int, Tuple]], int, bool]:
         """Get rows to be sent over federation between the two tokens
 
         Args:
-            from_token (int)
-            to_token(int)
-            limit (int)
-            federation_ack (int): Optional. The position where the worker is
-                explicitly acknowledged it has handled. Allows us to drop
-                data from before that point
+            instance_name: the name of the current process
+            from_token: the previous stream token: the starting point for fetching the
+                updates
+            to_token: the new stream token: the point to get updates up to
+            target_row_count: a target for the number of rows to be returned.
+
+        Returns: a triplet `(updates, new_last_token, limited)`, where:
+           * `updates` is a list of `(token, row)` entries.
+           * `new_last_token` is the new position in stream.
+           * `limited` is whether there are more updates to fetch.
         """
-        # TODO: Handle limit.
+        # TODO: Handle target_row_count.
 
         # To handle restarts where we wrap around
         if from_token > self.pos:
@@ -270,12 +291,7 @@ async def get_replication_rows(
 
         # list of tuple(int, BaseFederationRow), where the first is the position
         # of the federation stream.
-        rows = []
-
-        # There should be only one reader, so lets delete everything its
-        # acknowledged its seen.
-        if federation_ack:
-            self._clear_queue_before_pos(federation_ack)
+        rows = []  # type: List[Tuple[int, BaseFederationRow]]
 
         # Fetch changed presence
         i = self.presence_changed.bisect_right(from_token)
@@ -332,7 +348,11 @@ async def get_replication_rows(
         # Sort rows based on pos
         rows.sort()
 
-        return [(pos, row.TypeId, row.to_data()) for pos, row in rows]
+        return (
+            [(pos, (row.TypeId, row.to_data())) for pos, row in rows],
+            to_token,
+            False,
+        )
 
 
 class BaseFederationRow(object):
@@ -341,7 +361,7 @@ class BaseFederationRow(object):
     Specifies how to identify, serialize and deserialize the different types.
     """
 
-    TypeId = None  # Unique string that ids the type. Must be overriden in sub classes.
+    TypeId = ""  # Unique string that ids the type. Must be overriden in sub classes.
 
     @staticmethod
     def from_data(data):
@@ -454,10 +474,14 @@ def add_to_buffer(self, buff):
         buff.edus.setdefault(self.edu.destination, []).append(self.edu)
 
 
-TypeToRow = {
-    Row.TypeId: Row
-    for Row in (PresenceRow, PresenceDestinationsRow, KeyedEduRow, EduRow,)
-}
+_rowtypes = (
+    PresenceRow,
+    PresenceDestinationsRow,
+    KeyedEduRow,
+    EduRow,
+)  # type: Tuple[Type[BaseFederationRow], ...]
+
+TypeToRow = {Row.TypeId: Row for Row in _rowtypes}
 
 
 ParsedFederationStreamData = namedtuple(
diff --git a/synapse/federation/sender/__init__.py b/synapse/federation/sender/__init__.py
index 7d2f00574aaf..358268fcc57b 100644
--- a/synapse/federation/sender/__init__.py
+++ b/synapse/federation/sender/__init__.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 import logging
-from typing import Dict, Hashable, Iterable, List, Optional, Set
+from typing import Dict, Hashable, Iterable, List, Optional, Set, Tuple
 
 from six import itervalues
 
@@ -516,14 +516,16 @@ def wake_destination(self, destination: str):
 
         self._get_per_destination_queue(destination).attempt_new_transaction()
 
-    def get_current_token(self) -> int:
+    @staticmethod
+    def get_current_token() -> int:
         # Dummy implementation for case where federation sender isn't offloaded
         # to a worker.
         return 0
 
+    @staticmethod
     async def get_replication_rows(
-        self, from_token, to_token, limit, federation_ack=None
-    ):
+        instance_name: str, from_token: int, to_token: int, target_row_count: int
+    ) -> Tuple[List[Tuple[int, Tuple]], int, bool]:
         # Dummy implementation for case where federation sender isn't offloaded
         # to a worker.
-        return []
+        return [], 0, False
diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py
index c6f8e5ba1ed5..1093ae0d914c 100644
--- a/synapse/federation/sender/per_destination_queue.py
+++ b/synapse/federation/sender/per_destination_queue.py
@@ -16,11 +16,10 @@
 import datetime
 import logging
 import random
-from typing import Dict, Hashable, Iterable, List, Tuple
+from typing import TYPE_CHECKING, Dict, Hashable, Iterable, List, Tuple
 
 from prometheus_client import Counter
 
-import synapse.server
 from synapse.api.errors import (
     FederationDeniedError,
     HttpResponseException,
@@ -35,6 +34,9 @@
 from synapse.types import ReadReceipt
 from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter
 
+if TYPE_CHECKING:
+    import synapse.server
+
 # This is defined in the Matrix spec and enforced by the receiver.
 MAX_EDUS_PER_TRANSACTION = 100
 
@@ -81,6 +83,9 @@ def __init__(
 
         # a list of tuples of (pending pdu, order)
         self._pending_pdus = []  # type: List[Tuple[EventBase, int]]
+
+        # XXX this is never actually used: see
+        # https://github.com/matrix-org/synapse/issues/7549
         self._pending_edus = []  # type: List[Edu]
 
         # Pending EDUs by their "key". Keyed EDUs are EDUs that get clobbered
diff --git a/synapse/federation/sender/transaction_manager.py b/synapse/federation/sender/transaction_manager.py
index 7d3cc4a6c214..fa6ad9efdc34 100644
--- a/synapse/federation/sender/transaction_manager.py
+++ b/synapse/federation/sender/transaction_manager.py
@@ -13,11 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import List
+from typing import TYPE_CHECKING, List
 
 from canonicaljson import json
 
-import synapse.server
 from synapse.api.errors import HttpResponseException
 from synapse.events import EventBase
 from synapse.federation.persistence import TransactionActions
@@ -31,6 +30,9 @@
 )
 from synapse.util.metrics import measure_func
 
+if TYPE_CHECKING:
+    import synapse.server
+
 logger = logging.getLogger(__name__)
 
 
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 5c20e2917114..75b39e878c14 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -80,7 +80,9 @@ def __init__(self, hs):
         self.hs = hs  # FIXME better possibility to access registrationHandler later?
         self.macaroon_gen = hs.get_macaroon_generator()
         self._password_enabled = hs.config.password_enabled
-        self._sso_enabled = hs.config.saml2_enabled or hs.config.cas_enabled
+        self._sso_enabled = (
+            hs.config.cas_enabled or hs.config.saml2_enabled or hs.config.oidc_enabled
+        )
 
         # we keep this as a list despite the O(N^2) implication so that we can
         # keep PASSWORD first and avoid confusing clients which pick the first
@@ -126,13 +128,13 @@ def __init__(self, hs):
         # It notifies the user they are about to give access to their matrix account
         # to the client.
         self._sso_redirect_confirm_template = load_jinja2_templates(
-            hs.config.sso_redirect_confirm_template_dir, ["sso_redirect_confirm.html"],
+            hs.config.sso_template_dir, ["sso_redirect_confirm.html"],
         )[0]
         # The following template is shown during user interactive authentication
         # in the fallback auth scenario. It notifies the user that they are
         # authenticating for an operation to occur on their account.
         self._sso_auth_confirm_template = load_jinja2_templates(
-            hs.config.sso_redirect_confirm_template_dir, ["sso_auth_confirm.html"],
+            hs.config.sso_template_dir, ["sso_auth_confirm.html"],
         )[0]
         # The following template is shown after a successful user interactive
         # authentication session. It tells the user they can close the window.
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 4e5c64552553..81d859f807bb 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -2681,8 +2681,7 @@ async def on_exchange_third_party_invite_request(
         member_handler = self.hs.get_room_member_handler()
         await member_handler.send_membership_event(None, event, context)
 
-    @defer.inlineCallbacks
-    def add_display_name_to_third_party_invite(
+    async def add_display_name_to_third_party_invite(
         self, room_version, event_dict, event, context
     ):
         key = (
@@ -2690,10 +2689,10 @@ def add_display_name_to_third_party_invite(
             event.content["third_party_invite"]["signed"]["token"],
         )
         original_invite = None
-        prev_state_ids = yield context.get_prev_state_ids()
+        prev_state_ids = await context.get_prev_state_ids()
         original_invite_id = prev_state_ids.get(key)
         if original_invite_id:
-            original_invite = yield self.store.get_event(
+            original_invite = await self.store.get_event(
                 original_invite_id, allow_none=True
             )
         if original_invite:
@@ -2714,14 +2713,13 @@ def add_display_name_to_third_party_invite(
 
         builder = self.event_builder_factory.new(room_version, event_dict)
         EventValidator().validate_builder(builder)
-        event, context = yield self.event_creation_handler.create_new_client_event(
+        event, context = await self.event_creation_handler.create_new_client_event(
             builder=builder
         )
         EventValidator().validate_new(event, self.config)
         return (event, context)
 
-    @defer.inlineCallbacks
-    def _check_signature(self, event, context):
+    async def _check_signature(self, event, context):
         """
         Checks that the signature in the event is consistent with its invite.
 
@@ -2738,12 +2736,12 @@ def _check_signature(self, event, context):
         signed = event.content["third_party_invite"]["signed"]
         token = signed["token"]
 
-        prev_state_ids = yield context.get_prev_state_ids()
+        prev_state_ids = await context.get_prev_state_ids()
         invite_event_id = prev_state_ids.get((EventTypes.ThirdPartyInvite, token))
 
         invite_event = None
         if invite_event_id:
-            invite_event = yield self.store.get_event(invite_event_id, allow_none=True)
+            invite_event = await self.store.get_event(invite_event_id, allow_none=True)
 
         if not invite_event:
             raise AuthError(403, "Could not find invite")
@@ -2792,7 +2790,7 @@ def _check_signature(self, event, context):
                             raise
                         try:
                             if "key_validity_url" in public_key_object:
-                                yield self._check_key_revocation(
+                                await self._check_key_revocation(
                                     public_key, public_key_object["key_validity_url"]
                                 )
                         except Exception:
@@ -2806,8 +2804,7 @@ def _check_signature(self, event, context):
                 last_exception = e
         raise last_exception
 
-    @defer.inlineCallbacks
-    def _check_key_revocation(self, public_key, url):
+    async def _check_key_revocation(self, public_key, url):
         """
         Checks whether public_key has been revoked.
 
@@ -2821,7 +2818,7 @@ def _check_key_revocation(self, public_key, url):
                 for revocation.
         """
         try:
-            response = yield self.http_client.get_json(url, {"public_key": public_key})
+            response = await self.http_client.get_json(url, {"public_key": public_key})
         except Exception:
             raise SynapseError(502, "Third party certificate could not be checked")
         if "valid" not in response or not response["valid"]:
@@ -2916,8 +2913,7 @@ async def user_joined_room(self, user: UserID, room_id: str) -> None:
         else:
             user_joined_room(self.distributor, user, room_id)
 
-    @defer.inlineCallbacks
-    def get_room_complexity(self, remote_room_hosts, room_id):
+    async def get_room_complexity(self, remote_room_hosts, room_id):
         """
         Fetch the complexity of a remote room over federation.
 
@@ -2931,12 +2927,12 @@ def get_room_complexity(self, remote_room_hosts, room_id):
         """
 
         for host in remote_room_hosts:
-            res = yield self.federation_client.get_room_complexity(host, room_id)
+            res = await self.federation_client.get_room_complexity(host, room_id)
 
             # We got a result, return it.
             if res:
-                defer.returnValue(res)
+                return res
 
         # We fell off the bottom, couldn't get the complexity from anyone. Oh
         # well.
-        defer.returnValue(None)
+        return None
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 71c3a420abab..a83c03da9ac5 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -72,7 +72,6 @@ def __init__(self, hs):
         self.state_store = self.storage.state
         self._event_serializer = hs.get_event_client_serializer()
         self._ephemeral_events_enabled = hs.config.enable_ephemeral_messages
-        self._is_worker_app = bool(hs.config.worker_app)
 
         # The scheduled call to self._expire_event. None if no call is currently
         # scheduled.
@@ -260,7 +259,6 @@ def maybe_schedule_expiry(self, event):
         Args:
             event (EventBase): The event to schedule the expiry of.
         """
-        assert not self._is_worker_app
 
         expiry_ts = event.content.get(EventContentFields.SELF_DESTRUCT_AFTER)
         if not isinstance(expiry_ts, int) or event.is_state():
@@ -488,9 +486,13 @@ def create_event(
 
                 try:
                     if "displayname" not in content:
-                        content["displayname"] = yield profile.get_displayname(target)
+                        displayname = yield profile.get_displayname(target)
+                        if displayname is not None:
+                            content["displayname"] = displayname
                     if "avatar_url" not in content:
-                        content["avatar_url"] = yield profile.get_avatar_url(target)
+                        avatar_url = yield profile.get_avatar_url(target)
+                        if avatar_url is not None:
+                            content["avatar_url"] = avatar_url
                 except Exception as e:
                     logger.info(
                         "Failed to get profile information for %r: %s", target, e
diff --git a/synapse/handlers/oidc_handler.py b/synapse/handlers/oidc_handler.py
new file mode 100644
index 000000000000..4ba8c7fda502
--- /dev/null
+++ b/synapse/handlers/oidc_handler.py
@@ -0,0 +1,1036 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Quentin Gliech
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import json
+import logging
+from typing import Dict, Generic, List, Optional, Tuple, TypeVar
+from urllib.parse import urlencode
+
+import attr
+import pymacaroons
+from authlib.common.security import generate_token
+from authlib.jose import JsonWebToken
+from authlib.oauth2.auth import ClientAuth
+from authlib.oauth2.rfc6749.parameters import prepare_grant_uri
+from authlib.oidc.core import CodeIDToken, ImplicitIDToken, UserInfo
+from authlib.oidc.discovery import OpenIDProviderMetadata, get_well_known_url
+from jinja2 import Environment, Template
+from pymacaroons.exceptions import (
+    MacaroonDeserializationException,
+    MacaroonInvalidSignatureException,
+)
+from typing_extensions import TypedDict
+
+from twisted.web.client import readBody
+
+from synapse.config import ConfigError
+from synapse.http.server import finish_request
+from synapse.http.site import SynapseRequest
+from synapse.push.mailer import load_jinja2_templates
+from synapse.server import HomeServer
+from synapse.types import UserID, map_username_to_mxid_localpart
+
+logger = logging.getLogger(__name__)
+
+SESSION_COOKIE_NAME = b"oidc_session"
+
+#: A token exchanged from the token endpoint, as per RFC6749 sec 5.1. and
+#: OpenID.Core sec 3.1.3.3.
+Token = TypedDict(
+    "Token",
+    {
+        "access_token": str,
+        "token_type": str,
+        "id_token": Optional[str],
+        "refresh_token": Optional[str],
+        "expires_in": int,
+        "scope": Optional[str],
+    },
+)
+
+#: A JWK, as per RFC7517 sec 4. The type could be more precise than that, but
+#: there is no real point of doing this in our case.
+JWK = Dict[str, str]
+
+#: A JWK Set, as per RFC7517 sec 5.
+JWKS = TypedDict("JWKS", {"keys": List[JWK]})
+
+
+class OidcError(Exception):
+    """Used to catch errors when calling the token_endpoint
+    """
+
+    def __init__(self, error, error_description=None):
+        self.error = error
+        self.error_description = error_description
+
+    def __str__(self):
+        if self.error_description:
+            return "{}: {}".format(self.error, self.error_description)
+        return self.error
+
+
+class MappingException(Exception):
+    """Used to catch errors when mapping the UserInfo object
+    """
+
+
+class OidcHandler:
+    """Handles requests related to the OpenID Connect login flow.
+    """
+
+    def __init__(self, hs: HomeServer):
+        self._callback_url = hs.config.oidc_callback_url  # type: str
+        self._scopes = hs.config.oidc_scopes  # type: List[str]
+        self._client_auth = ClientAuth(
+            hs.config.oidc_client_id,
+            hs.config.oidc_client_secret,
+            hs.config.oidc_client_auth_method,
+        )  # type: ClientAuth
+        self._client_auth_method = hs.config.oidc_client_auth_method  # type: str
+        self._subject_claim = hs.config.oidc_subject_claim
+        self._provider_metadata = OpenIDProviderMetadata(
+            issuer=hs.config.oidc_issuer,
+            authorization_endpoint=hs.config.oidc_authorization_endpoint,
+            token_endpoint=hs.config.oidc_token_endpoint,
+            userinfo_endpoint=hs.config.oidc_userinfo_endpoint,
+            jwks_uri=hs.config.oidc_jwks_uri,
+        )  # type: OpenIDProviderMetadata
+        self._provider_needs_discovery = hs.config.oidc_discover  # type: bool
+        self._user_mapping_provider = hs.config.oidc_user_mapping_provider_class(
+            hs.config.oidc_user_mapping_provider_config
+        )  # type: OidcMappingProvider
+        self._skip_verification = hs.config.oidc_skip_verification  # type: bool
+
+        self._http_client = hs.get_proxied_http_client()
+        self._auth_handler = hs.get_auth_handler()
+        self._registration_handler = hs.get_registration_handler()
+        self._datastore = hs.get_datastore()
+        self._clock = hs.get_clock()
+        self._hostname = hs.hostname  # type: str
+        self._server_name = hs.config.server_name  # type: str
+        self._macaroon_secret_key = hs.config.macaroon_secret_key
+        self._error_template = load_jinja2_templates(
+            hs.config.sso_template_dir, ["sso_error.html"]
+        )[0]
+
+        # identifier for the external_ids table
+        self._auth_provider_id = "oidc"
+
+    def _render_error(
+        self, request, error: str, error_description: Optional[str] = None
+    ) -> None:
+        """Renders the error template and respond with it.
+
+        This is used to show errors to the user. The template of this page can
+        be found under ``synapse/res/templates/sso_error.html``.
+
+        Args:
+            request: The incoming request from the browser.
+                We'll respond with an HTML page describing the error.
+            error: A technical identifier for this error. Those include
+                well-known OAuth2/OIDC error types like invalid_request or
+                access_denied.
+            error_description: A human-readable description of the error.
+        """
+        html_bytes = self._error_template.render(
+            error=error, error_description=error_description
+        ).encode("utf-8")
+
+        request.setResponseCode(400)
+        request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
+        request.setHeader(b"Content-Length", b"%i" % len(html_bytes))
+        request.write(html_bytes)
+        finish_request(request)
+
+    def _validate_metadata(self):
+        """Verifies the provider metadata.
+
+        This checks the validity of the currently loaded provider. Not
+        everything is checked, only:
+
+          - ``issuer``
+          - ``authorization_endpoint``
+          - ``token_endpoint``
+          - ``response_types_supported`` (checks if "code" is in it)
+          - ``jwks_uri``
+
+        Raises:
+            ValueError: if something in the provider is not valid
+        """
+        # Skip verification to allow non-compliant providers (e.g. issuers not running on a secure origin)
+        if self._skip_verification is True:
+            return
+
+        m = self._provider_metadata
+        m.validate_issuer()
+        m.validate_authorization_endpoint()
+        m.validate_token_endpoint()
+
+        if m.get("token_endpoint_auth_methods_supported") is not None:
+            m.validate_token_endpoint_auth_methods_supported()
+            if (
+                self._client_auth_method
+                not in m["token_endpoint_auth_methods_supported"]
+            ):
+                raise ValueError(
+                    '"{auth_method}" not in "token_endpoint_auth_methods_supported" ({supported!r})'.format(
+                        auth_method=self._client_auth_method,
+                        supported=m["token_endpoint_auth_methods_supported"],
+                    )
+                )
+
+        if m.get("response_types_supported") is not None:
+            m.validate_response_types_supported()
+
+            if "code" not in m["response_types_supported"]:
+                raise ValueError(
+                    '"code" not in "response_types_supported" (%r)'
+                    % (m["response_types_supported"],)
+                )
+
+        # If the openid scope was not requested, we need a userinfo endpoint to fetch user infos
+        if self._uses_userinfo:
+            if m.get("userinfo_endpoint") is None:
+                raise ValueError(
+                    'provider has no "userinfo_endpoint", even though it is required because the "openid" scope is not requested'
+                )
+        else:
+            # If we're not using userinfo, we need a valid jwks to validate the ID token
+            if m.get("jwks") is None:
+                if m.get("jwks_uri") is not None:
+                    m.validate_jwks_uri()
+                else:
+                    raise ValueError('"jwks_uri" must be set')
+
+    @property
+    def _uses_userinfo(self) -> bool:
+        """Returns True if the ``userinfo_endpoint`` should be used.
+
+        This is based on the requested scopes: if the scopes include
+        ``openid``, the provider should give use an ID token containing the
+        user informations. If not, we should fetch them using the
+        ``access_token`` with the ``userinfo_endpoint``.
+        """
+
+        # Maybe that should be user-configurable and not inferred?
+        return "openid" not in self._scopes
+
+    async def load_metadata(self) -> OpenIDProviderMetadata:
+        """Load and validate the provider metadata.
+
+        The values metadatas are discovered if ``oidc_config.discovery`` is
+        ``True`` and then cached.
+
+        Raises:
+            ValueError: if something in the provider is not valid
+
+        Returns:
+            The provider's metadata.
+        """
+        # If we are using the OpenID Discovery documents, it needs to be loaded once
+        # FIXME: should there be a lock here?
+        if self._provider_needs_discovery:
+            url = get_well_known_url(self._provider_metadata["issuer"], external=True)
+            metadata_response = await self._http_client.get_json(url)
+            # TODO: maybe update the other way around to let user override some values?
+            self._provider_metadata.update(metadata_response)
+            self._provider_needs_discovery = False
+
+        self._validate_metadata()
+
+        return self._provider_metadata
+
+    async def load_jwks(self, force: bool = False) -> JWKS:
+        """Load the JSON Web Key Set used to sign ID tokens.
+
+        If we're not using the ``userinfo_endpoint``, user infos are extracted
+        from the ID token, which is a JWT signed by keys given by the provider.
+        The keys are then cached.
+
+        Args:
+            force: Force reloading the keys.
+
+        Returns:
+            The key set
+
+            Looks like this::
+
+                {
+                    'keys': [
+                        {
+                            'kid': 'abcdef',
+                            'kty': 'RSA',
+                            'alg': 'RS256',
+                            'use': 'sig',
+                            'e': 'XXXX',
+                            'n': 'XXXX',
+                        }
+                    ]
+                }
+        """
+        if self._uses_userinfo:
+            # We're not using jwt signing, return an empty jwk set
+            return {"keys": []}
+
+        # First check if the JWKS are loaded in the provider metadata.
+        # It can happen either if the provider gives its JWKS in the discovery
+        # document directly or if it was already loaded once.
+        metadata = await self.load_metadata()
+        jwk_set = metadata.get("jwks")
+        if jwk_set is not None and not force:
+            return jwk_set
+
+        # Loading the JWKS using the `jwks_uri` metadata
+        uri = metadata.get("jwks_uri")
+        if not uri:
+            raise RuntimeError('Missing "jwks_uri" in metadata')
+
+        jwk_set = await self._http_client.get_json(uri)
+
+        # Caching the JWKS in the provider's metadata
+        self._provider_metadata["jwks"] = jwk_set
+        return jwk_set
+
+    async def _exchange_code(self, code: str) -> Token:
+        """Exchange an authorization code for a token.
+
+        This calls the ``token_endpoint`` with the authorization code we
+        received in the callback to exchange it for a token. The call uses the
+        ``ClientAuth`` to authenticate with the client with its ID and secret.
+
+        Args:
+            code: The authorization code we got from the callback.
+
+        Returns:
+            A dict containing various tokens.
+
+            May look like this::
+
+                {
+                    'token_type': 'bearer',
+                    'access_token': 'abcdef',
+                    'expires_in': 3599,
+                    'id_token': 'ghijkl',
+                    'refresh_token': 'mnopqr',
+                }
+
+        Raises:
+            OidcError: when the ``token_endpoint`` returned an error.
+        """
+        metadata = await self.load_metadata()
+        token_endpoint = metadata.get("token_endpoint")
+        headers = {
+            "Content-Type": "application/x-www-form-urlencoded",
+            "User-Agent": self._http_client.user_agent,
+            "Accept": "application/json",
+        }
+
+        args = {
+            "grant_type": "authorization_code",
+            "code": code,
+            "redirect_uri": self._callback_url,
+        }
+        body = urlencode(args, True)
+
+        # Fill the body/headers with credentials
+        uri, headers, body = self._client_auth.prepare(
+            method="POST", uri=token_endpoint, headers=headers, body=body
+        )
+        headers = {k: [v] for (k, v) in headers.items()}
+
+        # Do the actual request
+        # We're not using the SimpleHttpClient util methods as we don't want to
+        # check the HTTP status code and we do the body encoding ourself.
+        response = await self._http_client.request(
+            method="POST", uri=uri, data=body.encode("utf-8"), headers=headers,
+        )
+
+        # This is used in multiple error messages below
+        status = "{code} {phrase}".format(
+            code=response.code, phrase=response.phrase.decode("utf-8")
+        )
+
+        resp_body = await readBody(response)
+
+        if response.code >= 500:
+            # In case of a server error, we should first try to decode the body
+            # and check for an error field. If not, we respond with a generic
+            # error message.
+            try:
+                resp = json.loads(resp_body.decode("utf-8"))
+                error = resp["error"]
+                description = resp.get("error_description", error)
+            except (ValueError, KeyError):
+                # Catch ValueError for the JSON decoding and KeyError for the "error" field
+                error = "server_error"
+                description = (
+                    (
+                        'Authorization server responded with a "{status}" error '
+                        "while exchanging the authorization code."
+                    ).format(status=status),
+                )
+
+            raise OidcError(error, description)
+
+        # Since it is a not a 5xx code, body should be a valid JSON. It will
+        # raise if not.
+        resp = json.loads(resp_body.decode("utf-8"))
+
+        if "error" in resp:
+            error = resp["error"]
+            # In case the authorization server responded with an error field,
+            # it should be a 4xx code. If not, warn about it but don't do
+            # anything special and report the original error message.
+            if response.code < 400:
+                logger.debug(
+                    "Invalid response from the authorization server: "
+                    'responded with a "{status}" '
+                    "but body has an error field: {error!r}".format(
+                        status=status, error=resp["error"]
+                    )
+                )
+
+            description = resp.get("error_description", error)
+            raise OidcError(error, description)
+
+        # Now, this should not be an error. According to RFC6749 sec 5.1, it
+        # should be a 200 code. We're a bit more flexible than that, and will
+        # only throw on a 4xx code.
+        if response.code >= 400:
+            description = (
+                'Authorization server responded with a "{status}" error '
+                'but did not include an "error" field in its response.'.format(
+                    status=status
+                )
+            )
+            logger.warning(description)
+            # Body was still valid JSON. Might be useful to log it for debugging.
+            logger.warning("Code exchange response: {resp!r}".format(resp=resp))
+            raise OidcError("server_error", description)
+
+        return resp
+
+    async def _fetch_userinfo(self, token: Token) -> UserInfo:
+        """Fetch user informations from the ``userinfo_endpoint``.
+
+        Args:
+            token: the token given by the ``token_endpoint``.
+                Must include an ``access_token`` field.
+
+        Returns:
+            UserInfo: an object representing the user.
+        """
+        metadata = await self.load_metadata()
+
+        resp = await self._http_client.get_json(
+            metadata["userinfo_endpoint"],
+            headers={"Authorization": ["Bearer {}".format(token["access_token"])]},
+        )
+
+        return UserInfo(resp)
+
+    async def _parse_id_token(self, token: Token, nonce: str) -> UserInfo:
+        """Return an instance of UserInfo from token's ``id_token``.
+
+        Args:
+            token: the token given by the ``token_endpoint``.
+                Must include an ``id_token`` field.
+            nonce: the nonce value originally sent in the initial authorization
+                request. This value should match the one inside the token.
+
+        Returns:
+            An object representing the user.
+        """
+        metadata = await self.load_metadata()
+        claims_params = {
+            "nonce": nonce,
+            "client_id": self._client_auth.client_id,
+        }
+        if "access_token" in token:
+            # If we got an `access_token`, there should be an `at_hash` claim
+            # in the `id_token` that we can check against.
+            claims_params["access_token"] = token["access_token"]
+            claims_cls = CodeIDToken
+        else:
+            claims_cls = ImplicitIDToken
+
+        alg_values = metadata.get("id_token_signing_alg_values_supported", ["RS256"])
+
+        jwt = JsonWebToken(alg_values)
+
+        claim_options = {"iss": {"values": [metadata["issuer"]]}}
+
+        # Try to decode the keys in cache first, then retry by forcing the keys
+        # to be reloaded
+        jwk_set = await self.load_jwks()
+        try:
+            claims = jwt.decode(
+                token["id_token"],
+                key=jwk_set,
+                claims_cls=claims_cls,
+                claims_options=claim_options,
+                claims_params=claims_params,
+            )
+        except ValueError:
+            jwk_set = await self.load_jwks(force=True)  # try reloading the jwks
+            claims = jwt.decode(
+                token["id_token"],
+                key=jwk_set,
+                claims_cls=claims_cls,
+                claims_options=claim_options,
+                claims_params=claims_params,
+            )
+
+        claims.validate(leeway=120)  # allows 2 min of clock skew
+        return UserInfo(claims)
+
+    async def handle_redirect_request(
+        self,
+        request: SynapseRequest,
+        client_redirect_url: bytes,
+        ui_auth_session_id: Optional[str] = None,
+    ) -> str:
+        """Handle an incoming request to /login/sso/redirect
+
+        It returns a redirect to the authorization endpoint with a few
+        parameters:
+
+          - ``client_id``: the client ID set in ``oidc_config.client_id``
+          - ``response_type``: ``code``
+          - ``redirect_uri``: the callback URL ; ``{base url}/_synapse/oidc/callback``
+          - ``scope``: the list of scopes set in ``oidc_config.scopes``
+          - ``state``: a random string
+          - ``nonce``: a random string
+
+        In addition generating a redirect URL, we are setting a cookie with
+        a signed macaroon token containing the state, the nonce and the
+        client_redirect_url params. Those are then checked when the client
+        comes back from the provider.
+
+        Args:
+            request: the incoming request from the browser.
+                We'll respond to it with a redirect and a cookie.
+            client_redirect_url: the URL that we should redirect the client to
+                when everything is done
+            ui_auth_session_id: The session ID of the ongoing UI Auth (or
+                None if this is a login).
+
+        Returns:
+            The redirect URL to the authorization endpoint.
+
+        """
+
+        state = generate_token()
+        nonce = generate_token()
+
+        cookie = self._generate_oidc_session_token(
+            state=state,
+            nonce=nonce,
+            client_redirect_url=client_redirect_url.decode(),
+            ui_auth_session_id=ui_auth_session_id,
+        )
+        request.addCookie(
+            SESSION_COOKIE_NAME,
+            cookie,
+            path="/_synapse/oidc",
+            max_age="3600",
+            httpOnly=True,
+            sameSite="lax",
+        )
+
+        metadata = await self.load_metadata()
+        authorization_endpoint = metadata.get("authorization_endpoint")
+        return prepare_grant_uri(
+            authorization_endpoint,
+            client_id=self._client_auth.client_id,
+            response_type="code",
+            redirect_uri=self._callback_url,
+            scope=self._scopes,
+            state=state,
+            nonce=nonce,
+        )
+
+    async def handle_oidc_callback(self, request: SynapseRequest) -> None:
+        """Handle an incoming request to /_synapse/oidc/callback
+
+        Since we might want to display OIDC-related errors in a user-friendly
+        way, we don't raise SynapseError from here. Instead, we call
+        ``self._render_error`` which displays an HTML page for the error.
+
+        Most of the OpenID Connect logic happens here:
+
+          - first, we check if there was any error returned by the provider and
+            display it
+          - then we fetch the session cookie, decode and verify it
+          - the ``state`` query parameter should match with the one stored in the
+            session cookie
+          - once we known this session is legit, exchange the code with the
+            provider using the ``token_endpoint`` (see ``_exchange_code``)
+          - once we have the token, use it to either extract the UserInfo from
+            the ``id_token`` (``_parse_id_token``), or use the ``access_token``
+            to fetch UserInfo from the ``userinfo_endpoint``
+            (``_fetch_userinfo``)
+          - map those UserInfo to a Matrix user (``_map_userinfo_to_user``) and
+            finish the login
+
+        Args:
+            request: the incoming request from the browser.
+        """
+
+        # The provider might redirect with an error.
+        # In that case, just display it as-is.
+        if b"error" in request.args:
+            error = request.args[b"error"][0].decode()
+            description = request.args.get(b"error_description", [b""])[0].decode()
+
+            # Most of the errors returned by the provider could be due by
+            # either the provider misbehaving or Synapse being misconfigured.
+            # The only exception of that is "access_denied", where the user
+            # probably cancelled the login flow. In other cases, log those errors.
+            if error != "access_denied":
+                logger.error("Error from the OIDC provider: %s %s", error, description)
+
+            self._render_error(request, error, description)
+            return
+
+        # Fetch the session cookie
+        session = request.getCookie(SESSION_COOKIE_NAME)
+        if session is None:
+            logger.info("No session cookie found")
+            self._render_error(request, "missing_session", "No session cookie found")
+            return
+
+        # Remove the cookie. There is a good chance that if the callback failed
+        # once, it will fail next time and the code will already be exchanged.
+        # Removing it early avoids spamming the provider with token requests.
+        request.addCookie(
+            SESSION_COOKIE_NAME,
+            b"",
+            path="/_synapse/oidc",
+            expires="Thu, Jan 01 1970 00:00:00 UTC",
+            httpOnly=True,
+            sameSite="lax",
+        )
+
+        # Check for the state query parameter
+        if b"state" not in request.args:
+            logger.info("State parameter is missing")
+            self._render_error(request, "invalid_request", "State parameter is missing")
+            return
+
+        state = request.args[b"state"][0].decode()
+
+        # Deserialize the session token and verify it.
+        try:
+            (
+                nonce,
+                client_redirect_url,
+                ui_auth_session_id,
+            ) = self._verify_oidc_session_token(session, state)
+        except MacaroonDeserializationException as e:
+            logger.exception("Invalid session")
+            self._render_error(request, "invalid_session", str(e))
+            return
+        except MacaroonInvalidSignatureException as e:
+            logger.exception("Could not verify session")
+            self._render_error(request, "mismatching_session", str(e))
+            return
+
+        # Exchange the code with the provider
+        if b"code" not in request.args:
+            logger.info("Code parameter is missing")
+            self._render_error(request, "invalid_request", "Code parameter is missing")
+            return
+
+        logger.info("Exchanging code")
+        code = request.args[b"code"][0].decode()
+        try:
+            token = await self._exchange_code(code)
+        except OidcError as e:
+            logger.exception("Could not exchange code")
+            self._render_error(request, e.error, e.error_description)
+            return
+
+        # Now that we have a token, get the userinfo, either by decoding the
+        # `id_token` or by fetching the `userinfo_endpoint`.
+        if self._uses_userinfo:
+            logger.info("Fetching userinfo")
+            try:
+                userinfo = await self._fetch_userinfo(token)
+            except Exception as e:
+                logger.exception("Could not fetch userinfo")
+                self._render_error(request, "fetch_error", str(e))
+                return
+        else:
+            logger.info("Extracting userinfo from id_token")
+            try:
+                userinfo = await self._parse_id_token(token, nonce=nonce)
+            except Exception as e:
+                logger.exception("Invalid id_token")
+                self._render_error(request, "invalid_token", str(e))
+                return
+
+        # Call the mapper to register/login the user
+        try:
+            user_id = await self._map_userinfo_to_user(userinfo, token)
+        except MappingException as e:
+            logger.exception("Could not map user")
+            self._render_error(request, "mapping_error", str(e))
+            return
+
+        # and finally complete the login
+        if ui_auth_session_id:
+            await self._auth_handler.complete_sso_ui_auth(
+                user_id, ui_auth_session_id, request
+            )
+        else:
+            await self._auth_handler.complete_sso_login(
+                user_id, request, client_redirect_url
+            )
+
+    def _generate_oidc_session_token(
+        self,
+        state: str,
+        nonce: str,
+        client_redirect_url: str,
+        ui_auth_session_id: Optional[str],
+        duration_in_ms: int = (60 * 60 * 1000),
+    ) -> str:
+        """Generates a signed token storing data about an OIDC session.
+
+        When Synapse initiates an authorization flow, it creates a random state
+        and a random nonce. Those parameters are given to the provider and
+        should be verified when the client comes back from the provider.
+        It is also used to store the client_redirect_url, which is used to
+        complete the SSO login flow.
+
+        Args:
+            state: The ``state`` parameter passed to the OIDC provider.
+            nonce: The ``nonce`` parameter passed to the OIDC provider.
+            client_redirect_url: The URL the client gave when it initiated the
+                flow.
+            ui_auth_session_id: The session ID of the ongoing UI Auth (or
+                None if this is a login).
+            duration_in_ms: An optional duration for the token in milliseconds.
+                Defaults to an hour.
+
+        Returns:
+            A signed macaroon token with the session informations.
+        """
+        macaroon = pymacaroons.Macaroon(
+            location=self._server_name, identifier="key", key=self._macaroon_secret_key,
+        )
+        macaroon.add_first_party_caveat("gen = 1")
+        macaroon.add_first_party_caveat("type = session")
+        macaroon.add_first_party_caveat("state = %s" % (state,))
+        macaroon.add_first_party_caveat("nonce = %s" % (nonce,))
+        macaroon.add_first_party_caveat(
+            "client_redirect_url = %s" % (client_redirect_url,)
+        )
+        if ui_auth_session_id:
+            macaroon.add_first_party_caveat(
+                "ui_auth_session_id = %s" % (ui_auth_session_id,)
+            )
+        now = self._clock.time_msec()
+        expiry = now + duration_in_ms
+        macaroon.add_first_party_caveat("time < %d" % (expiry,))
+
+        return macaroon.serialize()
+
+    def _verify_oidc_session_token(
+        self, session: str, state: str
+    ) -> Tuple[str, str, Optional[str]]:
+        """Verifies and extract an OIDC session token.
+
+        This verifies that a given session token was issued by this homeserver
+        and extract the nonce and client_redirect_url caveats.
+
+        Args:
+            session: The session token to verify
+            state: The state the OIDC provider gave back
+
+        Returns:
+            The nonce, client_redirect_url, and ui_auth_session_id for this session
+        """
+        macaroon = pymacaroons.Macaroon.deserialize(session)
+
+        v = pymacaroons.Verifier()
+        v.satisfy_exact("gen = 1")
+        v.satisfy_exact("type = session")
+        v.satisfy_exact("state = %s" % (state,))
+        v.satisfy_general(lambda c: c.startswith("nonce = "))
+        v.satisfy_general(lambda c: c.startswith("client_redirect_url = "))
+        # Sometimes there's a UI auth session ID, it seems to be OK to attempt
+        # to always satisfy this.
+        v.satisfy_general(lambda c: c.startswith("ui_auth_session_id = "))
+        v.satisfy_general(self._verify_expiry)
+
+        v.verify(macaroon, self._macaroon_secret_key)
+
+        # Extract the `nonce`, `client_redirect_url`, and maybe the
+        # `ui_auth_session_id` from the token.
+        nonce = self._get_value_from_macaroon(macaroon, "nonce")
+        client_redirect_url = self._get_value_from_macaroon(
+            macaroon, "client_redirect_url"
+        )
+        try:
+            ui_auth_session_id = self._get_value_from_macaroon(
+                macaroon, "ui_auth_session_id"
+            )  # type: Optional[str]
+        except ValueError:
+            ui_auth_session_id = None
+
+        return nonce, client_redirect_url, ui_auth_session_id
+
+    def _get_value_from_macaroon(self, macaroon: pymacaroons.Macaroon, key: str) -> str:
+        """Extracts a caveat value from a macaroon token.
+
+        Args:
+            macaroon: the token
+            key: the key of the caveat to extract
+
+        Returns:
+            The extracted value
+
+        Raises:
+            Exception: if the caveat was not in the macaroon
+        """
+        prefix = key + " = "
+        for caveat in macaroon.caveats:
+            if caveat.caveat_id.startswith(prefix):
+                return caveat.caveat_id[len(prefix) :]
+        raise ValueError("No %s caveat in macaroon" % (key,))
+
+    def _verify_expiry(self, caveat: str) -> bool:
+        prefix = "time < "
+        if not caveat.startswith(prefix):
+            return False
+        expiry = int(caveat[len(prefix) :])
+        now = self._clock.time_msec()
+        return now < expiry
+
+    async def _map_userinfo_to_user(self, userinfo: UserInfo, token: Token) -> str:
+        """Maps a UserInfo object to a mxid.
+
+        UserInfo should have a claim that uniquely identifies users. This claim
+        is usually `sub`, but can be configured with `oidc_config.subject_claim`.
+        It is then used as an `external_id`.
+
+        If we don't find the user that way, we should register the user,
+        mapping the localpart and the display name from the UserInfo.
+
+        If a user already exists with the mxid we've mapped, raise an exception.
+
+        Args:
+            userinfo: an object representing the user
+            token: a dict with the tokens obtained from the provider
+
+        Raises:
+            MappingException: if there was an error while mapping some properties
+
+        Returns:
+            The mxid of the user
+        """
+        try:
+            remote_user_id = self._user_mapping_provider.get_remote_user_id(userinfo)
+        except Exception as e:
+            raise MappingException(
+                "Failed to extract subject from OIDC response: %s" % (e,)
+            )
+
+        logger.info(
+            "Looking for existing mapping for user %s:%s",
+            self._auth_provider_id,
+            remote_user_id,
+        )
+
+        registered_user_id = await self._datastore.get_user_by_external_id(
+            self._auth_provider_id, remote_user_id,
+        )
+
+        if registered_user_id is not None:
+            logger.info("Found existing mapping %s", registered_user_id)
+            return registered_user_id
+
+        try:
+            attributes = await self._user_mapping_provider.map_user_attributes(
+                userinfo, token
+            )
+        except Exception as e:
+            raise MappingException(
+                "Could not extract user attributes from OIDC response: " + str(e)
+            )
+
+        logger.debug(
+            "Retrieved user attributes from user mapping provider: %r", attributes
+        )
+
+        if not attributes["localpart"]:
+            raise MappingException("localpart is empty")
+
+        localpart = map_username_to_mxid_localpart(attributes["localpart"])
+
+        user_id = UserID(localpart, self._hostname)
+        if await self._datastore.get_users_by_id_case_insensitive(user_id.to_string()):
+            # This mxid is taken
+            raise MappingException(
+                "mxid '{}' is already taken".format(user_id.to_string())
+            )
+
+        # It's the first time this user is logging in and the mapped mxid was
+        # not taken, register the user
+        registered_user_id = await self._registration_handler.register_user(
+            localpart=localpart, default_display_name=attributes["display_name"],
+        )
+
+        await self._datastore.record_user_external_id(
+            self._auth_provider_id, remote_user_id, registered_user_id,
+        )
+        return registered_user_id
+
+
+UserAttribute = TypedDict(
+    "UserAttribute", {"localpart": str, "display_name": Optional[str]}
+)
+C = TypeVar("C")
+
+
+class OidcMappingProvider(Generic[C]):
+    """A mapping provider maps a UserInfo object to user attributes.
+
+    It should provide the API described by this class.
+    """
+
+    def __init__(self, config: C):
+        """
+        Args:
+            config: A custom config object from this module, parsed by ``parse_config()``
+        """
+
+    @staticmethod
+    def parse_config(config: dict) -> C:
+        """Parse the dict provided by the homeserver's config
+
+        Args:
+            config: A dictionary containing configuration options for this provider
+
+        Returns:
+            A custom config object for this module
+        """
+        raise NotImplementedError()
+
+    def get_remote_user_id(self, userinfo: UserInfo) -> str:
+        """Get a unique user ID for this user.
+
+        Usually, in an OIDC-compliant scenario, it should be the ``sub`` claim from the UserInfo object.
+
+        Args:
+            userinfo: An object representing the user given by the OIDC provider
+
+        Returns:
+            A unique user ID
+        """
+        raise NotImplementedError()
+
+    async def map_user_attributes(
+        self, userinfo: UserInfo, token: Token
+    ) -> UserAttribute:
+        """Map a ``UserInfo`` objects into user attributes.
+
+        Args:
+            userinfo: An object representing the user given by the OIDC provider
+            token: A dict with the tokens returned by the provider
+
+        Returns:
+            A dict containing the ``localpart`` and (optionally) the ``display_name``
+        """
+        raise NotImplementedError()
+
+
+# Used to clear out "None" values in templates
+def jinja_finalize(thing):
+    return thing if thing is not None else ""
+
+
+env = Environment(finalize=jinja_finalize)
+
+
+@attr.s
+class JinjaOidcMappingConfig:
+    subject_claim = attr.ib()  # type: str
+    localpart_template = attr.ib()  # type: Template
+    display_name_template = attr.ib()  # type: Optional[Template]
+
+
+class JinjaOidcMappingProvider(OidcMappingProvider[JinjaOidcMappingConfig]):
+    """An implementation of a mapping provider based on Jinja templates.
+
+    This is the default mapping provider.
+    """
+
+    def __init__(self, config: JinjaOidcMappingConfig):
+        self._config = config
+
+    @staticmethod
+    def parse_config(config: dict) -> JinjaOidcMappingConfig:
+        subject_claim = config.get("subject_claim", "sub")
+
+        if "localpart_template" not in config:
+            raise ConfigError(
+                "missing key: oidc_config.user_mapping_provider.config.localpart_template"
+            )
+
+        try:
+            localpart_template = env.from_string(config["localpart_template"])
+        except Exception as e:
+            raise ConfigError(
+                "invalid jinja template for oidc_config.user_mapping_provider.config.localpart_template: %r"
+                % (e,)
+            )
+
+        display_name_template = None  # type: Optional[Template]
+        if "display_name_template" in config:
+            try:
+                display_name_template = env.from_string(config["display_name_template"])
+            except Exception as e:
+                raise ConfigError(
+                    "invalid jinja template for oidc_config.user_mapping_provider.config.display_name_template: %r"
+                    % (e,)
+                )
+
+        return JinjaOidcMappingConfig(
+            subject_claim=subject_claim,
+            localpart_template=localpart_template,
+            display_name_template=display_name_template,
+        )
+
+    def get_remote_user_id(self, userinfo: UserInfo) -> str:
+        return userinfo[self._config.subject_claim]
+
+    async def map_user_attributes(
+        self, userinfo: UserInfo, token: Token
+    ) -> UserAttribute:
+        localpart = self._config.localpart_template.render(user=userinfo).strip()
+
+        display_name = None  # type: Optional[str]
+        if self._config.display_name_template is not None:
+            display_name = self._config.display_name_template.render(
+                user=userinfo
+            ).strip()
+
+            if display_name == "":
+                display_name = None
+
+        return UserAttribute(localpart=localpart, display_name=display_name)
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index 5cbefae1777a..9ea11c0754df 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -204,6 +204,7 @@ def __init__(self, hs: "synapse.server.HomeServer"):
         self.notifier = hs.get_notifier()
         self.federation = hs.get_federation_sender()
         self.state = hs.get_state_handler()
+        self._presence_enabled = hs.config.use_presence
 
         federation_registry = hs.get_federation_registry()
 
@@ -676,13 +677,14 @@ def _push_to_remotes(self, states):
     async def incoming_presence(self, origin, content):
         """Called when we receive a `m.presence` EDU from a remote server.
         """
+        if not self._presence_enabled:
+            return
+
         now = self.clock.time_msec()
         updates = []
         for push in content.get("push", []):
             # A "push" contains a list of presence that we are probably interested
             # in.
-            # TODO: Actually check if we're interested, rather than blindly
-            # accepting presence updates.
             user_id = push.get("user_id", None)
             if not user_id:
                 logger.info(
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index da12df7f535e..73f9eeb39939 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -25,8 +25,6 @@
 
 from six import iteritems, string_types
 
-from twisted.internet import defer
-
 from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
 from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion
@@ -103,8 +101,7 @@ def __init__(self, hs):
 
         self.third_party_event_rules = hs.get_third_party_event_rules()
 
-    @defer.inlineCallbacks
-    def upgrade_room(
+    async def upgrade_room(
         self, requester: Requester, old_room_id: str, new_version: RoomVersion
     ):
         """Replace a room with a new room with a different version
@@ -117,7 +114,7 @@ def upgrade_room(
         Returns:
             Deferred[unicode]: the new room id
         """
-        yield self.ratelimit(requester)
+        await self.ratelimit(requester)
 
         user_id = requester.user.to_string()
 
@@ -138,7 +135,7 @@ def upgrade_room(
         # If this user has sent multiple upgrade requests for the same room
         # and one of them is not complete yet, cache the response and
         # return it to all subsequent requests
-        ret = yield self._upgrade_response_cache.wrap(
+        ret = await self._upgrade_response_cache.wrap(
             (old_room_id, user_id),
             self._upgrade_room,
             requester,
@@ -856,8 +853,7 @@ async def send(etype, content, **kwargs):
         for (etype, state_key), content in initial_state.items():
             await send(etype=etype, state_key=state_key, content=content)
 
-    @defer.inlineCallbacks
-    def _generate_room_id(
+    async def _generate_room_id(
         self, creator_id: str, is_public: str, room_version: RoomVersion,
     ):
         # autogen room IDs and try to create it. We may clash, so just
@@ -869,7 +865,7 @@ def _generate_room_id(
                 gen_room_id = RoomID(random_string, self.hs.hostname).to_string()
                 if isinstance(gen_room_id, bytes):
                     gen_room_id = gen_room_id.decode("utf-8")
-                yield self.store.store_room(
+                await self.store.store_room(
                     room_id=gen_room_id,
                     room_creator_user_id=creator_id,
                     is_public=is_public,
@@ -888,8 +884,7 @@ def __init__(self, hs):
         self.storage = hs.get_storage()
         self.state_store = self.storage.state
 
-    @defer.inlineCallbacks
-    def get_event_context(self, user, room_id, event_id, limit, event_filter):
+    async def get_event_context(self, user, room_id, event_id, limit, event_filter):
         """Retrieves events, pagination tokens and state around a given event
         in a room.
 
@@ -908,7 +903,7 @@ def get_event_context(self, user, room_id, event_id, limit, event_filter):
         before_limit = math.floor(limit / 2.0)
         after_limit = limit - before_limit
 
-        users = yield self.store.get_users_in_room(room_id)
+        users = await self.store.get_users_in_room(room_id)
         is_peeking = user.to_string() not in users
 
         def filter_evts(events):
@@ -916,17 +911,17 @@ def filter_evts(events):
                 self.storage, user.to_string(), events, is_peeking=is_peeking
             )
 
-        event = yield self.store.get_event(
+        event = await self.store.get_event(
             event_id, get_prev_content=True, allow_none=True
         )
         if not event:
             return None
 
-        filtered = yield (filter_evts([event]))
+        filtered = await filter_evts([event])
         if not filtered:
             raise AuthError(403, "You don't have permission to access that event.")
 
-        results = yield self.store.get_events_around(
+        results = await self.store.get_events_around(
             room_id, event_id, before_limit, after_limit, event_filter
         )
 
@@ -934,8 +929,8 @@ def filter_evts(events):
             results["events_before"] = event_filter.filter(results["events_before"])
             results["events_after"] = event_filter.filter(results["events_after"])
 
-        results["events_before"] = yield filter_evts(results["events_before"])
-        results["events_after"] = yield filter_evts(results["events_after"])
+        results["events_before"] = await filter_evts(results["events_before"])
+        results["events_after"] = await filter_evts(results["events_after"])
         # filter_evts can return a pruned event in case the user is allowed to see that
         # there's something there but not see the content, so use the event that's in
         # `filtered` rather than the event we retrieved from the datastore.
@@ -962,7 +957,7 @@ def filter_evts(events):
         # first? Shouldn't we be consistent with /sync?
         # https://github.com/matrix-org/matrix-doc/issues/687
 
-        state = yield self.state_store.get_state_for_events(
+        state = await self.state_store.get_state_for_events(
             [last_event_id], state_filter=state_filter
         )
 
@@ -970,7 +965,7 @@ def filter_evts(events):
         if event_filter:
             state_events = event_filter.filter(state_events)
 
-        results["state"] = yield filter_evts(state_events)
+        results["state"] = await filter_evts(state_events)
 
         # We use a dummy token here as we only care about the room portion of
         # the token, which we replace.
@@ -989,13 +984,12 @@ class RoomEventSource(object):
     def __init__(self, hs):
         self.store = hs.get_datastore()
 
-    @defer.inlineCallbacks
-    def get_new_events(
+    async def get_new_events(
         self, user, from_key, limit, room_ids, is_guest, explicit_room_id=None
     ):
         # We just ignore the key for now.
 
-        to_key = yield self.get_current_key()
+        to_key = await self.get_current_key()
 
         from_token = RoomStreamToken.parse(from_key)
         if from_token.topological:
@@ -1008,11 +1002,11 @@ def get_new_events(
             # See https://github.com/matrix-org/matrix-doc/issues/1144
             raise NotImplementedError()
         else:
-            room_events = yield self.store.get_membership_changes_for_user(
+            room_events = await self.store.get_membership_changes_for_user(
                 user.to_string(), from_key, to_key
             )
 
-            room_to_events = yield self.store.get_room_events_stream_for_rooms(
+            room_to_events = await self.store.get_room_events_stream_for_rooms(
                 room_ids=room_ids,
                 from_key=from_key,
                 to_key=to_key,
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 79d69f9b3b0d..619252b761ad 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -17,15 +17,16 @@
 
 import abc
 import logging
+from typing import Dict, Iterable, List, Optional, Tuple, Union
 
 from six.moves import http_client
 
-from twisted.internet import defer
-
 from synapse import types
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import AuthError, Codes, SynapseError
-from synapse.types import Collection, RoomID, UserID
+from synapse.events import EventBase
+from synapse.events.snapshot import EventContext
+from synapse.types import Collection, Requester, RoomAlias, RoomID, UserID
 from synapse.util.async_helpers import Linearizer
 from synapse.util.distributor import user_joined_room, user_left_room
 
@@ -77,84 +78,84 @@ def __init__(self, hs):
         self.base_handler = BaseHandler(hs)
 
     @abc.abstractmethod
-    def _remote_join(self, requester, remote_room_hosts, room_id, user, content):
+    async def _remote_join(
+        self,
+        requester: Requester,
+        remote_room_hosts: List[str],
+        room_id: str,
+        user: UserID,
+        content: dict,
+    ) -> Optional[dict]:
         """Try and join a room that this server is not in
 
         Args:
-            requester (Requester)
-            remote_room_hosts (list[str]): List of servers that can be used
-                to join via.
-            room_id (str): Room that we are trying to join
-            user (UserID): User who is trying to join
-            content (dict): A dict that should be used as the content of the
-                join event.
-
-        Returns:
-            Deferred
+            requester
+            remote_room_hosts: List of servers that can be used to join via.
+            room_id: Room that we are trying to join
+            user: User who is trying to join
+            content: A dict that should be used as the content of the join event.
         """
         raise NotImplementedError()
 
     @abc.abstractmethod
-    def _remote_reject_invite(
-        self, requester, remote_room_hosts, room_id, target, content
-    ):
+    async def _remote_reject_invite(
+        self,
+        requester: Requester,
+        remote_room_hosts: List[str],
+        room_id: str,
+        target: UserID,
+        content: dict,
+    ) -> dict:
         """Attempt to reject an invite for a room this server is not in. If we
         fail to do so we locally mark the invite as rejected.
 
         Args:
-            requester (Requester)
-            remote_room_hosts (list[str]): List of servers to use to try and
-                reject invite
-            room_id (str)
-            target (UserID): The user rejecting the invite
-            content (dict): The content for the rejection event
+            requester
+            remote_room_hosts: List of servers to use to try and reject invite
+            room_id
+            target: The user rejecting the invite
+            content: The content for the rejection event
 
         Returns:
-            Deferred[dict]: A dictionary to be returned to the client, may
+            A dictionary to be returned to the client, may
             include event_id etc, or nothing if we locally rejected
         """
         raise NotImplementedError()
 
     @abc.abstractmethod
-    def _user_joined_room(self, target, room_id):
+    async def _user_joined_room(self, target: UserID, room_id: str) -> None:
         """Notifies distributor on master process that the user has joined the
         room.
 
         Args:
-            target (UserID)
-            room_id (str)
-
-        Returns:
-            Deferred|None
+            target
+            room_id
         """
         raise NotImplementedError()
 
     @abc.abstractmethod
-    def _user_left_room(self, target, room_id):
+    async def _user_left_room(self, target: UserID, room_id: str) -> None:
         """Notifies distributor on master process that the user has left the
         room.
 
         Args:
-            target (UserID)
-            room_id (str)
-
-        Returns:
-            Deferred|None
+            target
+            room_id
         """
         raise NotImplementedError()
 
     async def _local_membership_update(
         self,
-        requester,
-        target,
-        room_id,
-        membership,
+        requester: Requester,
+        target: UserID,
+        room_id: str,
+        membership: str,
         prev_event_ids: Collection[str],
-        txn_id=None,
-        ratelimit=True,
-        content=None,
-        require_consent=True,
-    ):
+        txn_id: Optional[str] = None,
+        ratelimit: bool = True,
+        content: Optional[dict] = None,
+        require_consent: bool = True,
+    ) -> EventBase:
         user_id = target.to_string()
 
         if content is None:
@@ -215,20 +216,18 @@ async def _local_membership_update(
 
         return event
 
-    @defer.inlineCallbacks
-    def copy_room_tags_and_direct_to_room(self, old_room_id, new_room_id, user_id):
+    async def copy_room_tags_and_direct_to_room(
+        self, old_room_id, new_room_id, user_id
+    ) -> None:
         """Copies the tags and direct room state from one room to another.
 
         Args:
-            old_room_id (str)
-            new_room_id (str)
-            user_id (str)
-
-        Returns:
-            Deferred[None]
+            old_room_id: The room ID of the old room.
+            new_room_id: The room ID of the new room.
+            user_id: The user's ID.
         """
         # Retrieve user account data for predecessor room
-        user_account_data, _ = yield self.store.get_account_data_for_user(user_id)
+        user_account_data, _ = await self.store.get_account_data_for_user(user_id)
 
         # Copy direct message state if applicable
         direct_rooms = user_account_data.get("m.direct", {})
@@ -241,31 +240,31 @@ def copy_room_tags_and_direct_to_room(self, old_room_id, new_room_id, user_id):
                     direct_rooms[key].append(new_room_id)
 
                     # Save back to user's m.direct account data
-                    yield self.store.add_account_data_for_user(
+                    await self.store.add_account_data_for_user(
                         user_id, "m.direct", direct_rooms
                     )
                     break
 
         # Copy room tags if applicable
-        room_tags = yield self.store.get_tags_for_room(user_id, old_room_id)
+        room_tags = await self.store.get_tags_for_room(user_id, old_room_id)
 
         # Copy each room tag to the new room
         for tag, tag_content in room_tags.items():
-            yield self.store.add_tag_to_room(user_id, new_room_id, tag, tag_content)
+            await self.store.add_tag_to_room(user_id, new_room_id, tag, tag_content)
 
     async def update_membership(
         self,
-        requester,
-        target,
-        room_id,
-        action,
-        txn_id=None,
-        remote_room_hosts=None,
-        third_party_signed=None,
-        ratelimit=True,
-        content=None,
-        require_consent=True,
-    ):
+        requester: Requester,
+        target: UserID,
+        room_id: str,
+        action: str,
+        txn_id: Optional[str] = None,
+        remote_room_hosts: Optional[List[str]] = None,
+        third_party_signed: Optional[dict] = None,
+        ratelimit: bool = True,
+        content: Optional[dict] = None,
+        require_consent: bool = True,
+    ) -> Union[EventBase, Optional[dict]]:
         key = (room_id,)
 
         as_id = object()
@@ -305,17 +304,17 @@ async def update_membership(
 
     async def _update_membership(
         self,
-        requester,
-        target,
-        room_id,
-        action,
-        txn_id=None,
-        remote_room_hosts=None,
-        third_party_signed=None,
-        ratelimit=True,
-        content=None,
-        require_consent=True,
-    ):
+        requester: Requester,
+        target: UserID,
+        room_id: str,
+        action: str,
+        txn_id: Optional[str] = None,
+        remote_room_hosts: Optional[List[str]] = None,
+        third_party_signed: Optional[dict] = None,
+        ratelimit: bool = True,
+        content: Optional[dict] = None,
+        require_consent: bool = True,
+    ) -> Union[EventBase, Optional[dict]]:
         content_specified = bool(content)
         if content is None:
             content = {}
@@ -489,12 +488,11 @@ async def _update_membership(
                 else:
                     # send the rejection to the inviter's HS.
                     remote_room_hosts = remote_room_hosts + [inviter.domain]
-                    res = await self._remote_reject_invite(
+                    return await self._remote_reject_invite(
                         requester, remote_room_hosts, room_id, target, content,
                     )
-                    return res
 
-        res = await self._local_membership_update(
+        return await self._local_membership_update(
             requester=requester,
             target=target,
             room_id=room_id,
@@ -505,10 +503,10 @@ async def _update_membership(
             content=content,
             require_consent=require_consent,
         )
-        return res
 
-    @defer.inlineCallbacks
-    def transfer_room_state_on_room_upgrade(self, old_room_id, room_id):
+    async def transfer_room_state_on_room_upgrade(
+        self, old_room_id: str, room_id: str
+    ) -> None:
         """Upon our server becoming aware of an upgraded room, either by upgrading a room
         ourselves or joining one, we can transfer over information from the previous room.
 
@@ -516,50 +514,44 @@ def transfer_room_state_on_room_upgrade(self, old_room_id, room_id):
         well as migrating the room directory state.
 
         Args:
-            old_room_id (str): The ID of the old room
-
-            room_id (str): The ID of the new room
-
-        Returns:
-            Deferred
+            old_room_id: The ID of the old room
+            room_id: The ID of the new room
         """
         logger.info("Transferring room state from %s to %s", old_room_id, room_id)
 
         # Find all local users that were in the old room and copy over each user's state
-        users = yield self.store.get_users_in_room(old_room_id)
-        yield self.copy_user_state_on_room_upgrade(old_room_id, room_id, users)
+        users = await self.store.get_users_in_room(old_room_id)
+        await self.copy_user_state_on_room_upgrade(old_room_id, room_id, users)
 
         # Add new room to the room directory if the old room was there
         # Remove old room from the room directory
-        old_room = yield self.store.get_room(old_room_id)
+        old_room = await self.store.get_room(old_room_id)
         if old_room and old_room["is_public"]:
-            yield self.store.set_room_is_public(old_room_id, False)
-            yield self.store.set_room_is_public(room_id, True)
+            await self.store.set_room_is_public(old_room_id, False)
+            await self.store.set_room_is_public(room_id, True)
 
         # Transfer alias mappings in the room directory
-        yield self.store.update_aliases_for_room(old_room_id, room_id)
+        await self.store.update_aliases_for_room(old_room_id, room_id)
 
         # Check if any groups we own contain the predecessor room
-        local_group_ids = yield self.store.get_local_groups_for_room(old_room_id)
+        local_group_ids = await self.store.get_local_groups_for_room(old_room_id)
         for group_id in local_group_ids:
             # Add new the new room to those groups
-            yield self.store.add_room_to_group(group_id, room_id, old_room["is_public"])
+            await self.store.add_room_to_group(group_id, room_id, old_room["is_public"])
 
             # Remove the old room from those groups
-            yield self.store.remove_room_from_group(group_id, old_room_id)
+            await self.store.remove_room_from_group(group_id, old_room_id)
 
-    @defer.inlineCallbacks
-    def copy_user_state_on_room_upgrade(self, old_room_id, new_room_id, user_ids):
+    async def copy_user_state_on_room_upgrade(
+        self, old_room_id: str, new_room_id: str, user_ids: Iterable[str]
+    ) -> None:
         """Copy user-specific information when they join a new room when that new room is the
         result of a room upgrade
 
         Args:
-            old_room_id (str): The ID of upgraded room
-            new_room_id (str): The ID of the new room
-            user_ids (Iterable[str]): User IDs to copy state for
-
-        Returns:
-            Deferred
+            old_room_id: The ID of upgraded room
+            new_room_id: The ID of the new room
+            user_ids: User IDs to copy state for
         """
 
         logger.debug(
@@ -572,11 +564,11 @@ def copy_user_state_on_room_upgrade(self, old_room_id, new_room_id, user_ids):
         for user_id in user_ids:
             try:
                 # It is an upgraded room. Copy over old tags
-                yield self.copy_room_tags_and_direct_to_room(
+                await self.copy_room_tags_and_direct_to_room(
                     old_room_id, new_room_id, user_id
                 )
                 # Copy over push rules
-                yield self.store.copy_push_rules_from_room_to_room_for_user(
+                await self.store.copy_push_rules_from_room_to_room_for_user(
                     old_room_id, new_room_id, user_id
                 )
             except Exception:
@@ -589,17 +581,23 @@ def copy_user_state_on_room_upgrade(self, old_room_id, new_room_id, user_ids):
                 )
                 continue
 
-    async def send_membership_event(self, requester, event, context, ratelimit=True):
+    async def send_membership_event(
+        self,
+        requester: Requester,
+        event: EventBase,
+        context: EventContext,
+        ratelimit: bool = True,
+    ):
         """
         Change the membership status of a user in a room.
 
         Args:
-            requester (Requester): The local user who requested the membership
+            requester: The local user who requested the membership
                 event. If None, certain checks, like whether this homeserver can
                 act as the sender, will be skipped.
-            event (SynapseEvent): The membership event.
+            event: The membership event.
             context: The context of the event.
-            ratelimit (bool): Whether to rate limit this request.
+            ratelimit: Whether to rate limit this request.
         Raises:
             SynapseError if there was a problem changing the membership.
         """
@@ -659,8 +657,9 @@ async def send_membership_event(self, requester, event, context, ratelimit=True)
                 if prev_member_event.membership == Membership.JOIN:
                     await self._user_left_room(target_user, room_id)
 
-    @defer.inlineCallbacks
-    def _can_guest_join(self, current_state_ids):
+    async def _can_guest_join(
+        self, current_state_ids: Dict[Tuple[str, str], str]
+    ) -> bool:
         """
         Returns whether a guest can join a room based on its current state.
         """
@@ -668,7 +667,7 @@ def _can_guest_join(self, current_state_ids):
         if not guest_access_id:
             return False
 
-        guest_access = yield self.store.get_event(guest_access_id)
+        guest_access = await self.store.get_event(guest_access_id)
 
         return (
             guest_access
@@ -677,13 +676,14 @@ def _can_guest_join(self, current_state_ids):
             and guest_access.content["guest_access"] == "can_join"
         )
 
-    @defer.inlineCallbacks
-    def lookup_room_alias(self, room_alias):
+    async def lookup_room_alias(
+        self, room_alias: RoomAlias
+    ) -> Tuple[RoomID, List[str]]:
         """
         Get the room ID associated with a room alias.
 
         Args:
-            room_alias (RoomAlias): The alias to look up.
+            room_alias: The alias to look up.
         Returns:
             A tuple of:
                 The room ID as a RoomID object.
@@ -692,7 +692,7 @@ def lookup_room_alias(self, room_alias):
             SynapseError if room alias could not be found.
         """
         directory_handler = self.directory_handler
-        mapping = yield directory_handler.get_association(room_alias)
+        mapping = await directory_handler.get_association(room_alias)
 
         if not mapping:
             raise SynapseError(404, "No such room alias")
@@ -707,25 +707,25 @@ def lookup_room_alias(self, room_alias):
 
         return RoomID.from_string(room_id), servers
 
-    @defer.inlineCallbacks
-    def _get_inviter(self, user_id, room_id):
-        invite = yield self.store.get_invite_for_local_user_in_room(
+    async def _get_inviter(self, user_id: str, room_id: str) -> Optional[UserID]:
+        invite = await self.store.get_invite_for_local_user_in_room(
             user_id=user_id, room_id=room_id
         )
         if invite:
             return UserID.from_string(invite.sender)
+        return None
 
     async def do_3pid_invite(
         self,
-        room_id,
-        inviter,
-        medium,
-        address,
-        id_server,
-        requester,
-        txn_id,
-        id_access_token=None,
-    ):
+        room_id: str,
+        inviter: UserID,
+        medium: str,
+        address: str,
+        id_server: str,
+        requester: Requester,
+        txn_id: Optional[str],
+        id_access_token: Optional[str] = None,
+    ) -> None:
         if self.config.block_non_admin_invites:
             is_requester_admin = await self.auth.is_server_admin(requester.user)
             if not is_requester_admin:
@@ -774,15 +774,15 @@ async def do_3pid_invite(
 
     async def _make_and_store_3pid_invite(
         self,
-        requester,
-        id_server,
-        medium,
-        address,
-        room_id,
-        user,
-        txn_id,
-        id_access_token=None,
-    ):
+        requester: Requester,
+        id_server: str,
+        medium: str,
+        address: str,
+        room_id: str,
+        user: UserID,
+        txn_id: Optional[str],
+        id_access_token: Optional[str] = None,
+    ) -> None:
         room_state = await self.state_handler.get_current_state(room_id)
 
         inviter_display_name = ""
@@ -856,8 +856,9 @@ async def _make_and_store_3pid_invite(
             txn_id=txn_id,
         )
 
-    @defer.inlineCallbacks
-    def _is_host_in_room(self, current_state_ids):
+    async def _is_host_in_room(
+        self, current_state_ids: Dict[Tuple[str, str], str]
+    ) -> bool:
         # Have we just created the room, and is this about to be the very
         # first member event?
         create_event_id = current_state_ids.get(("m.room.create", ""))
@@ -870,7 +871,7 @@ def _is_host_in_room(self, current_state_ids):
                 continue
 
             event_id = current_state_ids[(etype, state_key)]
-            event = yield self.store.get_event(event_id, allow_none=True)
+            event = await self.store.get_event(event_id, allow_none=True)
             if not event:
                 continue
 
@@ -879,11 +880,10 @@ def _is_host_in_room(self, current_state_ids):
 
         return False
 
-    @defer.inlineCallbacks
-    def _is_server_notice_room(self, room_id):
+    async def _is_server_notice_room(self, room_id: str) -> bool:
         if self._server_notices_mxid is None:
             return False
-        user_ids = yield self.store.get_users_in_room(room_id)
+        user_ids = await self.store.get_users_in_room(room_id)
         return self._server_notices_mxid in user_ids
 
 
@@ -895,20 +895,21 @@ def __init__(self, hs):
         self.distributor.declare("user_joined_room")
         self.distributor.declare("user_left_room")
 
-    @defer.inlineCallbacks
-    def _is_remote_room_too_complex(self, room_id, remote_room_hosts):
+    async def _is_remote_room_too_complex(
+        self, room_id: str, remote_room_hosts: List[str]
+    ) -> Optional[bool]:
         """
         Check if complexity of a remote room is too great.
 
         Args:
-            room_id (str)
-            remote_room_hosts (list[str])
+            room_id
+            remote_room_hosts
 
         Returns: bool of whether the complexity is too great, or None
             if unable to be fetched
         """
         max_complexity = self.hs.config.limit_remote_rooms.complexity
-        complexity = yield self.federation_handler.get_room_complexity(
+        complexity = await self.federation_handler.get_room_complexity(
             remote_room_hosts, room_id
         )
 
@@ -916,22 +917,26 @@ def _is_remote_room_too_complex(self, room_id, remote_room_hosts):
             return complexity["v1"] > max_complexity
         return None
 
-    @defer.inlineCallbacks
-    def _is_local_room_too_complex(self, room_id):
+    async def _is_local_room_too_complex(self, room_id: str) -> bool:
         """
         Check if the complexity of a local room is too great.
 
         Args:
-            room_id (str)
-
-        Returns: bool
+            room_id: The room ID to check for complexity.
         """
         max_complexity = self.hs.config.limit_remote_rooms.complexity
-        complexity = yield self.store.get_room_complexity(room_id)
+        complexity = await self.store.get_room_complexity(room_id)
 
         return complexity["v1"] > max_complexity
 
-    async def _remote_join(self, requester, remote_room_hosts, room_id, user, content):
+    async def _remote_join(
+        self,
+        requester: Requester,
+        remote_room_hosts: List[str],
+        room_id: str,
+        user: UserID,
+        content: dict,
+    ) -> None:
         """Implements RoomMemberHandler._remote_join
         """
         # filter ourselves out of remote_room_hosts: do_invite_join ignores it
@@ -990,18 +995,20 @@ async def _remote_join(self, requester, remote_room_hosts, room_id, user, conten
                 errcode=Codes.RESOURCE_LIMIT_EXCEEDED,
             )
 
-    @defer.inlineCallbacks
-    def _remote_reject_invite(
-        self, requester, remote_room_hosts, room_id, target, content
-    ):
+    async def _remote_reject_invite(
+        self,
+        requester: Requester,
+        remote_room_hosts: List[str],
+        room_id: str,
+        target: UserID,
+        content: dict,
+    ) -> dict:
         """Implements RoomMemberHandler._remote_reject_invite
         """
         fed_handler = self.federation_handler
         try:
-            ret = yield defer.ensureDeferred(
-                fed_handler.do_remotely_reject_invite(
-                    remote_room_hosts, room_id, target.to_string(), content=content,
-                )
+            ret = await fed_handler.do_remotely_reject_invite(
+                remote_room_hosts, room_id, target.to_string(), content=content,
             )
             return ret
         except Exception as e:
@@ -1013,24 +1020,23 @@ def _remote_reject_invite(
             #
             logger.warning("Failed to reject invite: %s", e)
 
-            yield self.store.locally_reject_invite(target.to_string(), room_id)
+            await self.store.locally_reject_invite(target.to_string(), room_id)
             return {}
 
-    def _user_joined_room(self, target, room_id):
+    async def _user_joined_room(self, target: UserID, room_id: str) -> None:
         """Implements RoomMemberHandler._user_joined_room
         """
-        return defer.succeed(user_joined_room(self.distributor, target, room_id))
+        user_joined_room(self.distributor, target, room_id)
 
-    def _user_left_room(self, target, room_id):
+    async def _user_left_room(self, target: UserID, room_id: str) -> None:
         """Implements RoomMemberHandler._user_left_room
         """
-        return defer.succeed(user_left_room(self.distributor, target, room_id))
+        user_left_room(self.distributor, target, room_id)
 
-    @defer.inlineCallbacks
-    def forget(self, user, room_id):
+    async def forget(self, user: UserID, room_id: str) -> None:
         user_id = user.to_string()
 
-        member = yield self.state_handler.get_current_state(
+        member = await self.state_handler.get_current_state(
             room_id=room_id, event_type=EventTypes.Member, state_key=user_id
         )
         membership = member.membership if member else None
@@ -1042,4 +1048,4 @@ def forget(self, user, room_id):
             raise SynapseError(400, "User %s in room %s" % (user_id, room_id))
 
         if membership:
-            yield self.store.forget(user_id, room_id)
+            await self.store.forget(user_id, room_id)
diff --git a/synapse/handlers/room_member_worker.py b/synapse/handlers/room_member_worker.py
index 69be86893bc4..5c776cc0be0d 100644
--- a/synapse/handlers/room_member_worker.py
+++ b/synapse/handlers/room_member_worker.py
@@ -14,8 +14,7 @@
 # limitations under the License.
 
 import logging
-
-from twisted.internet import defer
+from typing import List, Optional
 
 from synapse.api.errors import SynapseError
 from synapse.handlers.room_member import RoomMemberHandler
@@ -24,6 +23,7 @@
     ReplicationRemoteRejectInviteRestServlet as ReplRejectInvite,
     ReplicationUserJoinedLeftRoomRestServlet as ReplJoinedLeft,
 )
+from synapse.types import Requester, UserID
 
 logger = logging.getLogger(__name__)
 
@@ -36,14 +36,20 @@ def __init__(self, hs):
         self._remote_reject_client = ReplRejectInvite.make_client(hs)
         self._notify_change_client = ReplJoinedLeft.make_client(hs)
 
-    @defer.inlineCallbacks
-    def _remote_join(self, requester, remote_room_hosts, room_id, user, content):
+    async def _remote_join(
+        self,
+        requester: Requester,
+        remote_room_hosts: List[str],
+        room_id: str,
+        user: UserID,
+        content: dict,
+    ) -> Optional[dict]:
         """Implements RoomMemberHandler._remote_join
         """
         if len(remote_room_hosts) == 0:
             raise SynapseError(404, "No known servers")
 
-        ret = yield self._remote_join_client(
+        ret = await self._remote_join_client(
             requester=requester,
             remote_room_hosts=remote_room_hosts,
             room_id=room_id,
@@ -51,16 +57,21 @@ def _remote_join(self, requester, remote_room_hosts, room_id, user, content):
             content=content,
         )
 
-        yield self._user_joined_room(user, room_id)
+        await self._user_joined_room(user, room_id)
 
         return ret
 
-    def _remote_reject_invite(
-        self, requester, remote_room_hosts, room_id, target, content
-    ):
+    async def _remote_reject_invite(
+        self,
+        requester: Requester,
+        remote_room_hosts: List[str],
+        room_id: str,
+        target: UserID,
+        content: dict,
+    ) -> dict:
         """Implements RoomMemberHandler._remote_reject_invite
         """
-        return self._remote_reject_client(
+        return await self._remote_reject_client(
             requester=requester,
             remote_room_hosts=remote_room_hosts,
             room_id=room_id,
@@ -68,16 +79,16 @@ def _remote_reject_invite(
             content=content,
         )
 
-    def _user_joined_room(self, target, room_id):
+    async def _user_joined_room(self, target: UserID, room_id: str) -> None:
         """Implements RoomMemberHandler._user_joined_room
         """
-        return self._notify_change_client(
+        await self._notify_change_client(
             user_id=target.to_string(), room_id=room_id, change="joined"
         )
 
-    def _user_left_room(self, target, room_id):
+    async def _user_left_room(self, target: UserID, room_id: str) -> None:
         """Implements RoomMemberHandler._user_left_room
         """
-        return self._notify_change_client(
+        await self._notify_change_client(
             user_id=target.to_string(), room_id=room_id, change="left"
         )
diff --git a/synapse/handlers/saml_handler.py b/synapse/handlers/saml_handler.py
index 96f2dd36ad20..e7015c704fa2 100644
--- a/synapse/handlers/saml_handler.py
+++ b/synapse/handlers/saml_handler.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 import logging
 import re
-from typing import Optional, Tuple
+from typing import Callable, Dict, Optional, Set, Tuple
 
 import attr
 import saml2
@@ -25,6 +25,7 @@
 from synapse.config import ConfigError
 from synapse.http.server import finish_request
 from synapse.http.servlet import parse_string
+from synapse.http.site import SynapseRequest
 from synapse.module_api import ModuleApi
 from synapse.module_api.errors import RedirectException
 from synapse.types import (
@@ -81,17 +82,19 @@ def __init__(self, hs):
 
         self._error_html_content = hs.config.saml2_error_html_content
 
-    def handle_redirect_request(self, client_redirect_url, ui_auth_session_id=None):
+    def handle_redirect_request(
+        self, client_redirect_url: bytes, ui_auth_session_id: Optional[str] = None
+    ) -> bytes:
         """Handle an incoming request to /login/sso/redirect
 
         Args:
-            client_redirect_url (bytes): the URL that we should redirect the
+            client_redirect_url: the URL that we should redirect the
                 client to when everything is done
-            ui_auth_session_id (Optional[str]): The session ID of the ongoing UI Auth (or
+            ui_auth_session_id: The session ID of the ongoing UI Auth (or
                 None if this is a login).
 
         Returns:
-            bytes: URL to redirect to
+            URL to redirect to
         """
         reqid, info = self._saml_client.prepare_for_authenticate(
             relay_state=client_redirect_url
@@ -109,15 +112,15 @@ def handle_redirect_request(self, client_redirect_url, ui_auth_session_id=None):
         # this shouldn't happen!
         raise Exception("prepare_for_authenticate didn't return a Location header")
 
-    async def handle_saml_response(self, request):
+    async def handle_saml_response(self, request: SynapseRequest) -> None:
         """Handle an incoming request to /_matrix/saml2/authn_response
 
         Args:
-            request (SynapseRequest): the incoming request from the browser. We'll
+            request: the incoming request from the browser. We'll
                 respond to it with a redirect.
 
         Returns:
-            Deferred[none]: Completes once we have handled the request.
+            Completes once we have handled the request.
         """
         resp_bytes = parse_string(request, "SAMLResponse", required=True)
         relay_state = parse_string(request, "RelayState", required=True)
@@ -310,6 +313,7 @@ def expire_sessions(self):
 
 
 def dot_replace_for_mxid(username: str) -> str:
+    """Replace any characters which are not allowed in Matrix IDs with a dot."""
     username = username.lower()
     username = DOT_REPLACE_PATTERN.sub(".", username)
 
@@ -321,7 +325,7 @@ def dot_replace_for_mxid(username: str) -> str:
 MXID_MAPPER_MAP = {
     "hexencode": map_username_to_mxid_localpart,
     "dotreplace": dot_replace_for_mxid,
-}
+}  # type: Dict[str, Callable[[str], str]]
 
 
 @attr.s
@@ -349,7 +353,7 @@ def __init__(self, parsed_config: SamlConfig, module_api: ModuleApi):
 
     def get_remote_user_id(
         self, saml_response: saml2.response.AuthnResponse, client_redirect_url: str
-    ):
+    ) -> str:
         """Extracts the remote user id from the SAML response"""
         try:
             return saml_response.ava["uid"][0]
@@ -428,14 +432,14 @@ def parse_config(config: dict) -> SamlConfig:
         return SamlConfig(mxid_source_attribute, mxid_mapper)
 
     @staticmethod
-    def get_saml_attributes(config: SamlConfig) -> Tuple[set, set]:
+    def get_saml_attributes(config: SamlConfig) -> Tuple[Set[str], Set[str]]:
         """Returns the required attributes of a SAML
 
         Args:
             config: A SamlConfig object containing configuration params for this provider
 
         Returns:
-            tuple[set,set]: The first set equates to the saml auth response
+            The first set equates to the saml auth response
                 attributes that are required for the module to function, whereas the
                 second set consists of those attributes which can be used if
                 available, but are not necessary
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index ec1542d416ae..4d40d3ac9cd0 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -18,8 +18,6 @@
 
 from unpaddedbase64 import decode_base64, encode_base64
 
-from twisted.internet import defer
-
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import NotFoundError, SynapseError
 from synapse.api.filtering import Filter
@@ -39,8 +37,7 @@ def __init__(self, hs):
         self.state_store = self.storage.state
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def get_old_rooms_from_upgraded_room(self, room_id):
+    async def get_old_rooms_from_upgraded_room(self, room_id):
         """Retrieves room IDs of old rooms in the history of an upgraded room.
 
         We do so by checking the m.room.create event of the room for a
@@ -60,7 +57,7 @@ def get_old_rooms_from_upgraded_room(self, room_id):
         historical_room_ids = []
 
         # The initial room must have been known for us to get this far
-        predecessor = yield self.store.get_room_predecessor(room_id)
+        predecessor = await self.store.get_room_predecessor(room_id)
 
         while True:
             if not predecessor:
@@ -75,7 +72,7 @@ def get_old_rooms_from_upgraded_room(self, room_id):
 
             # Don't add it to the list until we have checked that we are in the room
             try:
-                next_predecessor_room = yield self.store.get_room_predecessor(
+                next_predecessor_room = await self.store.get_room_predecessor(
                     predecessor_room_id
                 )
             except NotFoundError:
@@ -89,8 +86,7 @@ def get_old_rooms_from_upgraded_room(self, room_id):
 
         return historical_room_ids
 
-    @defer.inlineCallbacks
-    def search(self, user, content, batch=None):
+    async def search(self, user, content, batch=None):
         """Performs a full text search for a user.
 
         Args:
@@ -179,7 +175,7 @@ def search(self, user, content, batch=None):
         search_filter = Filter(filter_dict)
 
         # TODO: Search through left rooms too
-        rooms = yield self.store.get_rooms_for_local_user_where_membership_is(
+        rooms = await self.store.get_rooms_for_local_user_where_membership_is(
             user.to_string(),
             membership_list=[Membership.JOIN],
             # membership_list=[Membership.JOIN, Membership.LEAVE, Membership.Ban],
@@ -192,7 +188,7 @@ def search(self, user, content, batch=None):
             historical_room_ids = []
             for room_id in search_filter.rooms:
                 # Add any previous rooms to the search if they exist
-                ids = yield self.get_old_rooms_from_upgraded_room(room_id)
+                ids = await self.get_old_rooms_from_upgraded_room(room_id)
                 historical_room_ids += ids
 
             # Prevent any historical events from being filtered
@@ -223,7 +219,7 @@ def search(self, user, content, batch=None):
         count = None
 
         if order_by == "rank":
-            search_result = yield self.store.search_msgs(room_ids, search_term, keys)
+            search_result = await self.store.search_msgs(room_ids, search_term, keys)
 
             count = search_result["count"]
 
@@ -238,7 +234,7 @@ def search(self, user, content, batch=None):
 
             filtered_events = search_filter.filter([r["event"] for r in results])
 
-            events = yield filter_events_for_client(
+            events = await filter_events_for_client(
                 self.storage, user.to_string(), filtered_events
             )
 
@@ -267,7 +263,7 @@ def search(self, user, content, batch=None):
             # But only go around 5 times since otherwise synapse will be sad.
             while len(room_events) < search_filter.limit() and i < 5:
                 i += 1
-                search_result = yield self.store.search_rooms(
+                search_result = await self.store.search_rooms(
                     room_ids,
                     search_term,
                     keys,
@@ -288,7 +284,7 @@ def search(self, user, content, batch=None):
 
                 filtered_events = search_filter.filter([r["event"] for r in results])
 
-                events = yield filter_events_for_client(
+                events = await filter_events_for_client(
                     self.storage, user.to_string(), filtered_events
                 )
 
@@ -343,11 +339,11 @@ def search(self, user, content, batch=None):
         # If client has asked for "context" for each event (i.e. some surrounding
         # events and state), fetch that
         if event_context is not None:
-            now_token = yield self.hs.get_event_sources().get_current_token()
+            now_token = await self.hs.get_event_sources().get_current_token()
 
             contexts = {}
             for event in allowed_events:
-                res = yield self.store.get_events_around(
+                res = await self.store.get_events_around(
                     event.room_id, event.event_id, before_limit, after_limit
                 )
 
@@ -357,11 +353,11 @@ def search(self, user, content, batch=None):
                     len(res["events_after"]),
                 )
 
-                res["events_before"] = yield filter_events_for_client(
+                res["events_before"] = await filter_events_for_client(
                     self.storage, user.to_string(), res["events_before"]
                 )
 
-                res["events_after"] = yield filter_events_for_client(
+                res["events_after"] = await filter_events_for_client(
                     self.storage, user.to_string(), res["events_after"]
                 )
 
@@ -390,7 +386,7 @@ def search(self, user, content, batch=None):
                         [(EventTypes.Member, sender) for sender in senders]
                     )
 
-                    state = yield self.state_store.get_state_for_event(
+                    state = await self.state_store.get_state_for_event(
                         last_event_id, state_filter
                     )
 
@@ -412,10 +408,10 @@ def search(self, user, content, batch=None):
         time_now = self.clock.time_msec()
 
         for context in contexts.values():
-            context["events_before"] = yield self._event_serializer.serialize_events(
+            context["events_before"] = await self._event_serializer.serialize_events(
                 context["events_before"], time_now
             )
-            context["events_after"] = yield self._event_serializer.serialize_events(
+            context["events_after"] = await self._event_serializer.serialize_events(
                 context["events_after"], time_now
             )
 
@@ -423,7 +419,7 @@ def search(self, user, content, batch=None):
         if include_state:
             rooms = {e.room_id for e in allowed_events}
             for room_id in rooms:
-                state = yield self.state_handler.get_current_state(room_id)
+                state = await self.state_handler.get_current_state(room_id)
                 state_results[room_id] = list(state.values())
 
             state_results.values()
@@ -437,7 +433,7 @@ def search(self, user, content, batch=None):
                 {
                     "rank": rank_map[e.event_id],
                     "result": (
-                        yield self._event_serializer.serialize_event(e, time_now)
+                        await self._event_serializer.serialize_event(e, time_now)
                     ),
                     "context": contexts.get(e.event_id, {}),
                 }
@@ -452,7 +448,7 @@ def search(self, user, content, batch=None):
         if state_results:
             s = {}
             for room_id, state in state_results.items():
-                s[room_id] = yield self._event_serializer.serialize_events(
+                s[room_id] = await self._event_serializer.serialize_events(
                     state, time_now
                 )
 
diff --git a/synapse/handlers/set_password.py b/synapse/handlers/set_password.py
index 63d8f9aa0d54..4d245b618b17 100644
--- a/synapse/handlers/set_password.py
+++ b/synapse/handlers/set_password.py
@@ -35,16 +35,13 @@ def __init__(self, hs):
     async def set_password(
         self,
         user_id: str,
-        new_password: str,
+        password_hash: str,
         logout_devices: bool,
         requester: Optional[Requester] = None,
     ):
         if not self.hs.config.password_localdb_enabled:
             raise SynapseError(403, "Password change disabled", errcode=Codes.FORBIDDEN)
 
-        self._password_policy_handler.validate_password(new_password)
-        password_hash = await self._auth_handler.hash(new_password)
-
         try:
             await self.store.user_set_password_hash(user_id, password_hash)
         except StoreError as e:
diff --git a/synapse/http/client.py b/synapse/http/client.py
index 37975458246a..3cef747a4dca 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -49,7 +49,6 @@
 from synapse.logging.context import make_deferred_yieldable
 from synapse.logging.opentracing import set_tag, start_active_span, tags
 from synapse.util.async_helpers import timeout_deferred
-from synapse.util.caches import CACHE_SIZE_FACTOR
 
 logger = logging.getLogger(__name__)
 
@@ -241,7 +240,10 @@ def __getattr__(_self, attr):
         # tends to do so in batches, so we need to allow the pool to keep
         # lots of idle connections around.
         pool = HTTPConnectionPool(self.reactor)
-        pool.maxPersistentPerHost = max((100 * CACHE_SIZE_FACTOR, 5))
+        # XXX: The justification for using the cache factor here is that larger instances
+        # will need both more cache and more connections.
+        # Still, this should probably be a separate dial
+        pool.maxPersistentPerHost = max((100 * hs.config.caches.global_factor, 5))
         pool.cachedConnectionTimeout = 2 * 60
 
         self.agent = ProxyAgent(
@@ -359,6 +361,7 @@ def post_urlencoded_get_json(self, uri, args={}, headers=None):
         actual_headers = {
             b"Content-Type": [b"application/x-www-form-urlencoded"],
             b"User-Agent": [self.user_agent],
+            b"Accept": [b"application/json"],
         }
         if headers:
             actual_headers.update(headers)
@@ -399,6 +402,7 @@ def post_json_get_json(self, uri, post_json, headers=None):
         actual_headers = {
             b"Content-Type": [b"application/json"],
             b"User-Agent": [self.user_agent],
+            b"Accept": [b"application/json"],
         }
         if headers:
             actual_headers.update(headers)
@@ -434,6 +438,10 @@ def get_json(self, uri, args={}, headers=None):
 
             ValueError: if the response was not JSON
         """
+        actual_headers = {b"Accept": [b"application/json"]}
+        if headers:
+            actual_headers.update(headers)
+
         body = yield self.get_raw(uri, args, headers=headers)
         return json.loads(body)
 
@@ -467,6 +475,7 @@ def put_json(self, uri, json_body, args={}, headers=None):
         actual_headers = {
             b"Content-Type": [b"application/json"],
             b"User-Agent": [self.user_agent],
+            b"Accept": [b"application/json"],
         }
         if headers:
             actual_headers.update(headers)
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 6b0a532c05bd..44077f534912 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -19,7 +19,7 @@
 import sys
 from io import BytesIO
 
-from six import PY3, raise_from, string_types
+from six import raise_from, string_types
 from six.moves import urllib
 
 import attr
@@ -70,11 +70,7 @@
 
 MAX_LONG_RETRIES = 10
 MAX_SHORT_RETRIES = 3
-
-if PY3:
-    MAXINT = sys.maxsize
-else:
-    MAXINT = sys.maxint
+MAXINT = sys.maxsize
 
 
 _next_id = 1
@@ -408,7 +404,7 @@ def _send_request(
                         _sec_timeout,
                     )
 
-                    outgoing_requests_counter.labels(method_bytes).inc()
+                    outgoing_requests_counter.labels(request.method).inc()
 
                     try:
                         with Measure(self.clock, "outbound_request"):
@@ -434,7 +430,9 @@ def _send_request(
                         logger.info("Failed to send request: %s", e)
                         raise_from(RequestSendFailed(e, can_retry=True), e)
 
-                    incoming_responses_counter.labels(method_bytes, response.code).inc()
+                    incoming_responses_counter.labels(
+                        request.method, response.code
+                    ).inc()
 
                     set_tag(tags.HTTP_STATUS_CODE, response.code)
 
diff --git a/synapse/http/site.py b/synapse/http/site.py
index 32feb0d968db..514f2f14029b 100644
--- a/synapse/http/site.py
+++ b/synapse/http/site.py
@@ -15,6 +15,7 @@
 import logging
 import time
 
+from twisted.python.failure import Failure
 from twisted.web.server import Request, Site
 
 from synapse.http import redact_uri
@@ -190,6 +191,12 @@ def connectionLost(self, reason):
         Overrides twisted.web.server.Request.connectionLost to record the finish time and
         do logging.
         """
+        # There is a bug in Twisted where reason is not wrapped in a Failure object
+        # Detect this and wrap it manually as a workaround
+        # More information: https://github.com/matrix-org/synapse/issues/7441
+        if not isinstance(reason, Failure):
+            reason = Failure(reason)
+
         self.finish_time = time.time()
         Request.connectionLost(self, reason)
 
diff --git a/synapse/logging/utils.py b/synapse/logging/utils.py
index 0c2527bd8686..99049bb5d8f3 100644
--- a/synapse/logging/utils.py
+++ b/synapse/logging/utils.py
@@ -20,8 +20,6 @@
 from functools import wraps
 from inspect import getcallargs
 
-from six import PY3
-
 _TIME_FUNC_ID = 0
 
 
@@ -30,12 +28,8 @@ def _log_debug_as_f(f, msg, msg_args):
     logger = logging.getLogger(name)
 
     if logger.isEnabledFor(logging.DEBUG):
-        if PY3:
-            lineno = f.__code__.co_firstlineno
-            pathname = f.__code__.co_filename
-        else:
-            lineno = f.func_code.co_firstlineno
-            pathname = f.func_code.co_filename
+        lineno = f.__code__.co_firstlineno
+        pathname = f.__code__.co_filename
 
         record = logging.LogRecord(
             name=name,
diff --git a/synapse/metrics/_exposition.py b/synapse/metrics/_exposition.py
index a248103191ad..ab7f948ed453 100644
--- a/synapse/metrics/_exposition.py
+++ b/synapse/metrics/_exposition.py
@@ -33,6 +33,8 @@
 
 from twisted.web.resource import Resource
 
+from synapse.util import caches
+
 try:
     from prometheus_client.samples import Sample
 except ImportError:
@@ -103,13 +105,15 @@ def nameify_sample(sample):
 
 
 def generate_latest(registry, emit_help=False):
-    output = []
 
-    for metric in registry.collect():
+    # Trigger the cache metrics to be rescraped, which updates the common
+    # metrics but do not produce metrics themselves
+    for collector in caches.collectors_by_name.values():
+        collector.collect()
 
-        if metric.name.startswith("__unused"):
-            continue
+    output = []
 
+    for metric in registry.collect():
         if not metric.samples:
             # No samples, don't bother.
             continue
diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index 433ca2f416fa..e75d964ac849 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -51,6 +51,7 @@
     "cache",
     "push_rules_delta_state_cache_metric",
     cache=[],  # Meaningless size, as this isn't a cache that stores values
+    resizable=False,
 )
 
 
@@ -67,7 +68,8 @@ def __init__(self, hs):
         self.room_push_rule_cache_metrics = register_cache(
             "cache",
             "room_push_rule_cache",
-            cache=[],  # Meaningless size, as this isn't a cache that stores values
+            cache=[],  # Meaningless size, as this isn't a cache that stores values,
+            resizable=False,
         )
 
     @defer.inlineCallbacks
diff --git a/synapse/push/httppusher.py b/synapse/push/httppusher.py
index 73a63ec78af8..3efc825d1592 100644
--- a/synapse/push/httppusher.py
+++ b/synapse/push/httppusher.py
@@ -15,8 +15,6 @@
 # limitations under the License.
 import logging
 
-import six
-
 from prometheus_client import Counter
 
 from twisted.internet import defer
@@ -28,9 +26,6 @@
 
 from . import push_rule_evaluator, push_tools
 
-if six.PY3:
-    long = int
-
 logger = logging.getLogger(__name__)
 
 http_push_processed_counter = Counter(
@@ -322,7 +317,7 @@ def _build_notification_dict(self, event, tweaks, badge):
                         {
                             "app_id": self.app_id,
                             "pushkey": self.pushkey,
-                            "pushkey_ts": long(self.pushkey_ts / 1000),
+                            "pushkey_ts": int(self.pushkey_ts / 1000),
                             "data": self.data_minus_url,
                         }
                     ],
@@ -351,7 +346,7 @@ def _build_notification_dict(self, event, tweaks, badge):
                     {
                         "app_id": self.app_id,
                         "pushkey": self.pushkey,
-                        "pushkey_ts": long(self.pushkey_ts / 1000),
+                        "pushkey_ts": int(self.pushkey_ts / 1000),
                         "data": self.data_minus_url,
                         "tweaks": tweaks,
                     }
@@ -413,7 +408,7 @@ def _send_badge(self, badge):
                     {
                         "app_id": self.app_id,
                         "pushkey": self.pushkey,
-                        "pushkey_ts": long(self.pushkey_ts / 1000),
+                        "pushkey_ts": int(self.pushkey_ts / 1000),
                         "data": self.data_minus_url,
                     }
                 ],
diff --git a/synapse/push/push_rule_evaluator.py b/synapse/push/push_rule_evaluator.py
index 4cd702b5facb..11032491afad 100644
--- a/synapse/push/push_rule_evaluator.py
+++ b/synapse/push/push_rule_evaluator.py
@@ -22,7 +22,7 @@
 
 from synapse.events import EventBase
 from synapse.types import UserID
-from synapse.util.caches import CACHE_SIZE_FACTOR, register_cache
+from synapse.util.caches import register_cache
 from synapse.util.caches.lrucache import LruCache
 
 logger = logging.getLogger(__name__)
@@ -165,7 +165,7 @@ def _get_value(self, dotted_key: str) -> str:
 
 
 # Caches (string, is_glob, word_boundary) -> regex for push. See _glob_matches
-regex_cache = LruCache(50000 * CACHE_SIZE_FACTOR)
+regex_cache = LruCache(50000)
 register_cache("cache", "regex_push_cache", regex_cache)
 
 
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 39c99a280230..8b4312e5a3e5 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -92,6 +92,7 @@
         'eliot<1.8.0;python_version<"3.5.3"',
     ],
     "saml2": ["pysaml2>=4.5.0"],
+    "oidc": ["authlib>=0.14.0"],
     "systemd": ["systemd-python>=231"],
     "url_preview": ["lxml>=3.5.0"],
     "test": ["mock>=2.0", "parameterized"],
diff --git a/synapse/replication/http/__init__.py b/synapse/replication/http/__init__.py
index 4613b2538ce8..a909744e9345 100644
--- a/synapse/replication/http/__init__.py
+++ b/synapse/replication/http/__init__.py
@@ -34,9 +34,12 @@ def __init__(self, hs):
 
     def register_servlets(self, hs):
         send_event.register_servlets(hs, self)
-        membership.register_servlets(hs, self)
         federation.register_servlets(hs, self)
-        login.register_servlets(hs, self)
-        register.register_servlets(hs, self)
-        devices.register_servlets(hs, self)
-        streams.register_servlets(hs, self)
+
+        # The following can't currently be instantiated on workers.
+        if hs.config.worker.worker_app is None:
+            membership.register_servlets(hs, self)
+            login.register_servlets(hs, self)
+            register.register_servlets(hs, self)
+            devices.register_servlets(hs, self)
+            streams.register_servlets(hs, self)
diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
index f88c80ae84b3..c3136a4eb93f 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -141,17 +141,26 @@ def make_client(cls, hs):
         Returns a callable that accepts the same parameters as `_serialize_payload`.
         """
         clock = hs.get_clock()
-        host = hs.config.worker_replication_host
-        port = hs.config.worker_replication_http_port
-
         client = hs.get_simple_http_client()
 
+        master_host = hs.config.worker_replication_host
+        master_port = hs.config.worker_replication_http_port
+
+        instance_map = hs.config.worker.instance_map
+
         @trace(opname="outgoing_replication_request")
         @defer.inlineCallbacks
         def send_request(instance_name="master", **kwargs):
-            # Currently we only support sending requests to master process.
-            if instance_name != "master":
-                raise Exception("Unknown instance")
+            if instance_name == "master":
+                host = master_host
+                port = master_port
+            elif instance_name in instance_map:
+                host = instance_map[instance_name].host
+                port = instance_map[instance_name].port
+            else:
+                raise Exception(
+                    "Instance %r not in 'instance_map' config" % (instance_name,)
+                )
 
             data = yield cls._serialize_payload(**kwargs)
 
diff --git a/synapse/replication/http/streams.py b/synapse/replication/http/streams.py
index 0459f582bfc7..b705a8e16c59 100644
--- a/synapse/replication/http/streams.py
+++ b/synapse/replication/http/streams.py
@@ -52,9 +52,9 @@ def __init__(self, hs):
 
         self._instance_name = hs.get_instance_name()
 
-        # We pull the streams from the replication steamer (if we try and make
+        # We pull the streams from the replication handler (if we try and make
         # them ourselves we end up in an import loop).
-        self.streams = hs.get_replication_streamer().get_streams()
+        self.streams = hs.get_tcp_replication().get_streams()
 
     @staticmethod
     def _serialize_payload(stream_name, from_token, upto_token):
diff --git a/synapse/replication/slave/storage/_base.py b/synapse/replication/slave/storage/_base.py
index 5d7c8871a4e6..f9e2533e9639 100644
--- a/synapse/replication/slave/storage/_base.py
+++ b/synapse/replication/slave/storage/_base.py
@@ -16,65 +16,28 @@
 import logging
 from typing import Optional
 
-import six
-
-from synapse.storage.data_stores.main.cache import (
-    CURRENT_STATE_CACHE_NAME,
-    CacheInvalidationWorkerStore,
-)
+from synapse.storage.data_stores.main.cache import CacheInvalidationWorkerStore
 from synapse.storage.database import Database
 from synapse.storage.engines import PostgresEngine
-
-from ._slaved_id_tracker import SlavedIdTracker
+from synapse.storage.util.id_generators import MultiWriterIdGenerator
 
 logger = logging.getLogger(__name__)
 
 
-def __func__(inp):
-    if six.PY3:
-        return inp
-    else:
-        return inp.__func__
-
-
 class BaseSlavedStore(CacheInvalidationWorkerStore):
     def __init__(self, database: Database, db_conn, hs):
         super(BaseSlavedStore, self).__init__(database, db_conn, hs)
         if isinstance(self.database_engine, PostgresEngine):
-            self._cache_id_gen = SlavedIdTracker(
-                db_conn, "cache_invalidation_stream", "stream_id"
-            )  # type: Optional[SlavedIdTracker]
+            self._cache_id_gen = MultiWriterIdGenerator(
+                db_conn,
+                database,
+                instance_name=hs.get_instance_name(),
+                table="cache_invalidation_stream_by_instance",
+                instance_column="instance_name",
+                id_column="stream_id",
+                sequence_name="cache_invalidation_stream_seq",
+            )  # type: Optional[MultiWriterIdGenerator]
         else:
             self._cache_id_gen = None
 
         self.hs = hs
-
-    def get_cache_stream_token(self):
-        if self._cache_id_gen:
-            return self._cache_id_gen.get_current_token()
-        else:
-            return 0
-
-    def process_replication_rows(self, stream_name, token, rows):
-        if stream_name == "caches":
-            if self._cache_id_gen:
-                self._cache_id_gen.advance(token)
-            for row in rows:
-                if row.cache_func == CURRENT_STATE_CACHE_NAME:
-                    if row.keys is None:
-                        raise Exception(
-                            "Can't send an 'invalidate all' for current state cache"
-                        )
-
-                    room_id = row.keys[0]
-                    members_changed = set(row.keys[1:])
-                    self._invalidate_state_caches(room_id, members_changed)
-                else:
-                    self._attempt_to_invalidate_cache(row.cache_func, row.keys)
-
-    def _invalidate_cache_and_stream(self, txn, cache_func, keys):
-        txn.call_after(cache_func.invalidate, keys)
-        txn.call_after(self._send_invalidation_poke, cache_func, keys)
-
-    def _send_invalidation_poke(self, cache_func, keys):
-        self.hs.get_tcp_replication().send_invalidate_cache(cache_func, keys)
diff --git a/synapse/replication/slave/storage/account_data.py b/synapse/replication/slave/storage/account_data.py
index 65e54b1c71b5..2a4f5c7cfd65 100644
--- a/synapse/replication/slave/storage/account_data.py
+++ b/synapse/replication/slave/storage/account_data.py
@@ -32,7 +32,7 @@ def __init__(self, database: Database, db_conn, hs):
     def get_max_account_data_stream_id(self):
         return self._account_data_id_gen.get_current_token()
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "tag_account_data":
             self._account_data_id_gen.advance(token)
             for row in rows:
@@ -51,6 +51,4 @@ def process_replication_rows(self, stream_name, token, rows):
                     (row.user_id, row.room_id, row.data_type)
                 )
                 self._account_data_stream_cache.entity_has_changed(row.user_id, token)
-        return super(SlavedAccountDataStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/client_ips.py b/synapse/replication/slave/storage/client_ips.py
index fbf996e33a10..1a38f53dfb8b 100644
--- a/synapse/replication/slave/storage/client_ips.py
+++ b/synapse/replication/slave/storage/client_ips.py
@@ -15,7 +15,6 @@
 
 from synapse.storage.data_stores.main.client_ips import LAST_SEEN_GRANULARITY
 from synapse.storage.database import Database
-from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.caches.descriptors import Cache
 
 from ._base import BaseSlavedStore
@@ -26,7 +25,7 @@ def __init__(self, database: Database, db_conn, hs):
         super(SlavedClientIpStore, self).__init__(database, db_conn, hs)
 
         self.client_ip_last_seen = Cache(
-            name="client_ip_last_seen", keylen=4, max_entries=50000 * CACHE_SIZE_FACTOR
+            name="client_ip_last_seen", keylen=4, max_entries=50000
         )
 
     def insert_client_ip(self, user_id, access_token, ip, user_agent, device_id):
diff --git a/synapse/replication/slave/storage/deviceinbox.py b/synapse/replication/slave/storage/deviceinbox.py
index c923751e50d6..6e7fd259d46f 100644
--- a/synapse/replication/slave/storage/deviceinbox.py
+++ b/synapse/replication/slave/storage/deviceinbox.py
@@ -43,7 +43,7 @@ def __init__(self, database: Database, db_conn, hs):
             expiry_ms=30 * 60 * 1000,
         )
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "to_device":
             self._device_inbox_id_gen.advance(token)
             for row in rows:
@@ -55,6 +55,4 @@ def process_replication_rows(self, stream_name, token, rows):
                     self._device_federation_outbox_stream_cache.entity_has_changed(
                         row.entity, token
                     )
-        return super(SlavedDeviceInboxStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/devices.py b/synapse/replication/slave/storage/devices.py
index 58fb0eaae3ca..9d8067342fd2 100644
--- a/synapse/replication/slave/storage/devices.py
+++ b/synapse/replication/slave/storage/devices.py
@@ -48,7 +48,7 @@ def __init__(self, database: Database, db_conn, hs):
             "DeviceListFederationStreamChangeCache", device_list_max
         )
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == DeviceListsStream.NAME:
             self._device_list_id_gen.advance(token)
             self._invalidate_caches_for_devices(token, rows)
@@ -56,9 +56,7 @@ def process_replication_rows(self, stream_name, token, rows):
             self._device_list_id_gen.advance(token)
             for row in rows:
                 self._user_signature_stream_cache.entity_has_changed(row.user_id, token)
-        return super(SlavedDeviceStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
 
     def _invalidate_caches_for_devices(self, token, rows):
         for row in rows:
diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py
index 15011259dfc3..1a1a50a24f07 100644
--- a/synapse/replication/slave/storage/events.py
+++ b/synapse/replication/slave/storage/events.py
@@ -15,11 +15,6 @@
 # limitations under the License.
 import logging
 
-from synapse.api.constants import EventTypes
-from synapse.replication.tcp.streams.events import (
-    EventsStreamCurrentStateRow,
-    EventsStreamEventRow,
-)
 from synapse.storage.data_stores.main.event_federation import EventFederationWorkerStore
 from synapse.storage.data_stores.main.event_push_actions import (
     EventPushActionsWorkerStore,
@@ -35,7 +30,6 @@
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 from ._base import BaseSlavedStore
-from ._slaved_id_tracker import SlavedIdTracker
 
 logger = logging.getLogger(__name__)
 
@@ -62,11 +56,6 @@ class SlavedEventStore(
     BaseSlavedStore,
 ):
     def __init__(self, database: Database, db_conn, hs):
-        self._stream_id_gen = SlavedIdTracker(db_conn, "events", "stream_ordering")
-        self._backfill_id_gen = SlavedIdTracker(
-            db_conn, "events", "stream_ordering", step=-1
-        )
-
         super(SlavedEventStore, self).__init__(database, db_conn, hs)
 
         events_max = self._stream_id_gen.get_current_token()
@@ -92,83 +81,3 @@ def get_room_max_stream_ordering(self):
 
     def get_room_min_stream_ordering(self):
         return self._backfill_id_gen.get_current_token()
-
-    def process_replication_rows(self, stream_name, token, rows):
-        if stream_name == "events":
-            self._stream_id_gen.advance(token)
-            for row in rows:
-                self._process_event_stream_row(token, row)
-        elif stream_name == "backfill":
-            self._backfill_id_gen.advance(-token)
-            for row in rows:
-                self.invalidate_caches_for_event(
-                    -token,
-                    row.event_id,
-                    row.room_id,
-                    row.type,
-                    row.state_key,
-                    row.redacts,
-                    row.relates_to,
-                    backfilled=True,
-                )
-        return super(SlavedEventStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
-
-    def _process_event_stream_row(self, token, row):
-        data = row.data
-
-        if row.type == EventsStreamEventRow.TypeId:
-            self.invalidate_caches_for_event(
-                token,
-                data.event_id,
-                data.room_id,
-                data.type,
-                data.state_key,
-                data.redacts,
-                data.relates_to,
-                backfilled=False,
-            )
-        elif row.type == EventsStreamCurrentStateRow.TypeId:
-            self._curr_state_delta_stream_cache.entity_has_changed(
-                row.data.room_id, token
-            )
-
-            if data.type == EventTypes.Member:
-                self.get_rooms_for_user_with_stream_ordering.invalidate(
-                    (data.state_key,)
-                )
-        else:
-            raise Exception("Unknown events stream row type %s" % (row.type,))
-
-    def invalidate_caches_for_event(
-        self,
-        stream_ordering,
-        event_id,
-        room_id,
-        etype,
-        state_key,
-        redacts,
-        relates_to,
-        backfilled,
-    ):
-        self._invalidate_get_event_cache(event_id)
-
-        self.get_latest_event_ids_in_room.invalidate((room_id,))
-
-        self.get_unread_event_push_actions_by_room_for_user.invalidate_many((room_id,))
-
-        if not backfilled:
-            self._events_stream_cache.entity_has_changed(room_id, stream_ordering)
-
-        if redacts:
-            self._invalidate_get_event_cache(redacts)
-
-        if etype == EventTypes.Member:
-            self._membership_stream_cache.entity_has_changed(state_key, stream_ordering)
-            self.get_invited_rooms_for_local_user.invalidate((state_key,))
-
-        if relates_to:
-            self.get_relations_for_event.invalidate_many((relates_to,))
-            self.get_aggregation_groups_for_event.invalidate_many((relates_to,))
-            self.get_applicable_edit.invalidate((relates_to,))
diff --git a/synapse/replication/slave/storage/groups.py b/synapse/replication/slave/storage/groups.py
index 01bcf0e88275..1851e7d5252e 100644
--- a/synapse/replication/slave/storage/groups.py
+++ b/synapse/replication/slave/storage/groups.py
@@ -37,12 +37,10 @@ def __init__(self, database: Database, db_conn, hs):
     def get_group_stream_token(self):
         return self._group_updates_id_gen.get_current_token()
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "groups":
             self._group_updates_id_gen.advance(token)
             for row in rows:
                 self._group_updates_stream_cache.entity_has_changed(row.user_id, token)
 
-        return super(SlavedGroupServerStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/presence.py b/synapse/replication/slave/storage/presence.py
index fae312507244..4e0124842dbe 100644
--- a/synapse/replication/slave/storage/presence.py
+++ b/synapse/replication/slave/storage/presence.py
@@ -18,7 +18,7 @@
 from synapse.storage.database import Database
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
-from ._base import BaseSlavedStore, __func__
+from ._base import BaseSlavedStore
 from ._slaved_id_tracker import SlavedIdTracker
 
 
@@ -27,26 +27,24 @@ def __init__(self, database: Database, db_conn, hs):
         super(SlavedPresenceStore, self).__init__(database, db_conn, hs)
         self._presence_id_gen = SlavedIdTracker(db_conn, "presence_stream", "stream_id")
 
-        self._presence_on_startup = self._get_active_presence(db_conn)
+        self._presence_on_startup = self._get_active_presence(db_conn)  # type: ignore
 
         self.presence_stream_cache = StreamChangeCache(
             "PresenceStreamChangeCache", self._presence_id_gen.get_current_token()
         )
 
-    _get_active_presence = __func__(DataStore._get_active_presence)
-    take_presence_startup_info = __func__(DataStore.take_presence_startup_info)
+    _get_active_presence = DataStore._get_active_presence
+    take_presence_startup_info = DataStore.take_presence_startup_info
     _get_presence_for_user = PresenceStore.__dict__["_get_presence_for_user"]
     get_presence_for_users = PresenceStore.__dict__["get_presence_for_users"]
 
     def get_current_presence_token(self):
         return self._presence_id_gen.get_current_token()
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "presence":
             self._presence_id_gen.advance(token)
             for row in rows:
                 self.presence_stream_cache.entity_has_changed(row.user_id, token)
                 self._get_presence_for_user.invalidate((row.user_id,))
-        return super(SlavedPresenceStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/push_rule.py b/synapse/replication/slave/storage/push_rule.py
index 6138796da4e8..6adb19463afa 100644
--- a/synapse/replication/slave/storage/push_rule.py
+++ b/synapse/replication/slave/storage/push_rule.py
@@ -15,19 +15,11 @@
 # limitations under the License.
 
 from synapse.storage.data_stores.main.push_rule import PushRulesWorkerStore
-from synapse.storage.database import Database
 
-from ._slaved_id_tracker import SlavedIdTracker
 from .events import SlavedEventStore
 
 
 class SlavedPushRuleStore(SlavedEventStore, PushRulesWorkerStore):
-    def __init__(self, database: Database, db_conn, hs):
-        self._push_rules_stream_id_gen = SlavedIdTracker(
-            db_conn, "push_rules_stream", "stream_id"
-        )
-        super(SlavedPushRuleStore, self).__init__(database, db_conn, hs)
-
     def get_push_rules_stream_token(self):
         return (
             self._push_rules_stream_id_gen.get_current_token(),
@@ -37,13 +29,11 @@ def get_push_rules_stream_token(self):
     def get_max_push_rules_stream_id(self):
         return self._push_rules_stream_id_gen.get_current_token()
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "push_rules":
             self._push_rules_stream_id_gen.advance(token)
             for row in rows:
                 self.get_push_rules_for_user.invalidate((row.user_id,))
                 self.get_push_rules_enabled_for_user.invalidate((row.user_id,))
                 self.push_rules_stream_cache.entity_has_changed(row.user_id, token)
-        return super(SlavedPushRuleStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/pushers.py b/synapse/replication/slave/storage/pushers.py
index 67be3379457b..cb78b49acbb0 100644
--- a/synapse/replication/slave/storage/pushers.py
+++ b/synapse/replication/slave/storage/pushers.py
@@ -31,9 +31,7 @@ def __init__(self, database: Database, db_conn, hs):
     def get_pushers_stream_token(self):
         return self._pushers_id_gen.get_current_token()
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "pushers":
             self._pushers_id_gen.advance(token)
-        return super(SlavedPusherStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/receipts.py b/synapse/replication/slave/storage/receipts.py
index 993432edcb49..be716cc558b0 100644
--- a/synapse/replication/slave/storage/receipts.py
+++ b/synapse/replication/slave/storage/receipts.py
@@ -51,7 +51,7 @@ def invalidate_caches_for_receipt(self, room_id, receipt_type, user_id):
         self._invalidate_get_users_with_receipts_in_room(room_id, receipt_type, user_id)
         self.get_receipts_for_room.invalidate((room_id, receipt_type))
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "receipts":
             self._receipts_id_gen.advance(token)
             for row in rows:
@@ -60,6 +60,4 @@ def process_replication_rows(self, stream_name, token, rows):
                 )
                 self._receipts_stream_cache.entity_has_changed(row.room_id, token)
 
-        return super(SlavedReceiptsStore, self).process_replication_rows(
-            stream_name, token, rows
-        )
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/room.py b/synapse/replication/slave/storage/room.py
index 10dda8708f85..8873bf37e598 100644
--- a/synapse/replication/slave/storage/room.py
+++ b/synapse/replication/slave/storage/room.py
@@ -30,8 +30,8 @@ def __init__(self, database: Database, db_conn, hs):
     def get_current_public_room_stream_id(self):
         return self._public_room_id_gen.get_current_token()
 
-    def process_replication_rows(self, stream_name, token, rows):
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
         if stream_name == "public_rooms":
             self._public_room_id_gen.advance(token)
 
-        return super(RoomStore, self).process_replication_rows(stream_name, token, rows)
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py
index 3bbf3c356929..28826302f5a9 100644
--- a/synapse/replication/tcp/client.py
+++ b/synapse/replication/tcp/client.py
@@ -16,12 +16,17 @@
 """
 
 import logging
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Tuple
 
 from twisted.internet.protocol import ReconnectingClientFactory
 
-from synapse.replication.slave.storage._base import BaseSlavedStore
+from synapse.api.constants import EventTypes
 from synapse.replication.tcp.protocol import ClientReplicationStreamProtocol
+from synapse.replication.tcp.streams.events import (
+    EventsStream,
+    EventsStreamEventRow,
+    EventsStreamRow,
+)
 
 if TYPE_CHECKING:
     from synapse.server import HomeServer
@@ -83,8 +88,10 @@ class ReplicationDataHandler:
     to handle updates in additional ways.
     """
 
-    def __init__(self, store: BaseSlavedStore):
-        self.store = store
+    def __init__(self, hs: "HomeServer"):
+        self.store = hs.get_datastore()
+        self.pusher_pool = hs.get_pusherpool()
+        self.notifier = hs.get_notifier()
 
     async def on_rdata(
         self, stream_name: str, instance_name: str, token: int, rows: list
@@ -100,10 +107,32 @@ async def on_rdata(
             token: stream token for this batch of rows
             rows: a list of Stream.ROW_TYPE objects as returned by Stream.parse_row.
         """
-        self.store.process_replication_rows(stream_name, token, rows)
-
-    async def on_position(self, stream_name: str, token: int):
-        self.store.process_replication_rows(stream_name, token, [])
+        self.store.process_replication_rows(stream_name, instance_name, token, rows)
+
+        if stream_name == EventsStream.NAME:
+            # We shouldn't get multiple rows per token for events stream, so
+            # we don't need to optimise this for multiple rows.
+            for row in rows:
+                if row.type != EventsStreamEventRow.TypeId:
+                    continue
+                assert isinstance(row, EventsStreamRow)
+
+                event = await self.store.get_event(
+                    row.data.event_id, allow_rejected=True
+                )
+                if event.rejected_reason:
+                    continue
+
+                extra_users = ()  # type: Tuple[str, ...]
+                if event.type == EventTypes.Member:
+                    extra_users = (event.state_key,)
+                max_token = self.store.get_room_max_stream_ordering()
+                self.notifier.on_new_room_event(event, token, max_token, extra_users)
+
+            await self.pusher_pool.on_new_notifications(token, token)
+
+    async def on_position(self, stream_name: str, instance_name: str, token: int):
+        self.store.process_replication_rows(stream_name, instance_name, token, [])
 
     def on_remote_server_up(self, server: str):
         """Called when get a new REMOTE_SERVER_UP command."""
diff --git a/synapse/replication/tcp/commands.py b/synapse/replication/tcp/commands.py
index f58e384d172e..c04f6228161a 100644
--- a/synapse/replication/tcp/commands.py
+++ b/synapse/replication/tcp/commands.py
@@ -341,37 +341,6 @@ def to_line(self):
         return " ".join((self.app_id, self.push_key, self.user_id))
 
 
-class InvalidateCacheCommand(Command):
-    """Sent by the client to invalidate an upstream cache.
-
-    THIS IS NOT RELIABLE, AND SHOULD *NOT* BE USED ACCEPT FOR THINGS THAT ARE
-    NOT DISASTROUS IF WE DROP ON THE FLOOR.
-
-    Mainly used to invalidate destination retry timing caches.
-
-    Format::
-
-        INVALIDATE_CACHE <cache_func> <keys_json>
-
-    Where <keys_json> is a json list.
-    """
-
-    NAME = "INVALIDATE_CACHE"
-
-    def __init__(self, cache_func, keys):
-        self.cache_func = cache_func
-        self.keys = keys
-
-    @classmethod
-    def from_line(cls, line):
-        cache_func, keys_json = line.split(" ", 1)
-
-        return cls(cache_func, json.loads(keys_json))
-
-    def to_line(self):
-        return " ".join((self.cache_func, _json_encoder.encode(self.keys)))
-
-
 class UserIpCommand(Command):
     """Sent periodically when a worker sees activity from a client.
 
@@ -439,7 +408,6 @@ class RemoteServerUpCommand(_SimpleCommand):
     UserSyncCommand,
     FederationAckCommand,
     RemovePusherCommand,
-    InvalidateCacheCommand,
     UserIpCommand,
     RemoteServerUpCommand,
     ClearUserSyncsCommand,
@@ -467,7 +435,6 @@ class RemoteServerUpCommand(_SimpleCommand):
     ClearUserSyncsCommand.NAME,
     FederationAckCommand.NAME,
     RemovePusherCommand.NAME,
-    InvalidateCacheCommand.NAME,
     UserIpCommand.NAME,
     ErrorCommand.NAME,
     RemoteServerUpCommand.NAME,
diff --git a/synapse/replication/tcp/handler.py b/synapse/replication/tcp/handler.py
index 4328b38e9dfe..acfa66a7a842 100644
--- a/synapse/replication/tcp/handler.py
+++ b/synapse/replication/tcp/handler.py
@@ -15,18 +15,7 @@
 # limitations under the License.
 
 import logging
-from typing import (
-    Any,
-    Callable,
-    Dict,
-    Iterable,
-    Iterator,
-    List,
-    Optional,
-    Set,
-    Tuple,
-    TypeVar,
-)
+from typing import Any, Dict, Iterable, Iterator, List, Optional, Set, Tuple, TypeVar
 
 from prometheus_client import Counter
 
@@ -38,7 +27,6 @@
     ClearUserSyncsCommand,
     Command,
     FederationAckCommand,
-    InvalidateCacheCommand,
     PositionCommand,
     RdataCommand,
     RemoteServerUpCommand,
@@ -48,7 +36,12 @@
     UserSyncCommand,
 )
 from synapse.replication.tcp.protocol import AbstractConnection
-from synapse.replication.tcp.streams import STREAMS_MAP, Stream
+from synapse.replication.tcp.streams import (
+    STREAMS_MAP,
+    CachesStream,
+    FederationStream,
+    Stream,
+)
 from synapse.util.async_helpers import Linearizer
 
 logger = logging.getLogger(__name__)
@@ -85,6 +78,26 @@ def __init__(self, hs):
             stream.NAME: stream(hs) for stream in STREAMS_MAP.values()
         }  # type: Dict[str, Stream]
 
+        # List of streams that this instance is the source of
+        self._streams_to_replicate = []  # type: List[Stream]
+
+        for stream in self._streams.values():
+            if stream.NAME == CachesStream.NAME:
+                # All workers can write to the cache invalidation stream.
+                self._streams_to_replicate.append(stream)
+                continue
+
+            # Only add any other streams if we're on master.
+            if hs.config.worker_app is not None:
+                continue
+
+            if stream.NAME == FederationStream.NAME and hs.config.send_federation:
+                # We only support federation stream if federation sending
+                # has been disabled on the master.
+                continue
+
+            self._streams_to_replicate.append(stream)
+
         self._position_linearizer = Linearizer(
             "replication_position", clock=self._clock
         )
@@ -162,16 +175,33 @@ def start_replication(self, hs):
             port = hs.config.worker_replication_port
             hs.get_reactor().connectTCP(host, port, self._factory)
 
+    def get_streams(self) -> Dict[str, Stream]:
+        """Get a map from stream name to all streams.
+        """
+        return self._streams
+
+    def get_streams_to_replicate(self) -> List[Stream]:
+        """Get a list of streams that this instances replicates.
+        """
+        return self._streams_to_replicate
+
     async def on_REPLICATE(self, conn: AbstractConnection, cmd: ReplicateCommand):
-        # We only want to announce positions by the writer of the streams.
-        # Currently this is just the master process.
-        if not self._is_master:
-            return
+        self.send_positions_to_connection(conn)
 
-        for stream_name, stream in self._streams.items():
-            current_token = stream.current_token()
+    def send_positions_to_connection(self, conn: AbstractConnection):
+        """Send current position of all streams this process is source of to
+        the connection.
+        """
+
+        # We respond with current position of all streams this instance
+        # replicates.
+        for stream in self.get_streams_to_replicate():
             self.send_command(
-                PositionCommand(stream_name, self._instance_name, current_token)
+                PositionCommand(
+                    stream.NAME,
+                    self._instance_name,
+                    stream.current_token(self._instance_name),
+                )
             )
 
     async def on_USER_SYNC(self, conn: AbstractConnection, cmd: UserSyncCommand):
@@ -208,18 +238,6 @@ async def on_REMOVE_PUSHER(
 
             self._notifier.on_new_replication_data()
 
-    async def on_INVALIDATE_CACHE(
-        self, conn: AbstractConnection, cmd: InvalidateCacheCommand
-    ):
-        invalidate_cache_counter.inc()
-
-        if self._is_master:
-            # We invalidate the cache locally, but then also stream that to other
-            # workers.
-            await self._store.invalidate_cache_and_stream(
-                cmd.cache_func, tuple(cmd.keys)
-            )
-
     async def on_USER_IP(self, conn: AbstractConnection, cmd: UserIpCommand):
         user_ip_cache_counter.inc()
 
@@ -293,7 +311,7 @@ async def on_rdata(
             rows: a list of Stream.ROW_TYPE objects as returned by
                 Stream.parse_row.
         """
-        logger.debug("Received rdata %s -> %s", stream_name, token)
+        logger.debug("Received rdata %s (%s) -> %s", stream_name, instance_name, token)
         await self._replication_data_handler.on_rdata(
             stream_name, instance_name, token, rows
         )
@@ -324,7 +342,7 @@ async def on_POSITION(self, conn: AbstractConnection, cmd: PositionCommand):
             self._pending_batches.pop(stream_name, [])
 
             # Find where we previously streamed up to.
-            current_token = stream.current_token()
+            current_token = stream.current_token(cmd.instance_name)
 
             # If the position token matches our current token then we're up to
             # date and there's nothing to do. Otherwise, fetch all updates
@@ -361,7 +379,9 @@ async def on_POSITION(self, conn: AbstractConnection, cmd: PositionCommand):
             logger.info("Caught up with stream '%s' to %i", stream_name, cmd.token)
 
             # We've now caught up to position sent to us, notify handler.
-            await self._replication_data_handler.on_position(stream_name, cmd.token)
+            await self._replication_data_handler.on_position(
+                cmd.stream_name, cmd.instance_name, cmd.token
+            )
 
             self._streams_by_connection.setdefault(conn, set()).add(stream_name)
 
@@ -489,12 +509,6 @@ def send_remove_pusher(self, app_id: str, push_key: str, user_id: str):
         cmd = RemovePusherCommand(app_id, push_key, user_id)
         self.send_command(cmd)
 
-    def send_invalidate_cache(self, cache_func: Callable, keys: tuple):
-        """Poke the master to invalidate a cache.
-        """
-        cmd = InvalidateCacheCommand(cache_func.__name__, keys)
-        self.send_command(cmd)
-
     def send_user_ip(
         self,
         user_id: str,
diff --git a/synapse/replication/tcp/redis.py b/synapse/replication/tcp/redis.py
index 55bfa71dfdc0..e776b6318307 100644
--- a/synapse/replication/tcp/redis.py
+++ b/synapse/replication/tcp/redis.py
@@ -70,7 +70,6 @@ def connectionMade(self):
         logger.info("Connected to redis")
         super().connectionMade()
         run_as_background_process("subscribe-replication", self._send_subscribe)
-        self.handler.new_connection(self)
 
     async def _send_subscribe(self):
         # it's important to make sure that we only send the REPLICATE command once we
@@ -81,9 +80,15 @@ async def _send_subscribe(self):
         logger.info(
             "Successfully subscribed to redis stream, sending REPLICATE command"
         )
+        self.handler.new_connection(self)
         await self._async_send_command(ReplicateCommand())
         logger.info("REPLICATE successfully sent")
 
+        # We send out our positions when there is a new connection in case the
+        # other side missed updates. We do this for Redis connections as the
+        # otherside won't know we've connected and so won't issue a REPLICATE.
+        self.handler.send_positions_to_connection(self)
+
     def messageReceived(self, pattern: str, channel: str, message: str):
         """Received a message from redis.
         """
diff --git a/synapse/replication/tcp/resource.py b/synapse/replication/tcp/resource.py
index 33d2f589ac36..41569305df1a 100644
--- a/synapse/replication/tcp/resource.py
+++ b/synapse/replication/tcp/resource.py
@@ -17,7 +17,6 @@
 
 import logging
 import random
-from typing import Dict, List
 
 from prometheus_client import Counter
 
@@ -25,7 +24,6 @@
 
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.replication.tcp.protocol import ServerReplicationStreamProtocol
-from synapse.replication.tcp.streams import STREAMS_MAP, FederationStream, Stream
 from synapse.util.metrics import Measure
 
 stream_updates_counter = Counter(
@@ -71,26 +69,11 @@ def __init__(self, hs):
         self.store = hs.get_datastore()
         self.clock = hs.get_clock()
         self.notifier = hs.get_notifier()
+        self._instance_name = hs.get_instance_name()
 
         self._replication_torture_level = hs.config.replication_torture_level
 
-        # Work out list of streams that this instance is the source of.
-        self.streams = []  # type: List[Stream]
-        if hs.config.worker_app is None:
-            for stream in STREAMS_MAP.values():
-                if stream == FederationStream and hs.config.send_federation:
-                    # We only support federation stream if federation sending
-                    # hase been disabled on the master.
-                    continue
-
-                self.streams.append(stream(hs))
-
-        self.streams_by_name = {stream.NAME: stream for stream in self.streams}
-
-        # Only bother registering the notifier callback if we have streams to
-        # publish.
-        if self.streams:
-            self.notifier.add_replication_callback(self.on_notifier_poke)
+        self.notifier.add_replication_callback(self.on_notifier_poke)
 
         # Keeps track of whether we are currently checking for updates
         self.is_looping = False
@@ -98,10 +81,8 @@ def __init__(self, hs):
 
         self.command_handler = hs.get_tcp_replication()
 
-    def get_streams(self) -> Dict[str, Stream]:
-        """Get a mapp from stream name to stream instance.
-        """
-        return self.streams_by_name
+        # Set of streams to replicate.
+        self.streams = self.command_handler.get_streams_to_replicate()
 
     def on_notifier_poke(self):
         """Checks if there is actually any new data and sends it to the
@@ -145,7 +126,9 @@ async def _run_notifier_loop(self):
                         random.shuffle(all_streams)
 
                     for stream in all_streams:
-                        if stream.last_token == stream.current_token():
+                        if stream.last_token == stream.current_token(
+                            self._instance_name
+                        ):
                             continue
 
                         if self._replication_torture_level:
@@ -157,7 +140,7 @@ async def _run_notifier_loop(self):
                             "Getting stream: %s: %s -> %s",
                             stream.NAME,
                             stream.last_token,
-                            stream.current_token(),
+                            stream.current_token(self._instance_name),
                         )
                         try:
                             updates, current_token, limited = await stream.get_updates()
diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py
index b0f87c365b18..d42aaff05582 100644
--- a/synapse/replication/tcp/streams/_base.py
+++ b/synapse/replication/tcp/streams/_base.py
@@ -14,14 +14,27 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import heapq
 import logging
 from collections import namedtuple
-from typing import Any, Awaitable, Callable, List, Optional, Tuple
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Awaitable,
+    Callable,
+    List,
+    Optional,
+    Tuple,
+    TypeVar,
+)
 
 import attr
 
 from synapse.replication.http.streams import ReplicationGetStreamUpdates
 
+if TYPE_CHECKING:
+    import synapse.server
+
 logger = logging.getLogger(__name__)
 
 # the number of rows to request from an update_function.
@@ -37,7 +50,7 @@
 # parsing with Stream.parse_row (which turns it into a `ROW_TYPE`). Normally it's
 # just a row from a database query, though this is dependent on the stream in question.
 #
-StreamRow = Tuple
+StreamRow = TypeVar("StreamRow", bound=Tuple)
 
 # The type returned by the update_function of a stream, as well as get_updates(),
 # get_updates_since, etc.
@@ -95,19 +108,25 @@ def parse_row(cls, row: StreamRow):
     def __init__(
         self,
         local_instance_name: str,
-        current_token_function: Callable[[], Token],
+        current_token_function: Callable[[str], Token],
         update_function: UpdateFunction,
     ):
         """Instantiate a Stream
 
-        current_token_function and update_function are callbacks which should be
-        implemented by subclasses.
+        `current_token_function` and `update_function` are callbacks which
+        should be implemented by subclasses.
 
-        current_token_function is called to get the current token of the underlying
-        stream.
+        `current_token_function` takes an instance name, which is a writer to
+        the stream, and returns the position in the stream of the writer (as
+        viewed from the current process). On the writer process this is where
+        the writer has successfully written up to, whereas on other processes
+        this is the position which we have received updates up to over
+        replication. (Note that most streams have a single writer and so their
+        implementations ignore the instance name passed in).
 
-        update_function is called to get updates for this stream between a pair of
-        stream tokens. See the UpdateFunction type definition for more info.
+        `update_function` is called to get updates for this stream between a
+        pair of stream tokens. See the `UpdateFunction` type definition for more
+        info.
 
         Args:
             local_instance_name: The instance name of the current process
@@ -119,13 +138,13 @@ def __init__(
         self.update_function = update_function
 
         # The token from which we last asked for updates
-        self.last_token = self.current_token()
+        self.last_token = self.current_token(self.local_instance_name)
 
     def discard_updates_and_advance(self):
         """Called when the stream should advance but the updates would be discarded,
         e.g. when there are no currently connected workers.
         """
-        self.last_token = self.current_token()
+        self.last_token = self.current_token(self.local_instance_name)
 
     async def get_updates(self) -> StreamUpdateResult:
         """Gets all updates since the last time this function was called (or
@@ -137,7 +156,7 @@ async def get_updates(self) -> StreamUpdateResult:
             position in stream, and `limited` is whether there are more updates
             to fetch.
         """
-        current_token = self.current_token()
+        current_token = self.current_token(self.local_instance_name)
         updates, current_token, limited = await self.get_updates_since(
             self.local_instance_name, self.last_token, current_token
         )
@@ -169,6 +188,16 @@ async def get_updates_since(
         return updates, upto_token, limited
 
 
+def current_token_without_instance(
+    current_token: Callable[[], int]
+) -> Callable[[str], int]:
+    """Takes a current token callback function for a single writer stream
+    that doesn't take an instance name parameter and wraps it in a function that
+    does accept an instance name parameter but ignores it.
+    """
+    return lambda instance_name: current_token()
+
+
 def db_query_to_update_function(
     query_function: Callable[[Token, Token, int], Awaitable[List[tuple]]]
 ) -> UpdateFunction:
@@ -234,7 +263,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_current_backfill_token,
+            current_token_without_instance(store.get_current_backfill_token),
             db_query_to_update_function(store.get_all_new_backfill_event_rows),
         )
 
@@ -270,7 +299,9 @@ def __init__(self, hs):
             update_function = make_http_update_function(hs, self.NAME)
 
         super().__init__(
-            hs.get_instance_name(), store.get_current_presence_token, update_function
+            hs.get_instance_name(),
+            current_token_without_instance(store.get_current_presence_token),
+            update_function,
         )
 
 
@@ -295,7 +326,9 @@ def __init__(self, hs):
             update_function = make_http_update_function(hs, self.NAME)
 
         super().__init__(
-            hs.get_instance_name(), typing_handler.get_current_token, update_function
+            hs.get_instance_name(),
+            current_token_without_instance(typing_handler.get_current_token),
+            update_function,
         )
 
 
@@ -318,7 +351,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_max_receipt_stream_id,
+            current_token_without_instance(store.get_max_receipt_stream_id),
             db_query_to_update_function(store.get_all_updated_receipts),
         )
 
@@ -338,7 +371,7 @@ def __init__(self, hs):
             hs.get_instance_name(), self._current_token, self._update_function
         )
 
-    def _current_token(self) -> int:
+    def _current_token(self, instance_name: str) -> int:
         push_rules_token, _ = self.store.get_push_rules_stream_token()
         return push_rules_token
 
@@ -372,7 +405,7 @@ def __init__(self, hs):
 
         super().__init__(
             hs.get_instance_name(),
-            store.get_pushers_stream_token,
+            current_token_without_instance(store.get_pushers_stream_token),
             db_query_to_update_function(store.get_all_updated_pushers_rows),
         )
 
@@ -401,13 +434,27 @@ class CachesStreamRow:
     ROW_TYPE = CachesStreamRow
 
     def __init__(self, hs):
-        store = hs.get_datastore()
+        self.store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_cache_stream_token,
-            db_query_to_update_function(store.get_all_updated_caches),
+            self.store.get_cache_stream_token,
+            self._update_function,
         )
 
+    async def _update_function(
+        self, instance_name: str, from_token: int, upto_token: int, limit: int
+    ):
+        rows = await self.store.get_all_updated_caches(
+            instance_name, from_token, upto_token, limit
+        )
+        updates = [(row[0], row[1:]) for row in rows]
+        limited = False
+        if len(updates) >= limit:
+            upto_token = updates[-1][0]
+            limited = True
+
+        return updates, upto_token, limited
+
 
 class PublicRoomsStream(Stream):
     """The public rooms list changed
@@ -430,7 +477,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_current_public_room_stream_id,
+            current_token_without_instance(store.get_current_public_room_stream_id),
             db_query_to_update_function(store.get_all_new_public_rooms),
         )
 
@@ -451,7 +498,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_device_stream_token,
+            current_token_without_instance(store.get_device_stream_token),
             db_query_to_update_function(store.get_all_device_list_changes_for_remotes),
         )
 
@@ -469,7 +516,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_to_device_stream_token,
+            current_token_without_instance(store.get_to_device_stream_token),
             db_query_to_update_function(store.get_all_new_device_messages),
         )
 
@@ -489,7 +536,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_max_account_data_stream_id,
+            current_token_without_instance(store.get_max_account_data_stream_id),
             db_query_to_update_function(store.get_all_updated_tags),
         )
 
@@ -499,32 +546,63 @@ class AccountDataStream(Stream):
     """
 
     AccountDataStreamRow = namedtuple(
-        "AccountDataStream", ("user_id", "room_id", "data_type")  # str  # str  # str
+        "AccountDataStream",
+        ("user_id", "room_id", "data_type"),  # str  # Optional[str]  # str
     )
 
     NAME = "account_data"
     ROW_TYPE = AccountDataStreamRow
 
-    def __init__(self, hs):
+    def __init__(self, hs: "synapse.server.HomeServer"):
         self.store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            self.store.get_max_account_data_stream_id,
-            db_query_to_update_function(self._update_function),
+            current_token_without_instance(self.store.get_max_account_data_stream_id),
+            self._update_function,
         )
 
-    async def _update_function(self, from_token, to_token, limit):
-        global_results, room_results = await self.store.get_all_updated_account_data(
-            from_token, from_token, to_token, limit
+    async def _update_function(
+        self, instance_name: str, from_token: int, to_token: int, limit: int
+    ) -> StreamUpdateResult:
+        limited = False
+        global_results = await self.store.get_updated_global_account_data(
+            from_token, to_token, limit
         )
 
-        results = list(room_results)
-        results.extend(
-            (stream_id, user_id, None, account_data_type)
+        # if the global results hit the limit, we'll need to limit the room results to
+        # the same stream token.
+        if len(global_results) >= limit:
+            to_token = global_results[-1][0]
+            limited = True
+
+        room_results = await self.store.get_updated_room_account_data(
+            from_token, to_token, limit
+        )
+
+        # likewise, if the room results hit the limit, limit the global results to
+        # the same stream token.
+        if len(room_results) >= limit:
+            to_token = room_results[-1][0]
+            limited = True
+
+        # convert the global results to the right format, and limit them to the to_token
+        # at the same time
+        global_rows = (
+            (stream_id, (user_id, None, account_data_type))
             for stream_id, user_id, account_data_type in global_results
+            if stream_id <= to_token
+        )
+
+        # we know that the room_results are already limited to `to_token` so no need
+        # for a check on `stream_id` here.
+        room_rows = (
+            (stream_id, (user_id, room_id, account_data_type))
+            for stream_id, user_id, room_id, account_data_type in room_results
         )
 
-        return results
+        # we need to return a sorted list, so merge them together.
+        updates = list(heapq.merge(room_rows, global_rows))
+        return updates, to_token, limited
 
 
 class GroupServerStream(Stream):
@@ -540,7 +618,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_group_stream_token,
+            current_token_without_instance(store.get_group_stream_token),
             db_query_to_update_function(store.get_all_groups_changes),
         )
 
@@ -558,7 +636,7 @@ def __init__(self, hs):
         store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            store.get_device_stream_token,
+            current_token_without_instance(store.get_device_stream_token),
             db_query_to_update_function(
                 store.get_all_user_signature_changes_for_remotes
             ),
diff --git a/synapse/replication/tcp/streams/events.py b/synapse/replication/tcp/streams/events.py
index 890e75d8271d..f3703903314d 100644
--- a/synapse/replication/tcp/streams/events.py
+++ b/synapse/replication/tcp/streams/events.py
@@ -20,7 +20,7 @@
 
 import attr
 
-from ._base import Stream, StreamUpdateResult, Token
+from ._base import Stream, StreamUpdateResult, Token, current_token_without_instance
 
 
 """Handling of the 'events' replication stream
@@ -119,7 +119,7 @@ def __init__(self, hs):
         self._store = hs.get_datastore()
         super().__init__(
             hs.get_instance_name(),
-            self._store.get_current_events_token,
+            current_token_without_instance(self._store.get_current_events_token),
             self._update_function,
         )
 
diff --git a/synapse/replication/tcp/streams/federation.py b/synapse/replication/tcp/streams/federation.py
index e8bd52e38952..9bcd13b00989 100644
--- a/synapse/replication/tcp/streams/federation.py
+++ b/synapse/replication/tcp/streams/federation.py
@@ -15,7 +15,11 @@
 # limitations under the License.
 from collections import namedtuple
 
-from synapse.replication.tcp.streams._base import Stream, db_query_to_update_function
+from synapse.replication.tcp.streams._base import (
+    Stream,
+    current_token_without_instance,
+    make_http_update_function,
+)
 
 
 class FederationStream(Stream):
@@ -35,21 +39,35 @@ class FederationStream(Stream):
     ROW_TYPE = FederationStreamRow
 
     def __init__(self, hs):
-        # Not all synapse instances will have a federation sender instance,
-        # whether that's a `FederationSender` or a `FederationRemoteSendQueue`,
-        # so we stub the stream out when that is the case.
-        if hs.config.worker_app is None or hs.should_send_federation():
+        if hs.config.worker_app is None:
+            # master process: get updates from the FederationRemoteSendQueue.
+            # (if the master is configured to send federation itself, federation_sender
+            # will be a real FederationSender, which has stubs for current_token and
+            # get_replication_rows.)
             federation_sender = hs.get_federation_sender()
-            current_token = federation_sender.get_current_token
-            update_function = db_query_to_update_function(
-                federation_sender.get_replication_rows
+            current_token = current_token_without_instance(
+                federation_sender.get_current_token
             )
+            update_function = federation_sender.get_replication_rows
+
+        elif hs.should_send_federation():
+            # federation sender: Query master process
+            update_function = make_http_update_function(hs, self.NAME)
+            current_token = self._stub_current_token
+
         else:
-            current_token = lambda: 0
+            # other worker: stub out the update function (we're not interested in
+            # any updates so when we get a POSITION we do nothing)
             update_function = self._stub_update_function
+            current_token = self._stub_current_token
 
         super().__init__(hs.get_instance_name(), current_token, update_function)
 
+    @staticmethod
+    def _stub_current_token(instance_name: str) -> int:
+        # dummy current-token method for use on workers
+        return 0
+
     @staticmethod
     async def _stub_update_function(instance_name, from_token, upto_token, limit):
         return [], upto_token, False
diff --git a/synapse/res/templates/notice_expiry.html b/synapse/res/templates/notice_expiry.html
index f0d7c66e1b13..6b94d8c367c9 100644
--- a/synapse/res/templates/notice_expiry.html
+++ b/synapse/res/templates/notice_expiry.html
@@ -30,7 +30,7 @@
                         <tr>
                           <td colspan="2">
                             <div class="noticetext">Your account will expire on {{ expiration_ts|format_ts("%d-%m-%Y") }}. This means that you will lose access to your account after this date.</div>
-                            <div class="noticetext">To extend the validity of your account, please click on the link bellow (or copy and paste it into a new browser tab):</div>
+                            <div class="noticetext">To extend the validity of your account, please click on the link below (or copy and paste it into a new browser tab):</div>
                             <div class="noticetext"><a href="{{ url }}">{{ url }}</a></div>
                           </td>
                         </tr>
diff --git a/synapse/res/templates/notice_expiry.txt b/synapse/res/templates/notice_expiry.txt
index 41f1c4279cb0..4ec27e88318b 100644
--- a/synapse/res/templates/notice_expiry.txt
+++ b/synapse/res/templates/notice_expiry.txt
@@ -2,6 +2,6 @@ Hi {{ display_name }},
 
 Your account will expire on {{ expiration_ts|format_ts("%d-%m-%Y") }}. This means that you will lose access to your account after this date.
 
-To extend the validity of your account, please click on the link bellow (or copy and paste it to a new browser tab):
+To extend the validity of your account, please click on the link below (or copy and paste it to a new browser tab):
 
 {{ url }}
diff --git a/synapse/res/templates/sso_error.html b/synapse/res/templates/sso_error.html
new file mode 100644
index 000000000000..43a211386bec
--- /dev/null
+++ b/synapse/res/templates/sso_error.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>SSO error</title>
+</head>
+<body>
+    <p>Oops! Something went wrong during authentication.</p>
+    <p>
+        Try logging in again from your Matrix client and if the problem persists
+        please contact the server's administrator.
+    </p>
+    <p>Error: <code>{{ error }}</code></p>
+    {% if error_description %}
+    <pre><code>{{ error_description }}</code></pre>
+    {% endif %}
+</body>
+</html>
diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index ed70d448a141..6b85148a32fb 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -32,6 +32,7 @@
 from synapse.rest.admin.rooms import (
     JoinRoomAliasServlet,
     ListRoomRestServlet,
+    RoomRestServlet,
     ShutdownRoomRestServlet,
 )
 from synapse.rest.admin.server_notice_servlet import SendServerNoticeServlet
@@ -193,6 +194,7 @@ def register_servlets(hs, http_server):
     """
     register_servlets_for_client_rest_resource(hs, http_server)
     ListRoomRestServlet(hs).register(http_server)
+    RoomRestServlet(hs).register(http_server)
     JoinRoomAliasServlet(hs).register(http_server)
     PurgeRoomServlet(hs).register(http_server)
     SendServerNoticeServlet(hs).register(http_server)
diff --git a/synapse/rest/admin/rooms.py b/synapse/rest/admin/rooms.py
index d1bdb641115d..7d4000198866 100644
--- a/synapse/rest/admin/rooms.py
+++ b/synapse/rest/admin/rooms.py
@@ -26,6 +26,7 @@
 )
 from synapse.rest.admin._base import (
     admin_patterns,
+    assert_requester_is_admin,
     assert_user_is_admin,
     historical_admin_path_patterns,
 )
@@ -169,7 +170,7 @@ class ListRoomRestServlet(RestServlet):
     in a dictionary containing room information. Supports pagination.
     """
 
-    PATTERNS = admin_patterns("/rooms")
+    PATTERNS = admin_patterns("/rooms$")
 
     def __init__(self, hs):
         self.store = hs.get_datastore()
@@ -253,6 +254,29 @@ async def on_GET(self, request):
         return 200, response
 
 
+class RoomRestServlet(RestServlet):
+    """Get room details.
+
+    TODO: Add on_POST to allow room creation without joining the room
+    """
+
+    PATTERNS = admin_patterns("/rooms/(?P<room_id>[^/]+)$")
+
+    def __init__(self, hs):
+        self.hs = hs
+        self.auth = hs.get_auth()
+        self.store = hs.get_datastore()
+
+    async def on_GET(self, request, room_id):
+        await assert_requester_is_admin(self.auth, request)
+
+        ret = await self.store.get_room_with_stats(room_id)
+        if not ret:
+            raise NotFoundError("Room not found")
+
+        return 200, ret
+
+
 class JoinRoomAliasServlet(RestServlet):
 
     PATTERNS = admin_patterns("/join/(?P<room_identifier>[^/]*)")
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index 326682fbdb67..e7f6928c859d 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -222,8 +222,14 @@ async def on_PUT(self, request, user_id):
                 else:
                     new_password = body["password"]
                     logout_devices = True
+
+                    new_password_hash = await self.auth_handler.hash(new_password)
+
                     await self.set_password_handler.set_password(
-                        target_user.to_string(), new_password, logout_devices, requester
+                        target_user.to_string(),
+                        new_password_hash,
+                        logout_devices,
+                        requester,
                     )
 
             if "deactivated" in body:
@@ -523,6 +529,7 @@ def __init__(self, hs):
         self.store = hs.get_datastore()
         self.hs = hs
         self.auth = hs.get_auth()
+        self.auth_handler = hs.get_auth_handler()
         self._set_password_handler = hs.get_set_password_handler()
 
     async def on_POST(self, request, target_user_id):
@@ -539,8 +546,10 @@ async def on_POST(self, request, target_user_id):
         new_password = params["new_password"]
         logout_devices = params.get("logout_devices", True)
 
+        new_password_hash = await self.auth_handler.hash(new_password)
+
         await self._set_password_handler.set_password(
-            target_user_id, new_password, logout_devices, requester
+            target_user_id, new_password_hash, logout_devices, requester
         )
         return 200, {}
 
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 4de2f97d06c2..d89b2e5532fa 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -83,6 +83,7 @@ def __init__(self, hs):
         self.jwt_algorithm = hs.config.jwt_algorithm
         self.saml2_enabled = hs.config.saml2_enabled
         self.cas_enabled = hs.config.cas_enabled
+        self.oidc_enabled = hs.config.oidc_enabled
         self.auth_handler = self.hs.get_auth_handler()
         self.registration_handler = hs.get_registration_handler()
         self.handlers = hs.get_handlers()
@@ -96,9 +97,7 @@ def on_GET(self, request):
         flows = []
         if self.jwt_enabled:
             flows.append({"type": LoginRestServlet.JWT_TYPE})
-        if self.saml2_enabled:
-            flows.append({"type": LoginRestServlet.SSO_TYPE})
-            flows.append({"type": LoginRestServlet.TOKEN_TYPE})
+
         if self.cas_enabled:
             flows.append({"type": LoginRestServlet.SSO_TYPE})
 
@@ -114,6 +113,11 @@ def on_GET(self, request):
             # fall back to the fallback API if they don't understand one of the
             # login flow types returned.
             flows.append({"type": LoginRestServlet.TOKEN_TYPE})
+        elif self.saml2_enabled:
+            flows.append({"type": LoginRestServlet.SSO_TYPE})
+            flows.append({"type": LoginRestServlet.TOKEN_TYPE})
+        elif self.oidc_enabled:
+            flows.append({"type": LoginRestServlet.SSO_TYPE})
 
         flows.extend(
             ({"type": t} for t in self.auth_handler.get_supported_login_types())
@@ -397,19 +401,22 @@ class BaseSSORedirectServlet(RestServlet):
 
     PATTERNS = client_patterns("/login/(cas|sso)/redirect", v1=True)
 
-    def on_GET(self, request: SynapseRequest):
+    async def on_GET(self, request: SynapseRequest):
         args = request.args
         if b"redirectUrl" not in args:
             return 400, "Redirect URL not specified for SSO auth"
         client_redirect_url = args[b"redirectUrl"][0]
-        sso_url = self.get_sso_url(client_redirect_url)
+        sso_url = await self.get_sso_url(request, client_redirect_url)
         request.redirect(sso_url)
         finish_request(request)
 
-    def get_sso_url(self, client_redirect_url: bytes) -> bytes:
+    async def get_sso_url(
+        self, request: SynapseRequest, client_redirect_url: bytes
+    ) -> bytes:
         """Get the URL to redirect to, to perform SSO auth
 
         Args:
+            request: The client request to redirect.
             client_redirect_url: the URL that we should redirect the
                 client to when everything is done
 
@@ -424,7 +431,9 @@ class CasRedirectServlet(BaseSSORedirectServlet):
     def __init__(self, hs):
         self._cas_handler = hs.get_cas_handler()
 
-    def get_sso_url(self, client_redirect_url: bytes) -> bytes:
+    async def get_sso_url(
+        self, request: SynapseRequest, client_redirect_url: bytes
+    ) -> bytes:
         return self._cas_handler.get_redirect_url(
             {"redirectUrl": client_redirect_url}
         ).encode("ascii")
@@ -461,10 +470,28 @@ class SAMLRedirectServlet(BaseSSORedirectServlet):
     def __init__(self, hs):
         self._saml_handler = hs.get_saml_handler()
 
-    def get_sso_url(self, client_redirect_url: bytes) -> bytes:
+    async def get_sso_url(
+        self, request: SynapseRequest, client_redirect_url: bytes
+    ) -> bytes:
         return self._saml_handler.handle_redirect_request(client_redirect_url)
 
 
+class OIDCRedirectServlet(BaseSSORedirectServlet):
+    """Implementation for /login/sso/redirect for the OIDC login flow."""
+
+    PATTERNS = client_patterns("/login/sso/redirect", v1=True)
+
+    def __init__(self, hs):
+        self._oidc_handler = hs.get_oidc_handler()
+
+    async def get_sso_url(
+        self, request: SynapseRequest, client_redirect_url: bytes
+    ) -> bytes:
+        return await self._oidc_handler.handle_redirect_request(
+            request, client_redirect_url
+        )
+
+
 def register_servlets(hs, http_server):
     LoginRestServlet(hs).register(http_server)
     if hs.config.cas_enabled:
@@ -472,3 +499,5 @@ def register_servlets(hs, http_server):
         CasTicketServlet(hs).register(http_server)
     elif hs.config.saml2_enabled:
         SAMLRedirectServlet(hs).register(http_server)
+    elif hs.config.oidc_enabled:
+        OIDCRedirectServlet(hs).register(http_server)
diff --git a/synapse/rest/client/v1/logout.py b/synapse/rest/client/v1/logout.py
index 1cf3caf832f2..b0c30b65beac 100644
--- a/synapse/rest/client/v1/logout.py
+++ b/synapse/rest/client/v1/logout.py
@@ -34,10 +34,10 @@ def on_OPTIONS(self, request):
         return 200, {}
 
     async def on_POST(self, request):
-        requester = await self.auth.get_user_by_req(request)
+        requester = await self.auth.get_user_by_req(request, allow_expired=True)
 
         if requester.device_id is None:
-            # the acccess token wasn't associated with a device.
+            # The access token wasn't associated with a device.
             # Just delete the access token
             access_token = self.auth.get_access_token_from_request(request)
             await self._auth_handler.delete_access_token(access_token)
@@ -62,7 +62,7 @@ def on_OPTIONS(self, request):
         return 200, {}
 
     async def on_POST(self, request):
-        requester = await self.auth.get_user_by_req(request)
+        requester = await self.auth.get_user_by_req(request, allow_expired=True)
         user_id = requester.user.to_string()
 
         # first delete all of the user's devices
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 1bd023477902..d4f721b6b989 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -220,12 +220,27 @@ def __init__(self, hs):
         self.auth = hs.get_auth()
         self.auth_handler = hs.get_auth_handler()
         self.datastore = self.hs.get_datastore()
+        self.password_policy_handler = hs.get_password_policy_handler()
         self._set_password_handler = hs.get_set_password_handler()
 
     @interactive_auth_handler
     async def on_POST(self, request):
         body = parse_json_object_from_request(request)
 
+        # we do basic sanity checks here because the auth layer will store these
+        # in sessions. Pull out the new password provided to us.
+        if "new_password" in body:
+            new_password = body.pop("new_password")
+            if not isinstance(new_password, str) or len(new_password) > 512:
+                raise SynapseError(400, "Invalid password")
+            self.password_policy_handler.validate_password(new_password)
+
+            # If the password is valid, hash it and store it back on the body.
+            # This ensures that only the hashed password is handled everywhere.
+            if "new_password_hash" in body:
+                raise SynapseError(400, "Unexpected property: new_password_hash")
+            body["new_password_hash"] = await self.auth_handler.hash(new_password)
+
         # there are two possibilities here. Either the user does not have an
         # access token, and needs to do a password reset; or they have one and
         # need to validate their identity.
@@ -276,12 +291,12 @@ async def on_POST(self, request):
                 logger.error("Auth succeeded but no known type! %r", result.keys())
                 raise SynapseError(500, "", Codes.UNKNOWN)
 
-        assert_params_in_dict(params, ["new_password"])
-        new_password = params["new_password"]
+        assert_params_in_dict(params, ["new_password_hash"])
+        new_password_hash = params["new_password_hash"]
         logout_devices = params.get("logout_devices", True)
 
         await self._set_password_handler.set_password(
-            user_id, new_password, logout_devices, requester
+            user_id, new_password_hash, logout_devices, requester
         )
 
         return 200, {}
diff --git a/synapse/rest/client/v2_alpha/auth.py b/synapse/rest/client/v2_alpha/auth.py
index 24dd3d3e96d1..7bca1326d54f 100644
--- a/synapse/rest/client/v2_alpha/auth.py
+++ b/synapse/rest/client/v2_alpha/auth.py
@@ -131,14 +131,19 @@ def __init__(self, hs):
         self.registration_handler = hs.get_registration_handler()
 
         # SSO configuration.
-        self._saml_enabled = hs.config.saml2_enabled
-        if self._saml_enabled:
-            self._saml_handler = hs.get_saml_handler()
         self._cas_enabled = hs.config.cas_enabled
         if self._cas_enabled:
             self._cas_handler = hs.get_cas_handler()
             self._cas_server_url = hs.config.cas_server_url
             self._cas_service_url = hs.config.cas_service_url
+        self._saml_enabled = hs.config.saml2_enabled
+        if self._saml_enabled:
+            self._saml_handler = hs.get_saml_handler()
+        self._oidc_enabled = hs.config.oidc_enabled
+        if self._oidc_enabled:
+            self._oidc_handler = hs.get_oidc_handler()
+            self._cas_server_url = hs.config.cas_server_url
+            self._cas_service_url = hs.config.cas_service_url
 
     async def on_GET(self, request, stagetype):
         session = parse_string(request, "session")
@@ -172,11 +177,17 @@ async def on_GET(self, request, stagetype):
                 )
 
             elif self._saml_enabled:
-                client_redirect_url = ""
+                client_redirect_url = b""
                 sso_redirect_url = self._saml_handler.handle_redirect_request(
                     client_redirect_url, session
                 )
 
+            elif self._oidc_enabled:
+                client_redirect_url = b""
+                sso_redirect_url = await self._oidc_handler.handle_redirect_request(
+                    request, client_redirect_url, session
+                )
+
             else:
                 raise SynapseError(400, "Homeserver not configured for SSO.")
 
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index c26927f27b9e..addd4cae1906 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -431,8 +431,8 @@ async def on_POST(self, request):
                 raise SynapseError(400, "Invalid password")
             self.password_policy_handler.validate_password(password)
 
-            # If the password is valid, hash it and store it back on the request.
-            # This ensures the hashed password is handled everywhere.
+            # If the password is valid, hash it and store it back on the body.
+            # This ensures that only the hashed password is handled everywhere.
             if "password_hash" in body:
                 raise SynapseError(400, "Unexpected property: password_hash")
             body["password_hash"] = await self.auth_handler.hash(password)
diff --git a/synapse/rest/media/v1/_base.py b/synapse/rest/media/v1/_base.py
index 503f2bed98e1..36897772662b 100644
--- a/synapse/rest/media/v1/_base.py
+++ b/synapse/rest/media/v1/_base.py
@@ -17,7 +17,6 @@
 import logging
 import os
 
-from six import PY3
 from six.moves import urllib
 
 from twisted.internet import defer
@@ -324,23 +323,15 @@ def get_filename_from_headers(headers):
             upload_name_utf8 = upload_name_utf8[7:]
             # We have a filename*= section. This MUST be ASCII, and any UTF-8
             # bytes are %-quoted.
-            if PY3:
-                try:
-                    # Once it is decoded, we can then unquote the %-encoded
-                    # parts strictly into a unicode string.
-                    upload_name = urllib.parse.unquote(
-                        upload_name_utf8.decode("ascii"), errors="strict"
-                    )
-                except UnicodeDecodeError:
-                    # Incorrect UTF-8.
-                    pass
-            else:
-                # On Python 2, we first unquote the %-encoded parts and then
-                # decode it strictly using UTF-8.
-                try:
-                    upload_name = urllib.parse.unquote(upload_name_utf8).decode("utf8")
-                except UnicodeDecodeError:
-                    pass
+            try:
+                # Once it is decoded, we can then unquote the %-encoded
+                # parts strictly into a unicode string.
+                upload_name = urllib.parse.unquote(
+                    upload_name_utf8.decode("ascii"), errors="strict"
+                )
+            except UnicodeDecodeError:
+                # Incorrect UTF-8.
+                pass
 
     # If there isn't check for an ascii name.
     if not upload_name:
diff --git a/synapse/rest/oidc/__init__.py b/synapse/rest/oidc/__init__.py
new file mode 100644
index 000000000000..d958dd65bba2
--- /dev/null
+++ b/synapse/rest/oidc/__init__.py
@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Quentin Gliech
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+
+from twisted.web.resource import Resource
+
+from synapse.rest.oidc.callback_resource import OIDCCallbackResource
+
+logger = logging.getLogger(__name__)
+
+
+class OIDCResource(Resource):
+    def __init__(self, hs):
+        Resource.__init__(self)
+        self.putChild(b"callback", OIDCCallbackResource(hs))
diff --git a/synapse/rest/oidc/callback_resource.py b/synapse/rest/oidc/callback_resource.py
new file mode 100644
index 000000000000..c03194f00178
--- /dev/null
+++ b/synapse/rest/oidc/callback_resource.py
@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Quentin Gliech
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+
+from synapse.http.server import DirectServeResource, wrap_html_request_handler
+
+logger = logging.getLogger(__name__)
+
+
+class OIDCCallbackResource(DirectServeResource):
+    isLeaf = 1
+
+    def __init__(self, hs):
+        super().__init__()
+        self._oidc_handler = hs.get_oidc_handler()
+
+    @wrap_html_request_handler
+    async def _async_render_GET(self, request):
+        return await self._oidc_handler.handle_oidc_callback(request)
diff --git a/synapse/server.py b/synapse/server.py
index bf97a16c099f..c530f1aa1ad9 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -204,6 +204,7 @@ def build_DEPENDENCY(self)
         "account_validity_handler",
         "cas_handler",
         "saml_handler",
+        "oidc_handler",
         "event_client_serializer",
         "password_policy_handler",
         "storage",
@@ -562,6 +563,11 @@ def build_saml_handler(self):
 
         return SamlHandler(self)
 
+    def build_oidc_handler(self):
+        from synapse.handlers.oidc_handler import OidcHandler
+
+        return OidcHandler(self)
+
     def build_event_client_serializer(self):
         return EventClientSerializer(self)
 
@@ -575,7 +581,7 @@ def build_replication_streamer(self) -> ReplicationStreamer:
         return ReplicationStreamer(self)
 
     def build_replication_data_handler(self):
-        return ReplicationDataHandler(self.get_datastore())
+        return ReplicationDataHandler(self)
 
     def remove_pusher(self, app_id, push_key, user_id):
         return self.get_pusherpool().remove_pusher(app_id, push_key, user_id)
diff --git a/synapse/server.pyi b/synapse/server.pyi
index 18043a259317..9e7fad7e6e53 100644
--- a/synapse/server.pyi
+++ b/synapse/server.pyi
@@ -13,11 +13,13 @@ import synapse.handlers.device
 import synapse.handlers.e2e_keys
 import synapse.handlers.message
 import synapse.handlers.presence
+import synapse.handlers.register
 import synapse.handlers.room
 import synapse.handlers.room_member
 import synapse.handlers.set_password
 import synapse.http.client
 import synapse.notifier
+import synapse.push.pusherpool
 import synapse.replication.tcp.client
 import synapse.replication.tcp.handler
 import synapse.rest.media.v1.media_repository
@@ -128,3 +130,9 @@ class HomeServer(object):
         pass
     def get_storage(self) -> synapse.storage.Storage:
         pass
+    def get_registration_handler(self) -> synapse.handlers.register.RegistrationHandler:
+        pass
+    def get_macaroon_generator(self) -> synapse.handlers.auth.MacaroonGenerator:
+        pass
+    def get_pusherpool(self) -> synapse.push.pusherpool.PusherPool:
+        pass
diff --git a/synapse/state/__init__.py b/synapse/state/__init__.py
index 4afefc6b1d2e..2fa529fcd087 100644
--- a/synapse/state/__init__.py
+++ b/synapse/state/__init__.py
@@ -35,7 +35,6 @@
 from synapse.storage.data_stores.main.events_worker import EventRedactBehaviour
 from synapse.types import StateMap
 from synapse.util.async_helpers import Linearizer
-from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.metrics import Measure, measure_func
 
@@ -53,7 +52,6 @@
 KeyStateTuple = namedtuple("KeyStateTuple", ("context", "type", "state_key"))
 
 
-SIZE_OF_CACHE = 100000 * get_cache_factor_for("state_cache")
 EVICTION_TIMEOUT_SECONDS = 60 * 60
 
 
@@ -447,7 +445,7 @@ def __init__(self, hs):
         self._state_cache = ExpiringCache(
             cache_name="state_cache",
             clock=self.clock,
-            max_len=SIZE_OF_CACHE,
+            max_len=100000,
             expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
             iterable=True,
             reset_expiry_on_get=True,
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 13de5f1f62b1..bfce541ca7ad 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -19,9 +19,6 @@
 from abc import ABCMeta
 from typing import Any, Optional
 
-from six import PY2
-from six.moves import builtins
-
 from canonicaljson import json
 
 from synapse.storage.database import LoggingTransaction  # noqa: F401
@@ -47,6 +44,9 @@ def __init__(self, database: Database, db_conn, hs):
         self.db = database
         self.rand = random.SystemRandom()
 
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
+        pass
+
     def _invalidate_state_caches(self, room_id, members_changed):
         """Invalidates caches that are based on the current state, but does
         not stream invalidations down replication.
@@ -100,11 +100,6 @@ def db_to_json(db_content):
     if isinstance(db_content, memoryview):
         db_content = db_content.tobytes()
 
-    # psycopg2 on Python 2 returns buffer objects, which we need to cast to
-    # bytes to decode
-    if PY2 and isinstance(db_content, builtins.buffer):
-        db_content = bytes(db_content)
-
     # Decode it to a Unicode string before feeding it to json.loads, so we
     # consistenty get a Unicode-containing object out.
     if isinstance(db_content, (bytes, bytearray)):
diff --git a/synapse/storage/data_stores/__init__.py b/synapse/storage/data_stores/__init__.py
index e1d03429ca04..791961b296dc 100644
--- a/synapse/storage/data_stores/__init__.py
+++ b/synapse/storage/data_stores/__init__.py
@@ -15,6 +15,7 @@
 
 import logging
 
+from synapse.storage.data_stores.main.events import PersistEventsStore
 from synapse.storage.data_stores.state import StateGroupDataStore
 from synapse.storage.database import Database, make_conn
 from synapse.storage.engines import create_engine
@@ -39,6 +40,7 @@ def __init__(self, main_store_class, hs):
         self.databases = []
         self.main = None
         self.state = None
+        self.persist_events = None
 
         for database_config in hs.config.database.databases:
             db_name = database_config.name
@@ -64,6 +66,13 @@ def __init__(self, main_store_class, hs):
 
                     self.main = main_store_class(database, db_conn, hs)
 
+                    # If we're on a process that can persist events (currently
+                    # master), also instantiate a `PersistEventsStore`
+                    if hs.config.worker.worker_app is None:
+                        self.persist_events = PersistEventsStore(
+                            hs, database, self.main
+                        )
+
                 if "state" in database_config.data_stores:
                     logger.info("Starting 'state' data store")
 
diff --git a/synapse/storage/data_stores/main/__init__.py b/synapse/storage/data_stores/main/__init__.py
index ceba10882c7d..4b4763c70172 100644
--- a/synapse/storage/data_stores/main/__init__.py
+++ b/synapse/storage/data_stores/main/__init__.py
@@ -24,15 +24,16 @@
 from synapse.storage.database import Database
 from synapse.storage.engines import PostgresEngine
 from synapse.storage.util.id_generators import (
-    ChainedIdGenerator,
     IdGenerator,
+    MultiWriterIdGenerator,
     StreamIdGenerator,
 )
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 from .account_data import AccountDataStore
 from .appservice import ApplicationServiceStore, ApplicationServiceTransactionStore
-from .cache import CacheInvalidationStore
+from .cache import CacheInvalidationWorkerStore
+from .censor_events import CensorEventsStore
 from .client_ips import ClientIpStore
 from .deviceinbox import DeviceInboxStore
 from .devices import DeviceStore
@@ -41,16 +42,17 @@
 from .end_to_end_keys import EndToEndKeyStore
 from .event_federation import EventFederationStore
 from .event_push_actions import EventPushActionsStore
-from .events import EventsStore
 from .events_bg_updates import EventsBackgroundUpdatesStore
 from .filtering import FilteringStore
 from .group_server import GroupServerStore
 from .keys import KeyStore
 from .media_repository import MediaRepositoryStore
+from .metrics import ServerMetricsStore
 from .monthly_active_users import MonthlyActiveUsersStore
 from .openid import OpenIdStore
 from .presence import PresenceStore, UserPresenceState
 from .profile import ProfileStore
+from .purge_events import PurgeEventsStore
 from .push_rule import PushRuleStore
 from .pusher import PusherStore
 from .receipts import ReceiptsStore
@@ -87,7 +89,7 @@ class DataStore(
     StateStore,
     SignatureStore,
     ApplicationServiceStore,
-    EventsStore,
+    PurgeEventsStore,
     EventFederationStore,
     MediaRepositoryStore,
     RejectionsStore,
@@ -112,27 +114,16 @@ class DataStore(
     MonthlyActiveUsersStore,
     StatsStore,
     RelationsStore,
-    CacheInvalidationStore,
+    CensorEventsStore,
     UIAuthStore,
+    CacheInvalidationWorkerStore,
+    ServerMetricsStore,
 ):
     def __init__(self, database: Database, db_conn, hs):
         self.hs = hs
         self._clock = hs.get_clock()
         self.database_engine = database.engine
 
-        self._stream_id_gen = StreamIdGenerator(
-            db_conn,
-            "events",
-            "stream_ordering",
-            extra_tables=[("local_invites", "stream_id")],
-        )
-        self._backfill_id_gen = StreamIdGenerator(
-            db_conn,
-            "events",
-            "stream_ordering",
-            step=-1,
-            extra_tables=[("ex_outlier_stream", "event_stream_ordering")],
-        )
         self._presence_id_gen = StreamIdGenerator(
             db_conn, "presence_stream", "stream_id"
         )
@@ -159,9 +150,6 @@ def __init__(self, database: Database, db_conn, hs):
         self._event_reports_id_gen = IdGenerator(db_conn, "event_reports", "id")
         self._push_rule_id_gen = IdGenerator(db_conn, "push_rules", "id")
         self._push_rules_enable_id_gen = IdGenerator(db_conn, "push_rules_enable", "id")
-        self._push_rules_stream_id_gen = ChainedIdGenerator(
-            self._stream_id_gen, db_conn, "push_rules_stream", "stream_id"
-        )
         self._pushers_id_gen = StreamIdGenerator(
             db_conn, "pushers", "id", extra_tables=[("deleted_pushers", "stream_id")]
         )
@@ -170,8 +158,14 @@ def __init__(self, database: Database, db_conn, hs):
         )
 
         if isinstance(self.database_engine, PostgresEngine):
-            self._cache_id_gen = StreamIdGenerator(
-                db_conn, "cache_invalidation_stream", "stream_id"
+            self._cache_id_gen = MultiWriterIdGenerator(
+                db_conn,
+                database,
+                instance_name="master",
+                table="cache_invalidation_stream_by_instance",
+                instance_column="instance_name",
+                id_column="stream_id",
+                sequence_name="cache_invalidation_stream_seq",
             )
         else:
             self._cache_id_gen = None
diff --git a/synapse/storage/data_stores/main/account_data.py b/synapse/storage/data_stores/main/account_data.py
index 46b494b33465..f9eef1b78ecc 100644
--- a/synapse/storage/data_stores/main/account_data.py
+++ b/synapse/storage/data_stores/main/account_data.py
@@ -16,6 +16,7 @@
 
 import abc
 import logging
+from typing import List, Tuple
 
 from canonicaljson import json
 
@@ -175,41 +176,64 @@ def get_account_data_for_room_and_type_txn(txn):
             "get_account_data_for_room_and_type", get_account_data_for_room_and_type_txn
         )
 
-    def get_all_updated_account_data(
-        self, last_global_id, last_room_id, current_id, limit
-    ):
-        """Get all the client account_data that has changed on the server
+    async def get_updated_global_account_data(
+        self, last_id: int, current_id: int, limit: int
+    ) -> List[Tuple[int, str, str]]:
+        """Get the global account_data that has changed, for the account_data stream
+
         Args:
-            last_global_id(int): The position to fetch from for top level data
-            last_room_id(int): The position to fetch from for per room data
-            current_id(int): The position to fetch up to.
+            last_id: the last stream_id from the previous batch.
+            current_id: the maximum stream_id to return up to
+            limit: the maximum number of rows to return
+
         Returns:
-            A deferred pair of lists of tuples of stream_id int, user_id string,
-            room_id string, and type string.
+            A list of tuples of stream_id int, user_id string,
+            and type string.
         """
-        if last_room_id == current_id and last_global_id == current_id:
-            return defer.succeed(([], []))
+        if last_id == current_id:
+            return []
 
-        def get_updated_account_data_txn(txn):
+        def get_updated_global_account_data_txn(txn):
             sql = (
                 "SELECT stream_id, user_id, account_data_type"
                 " FROM account_data WHERE ? < stream_id AND stream_id <= ?"
                 " ORDER BY stream_id ASC LIMIT ?"
             )
-            txn.execute(sql, (last_global_id, current_id, limit))
-            global_results = txn.fetchall()
+            txn.execute(sql, (last_id, current_id, limit))
+            return txn.fetchall()
+
+        return await self.db.runInteraction(
+            "get_updated_global_account_data", get_updated_global_account_data_txn
+        )
+
+    async def get_updated_room_account_data(
+        self, last_id: int, current_id: int, limit: int
+    ) -> List[Tuple[int, str, str, str]]:
+        """Get the global account_data that has changed, for the account_data stream
 
+        Args:
+            last_id: the last stream_id from the previous batch.
+            current_id: the maximum stream_id to return up to
+            limit: the maximum number of rows to return
+
+        Returns:
+            A list of tuples of stream_id int, user_id string,
+            room_id string and type string.
+        """
+        if last_id == current_id:
+            return []
+
+        def get_updated_room_account_data_txn(txn):
             sql = (
                 "SELECT stream_id, user_id, room_id, account_data_type"
                 " FROM room_account_data WHERE ? < stream_id AND stream_id <= ?"
                 " ORDER BY stream_id ASC LIMIT ?"
             )
-            txn.execute(sql, (last_room_id, current_id, limit))
-            room_results = txn.fetchall()
-            return global_results, room_results
+            txn.execute(sql, (last_id, current_id, limit))
+            return txn.fetchall()
 
-        return self.db.runInteraction(
-            "get_all_updated_account_data_txn", get_updated_account_data_txn
+        return await self.db.runInteraction(
+            "get_updated_room_account_data", get_updated_room_account_data_txn
         )
 
     def get_updated_account_data_for_user(self, user_id, stream_id):
diff --git a/synapse/storage/data_stores/main/appservice.py b/synapse/storage/data_stores/main/appservice.py
index efbc06c79694..7a1fe8cdd249 100644
--- a/synapse/storage/data_stores/main/appservice.py
+++ b/synapse/storage/data_stores/main/appservice.py
@@ -30,12 +30,12 @@
 
 
 def _make_exclusive_regex(services_cache):
-    # We precompie a regex constructed from all the regexes that the AS's
+    # We precompile a regex constructed from all the regexes that the AS's
     # have registered for exclusive users.
     exclusive_user_regexes = [
         regex.pattern
         for service in services_cache
-        for regex in service.get_exlusive_user_regexes()
+        for regex in service.get_exclusive_user_regexes()
     ]
     if exclusive_user_regexes:
         exclusive_user_regex = "|".join("(" + r + ")" for r in exclusive_user_regexes)
diff --git a/synapse/storage/data_stores/main/cache.py b/synapse/storage/data_stores/main/cache.py
index 4dc5da3fe8b6..eac5a4e55bd1 100644
--- a/synapse/storage/data_stores/main/cache.py
+++ b/synapse/storage/data_stores/main/cache.py
@@ -18,9 +18,13 @@
 import logging
 from typing import Any, Iterable, Optional, Tuple
 
-from twisted.internet import defer
-
+from synapse.api.constants import EventTypes
+from synapse.replication.tcp.streams.events import (
+    EventsStreamCurrentStateRow,
+    EventsStreamEventRow,
+)
 from synapse.storage._base import SQLBaseStore
+from synapse.storage.database import Database
 from synapse.storage.engines import PostgresEngine
 from synapse.util.iterutils import batch_iter
 
@@ -33,28 +37,132 @@
 
 
 class CacheInvalidationWorkerStore(SQLBaseStore):
-    def get_all_updated_caches(self, last_id, current_id, limit):
+    def __init__(self, database: Database, db_conn, hs):
+        super().__init__(database, db_conn, hs)
+
+        self._instance_name = hs.get_instance_name()
+
+    async def get_all_updated_caches(
+        self, instance_name: str, last_id: int, current_id: int, limit: int
+    ):
+        """Fetches cache invalidation rows between the two given IDs written
+        by the given instance. Returns at most `limit` rows.
+        """
+
         if last_id == current_id:
-            return defer.succeed([])
+            return []
 
         def get_all_updated_caches_txn(txn):
             # We purposefully don't bound by the current token, as we want to
             # send across cache invalidations as quickly as possible. Cache
             # invalidations are idempotent, so duplicates are fine.
-            sql = (
-                "SELECT stream_id, cache_func, keys, invalidation_ts"
-                " FROM cache_invalidation_stream"
-                " WHERE stream_id > ? ORDER BY stream_id ASC LIMIT ?"
-            )
-            txn.execute(sql, (last_id, limit))
+            sql = """
+                SELECT stream_id, cache_func, keys, invalidation_ts
+                FROM cache_invalidation_stream_by_instance
+                WHERE stream_id > ? AND instance_name = ?
+                ORDER BY stream_id ASC
+                LIMIT ?
+            """
+            txn.execute(sql, (last_id, instance_name, limit))
             return txn.fetchall()
 
-        return self.db.runInteraction(
+        return await self.db.runInteraction(
             "get_all_updated_caches", get_all_updated_caches_txn
         )
 
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
+        if stream_name == "events":
+            for row in rows:
+                self._process_event_stream_row(token, row)
+        elif stream_name == "backfill":
+            for row in rows:
+                self._invalidate_caches_for_event(
+                    -token,
+                    row.event_id,
+                    row.room_id,
+                    row.type,
+                    row.state_key,
+                    row.redacts,
+                    row.relates_to,
+                    backfilled=True,
+                )
+        elif stream_name == "caches":
+            if self._cache_id_gen:
+                self._cache_id_gen.advance(instance_name, token)
+
+            for row in rows:
+                if row.cache_func == CURRENT_STATE_CACHE_NAME:
+                    if row.keys is None:
+                        raise Exception(
+                            "Can't send an 'invalidate all' for current state cache"
+                        )
+
+                    room_id = row.keys[0]
+                    members_changed = set(row.keys[1:])
+                    self._invalidate_state_caches(room_id, members_changed)
+                else:
+                    self._attempt_to_invalidate_cache(row.cache_func, row.keys)
+
+        super().process_replication_rows(stream_name, instance_name, token, rows)
+
+    def _process_event_stream_row(self, token, row):
+        data = row.data
+
+        if row.type == EventsStreamEventRow.TypeId:
+            self._invalidate_caches_for_event(
+                token,
+                data.event_id,
+                data.room_id,
+                data.type,
+                data.state_key,
+                data.redacts,
+                data.relates_to,
+                backfilled=False,
+            )
+        elif row.type == EventsStreamCurrentStateRow.TypeId:
+            self._curr_state_delta_stream_cache.entity_has_changed(
+                row.data.room_id, token
+            )
+
+            if data.type == EventTypes.Member:
+                self.get_rooms_for_user_with_stream_ordering.invalidate(
+                    (data.state_key,)
+                )
+        else:
+            raise Exception("Unknown events stream row type %s" % (row.type,))
+
+    def _invalidate_caches_for_event(
+        self,
+        stream_ordering,
+        event_id,
+        room_id,
+        etype,
+        state_key,
+        redacts,
+        relates_to,
+        backfilled,
+    ):
+        self._invalidate_get_event_cache(event_id)
+
+        self.get_latest_event_ids_in_room.invalidate((room_id,))
+
+        self.get_unread_event_push_actions_by_room_for_user.invalidate_many((room_id,))
+
+        if not backfilled:
+            self._events_stream_cache.entity_has_changed(room_id, stream_ordering)
+
+        if redacts:
+            self._invalidate_get_event_cache(redacts)
+
+        if etype == EventTypes.Member:
+            self._membership_stream_cache.entity_has_changed(state_key, stream_ordering)
+            self.get_invited_rooms_for_local_user.invalidate((state_key,))
+
+        if relates_to:
+            self.get_relations_for_event.invalidate_many((relates_to,))
+            self.get_aggregation_groups_for_event.invalidate_many((relates_to,))
+            self.get_applicable_edit.invalidate((relates_to,))
 
-class CacheInvalidationStore(CacheInvalidationWorkerStore):
     async def invalidate_cache_and_stream(self, cache_name: str, keys: Tuple[Any, ...]):
         """Invalidates the cache and adds it to the cache stream so slaves
         will know to invalidate their caches.
@@ -68,7 +176,7 @@ async def invalidate_cache_and_stream(self, cache_name: str, keys: Tuple[Any, ..
             return
 
         cache_func.invalidate(keys)
-        await self.runInteraction(
+        await self.db.runInteraction(
             "invalidate_cache_and_stream",
             self._send_invalidation_to_replication,
             cache_func.__name__,
@@ -147,10 +255,7 @@ def _send_invalidation_to_replication(
             # the transaction. However, we want to only get an ID when we want
             # to use it, here, so we need to call __enter__ manually, and have
             # __exit__ called after the transaction finishes.
-            ctx = self._cache_id_gen.get_next()
-            stream_id = ctx.__enter__()
-            txn.call_on_exception(ctx.__exit__, None, None, None)
-            txn.call_after(ctx.__exit__, None, None, None)
+            stream_id = self._cache_id_gen.get_next_txn(txn)
             txn.call_after(self.hs.get_notifier().on_new_replication_data)
 
             if keys is not None:
@@ -158,17 +263,18 @@ def _send_invalidation_to_replication(
 
             self.db.simple_insert_txn(
                 txn,
-                table="cache_invalidation_stream",
+                table="cache_invalidation_stream_by_instance",
                 values={
                     "stream_id": stream_id,
+                    "instance_name": self._instance_name,
                     "cache_func": cache_name,
                     "keys": keys,
                     "invalidation_ts": self.clock.time_msec(),
                 },
             )
 
-    def get_cache_stream_token(self):
+    def get_cache_stream_token(self, instance_name):
         if self._cache_id_gen:
-            return self._cache_id_gen.get_current_token()
+            return self._cache_id_gen.get_current_token(instance_name)
         else:
             return 0
diff --git a/synapse/storage/data_stores/main/censor_events.py b/synapse/storage/data_stores/main/censor_events.py
new file mode 100644
index 000000000000..2d4826172457
--- /dev/null
+++ b/synapse/storage/data_stores/main/censor_events.py
@@ -0,0 +1,208 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from typing import TYPE_CHECKING
+
+from twisted.internet import defer
+
+from synapse.events.utils import prune_event_dict
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.cache import CacheInvalidationWorkerStore
+from synapse.storage.data_stores.main.events import encode_json
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
+from synapse.storage.database import Database
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+
+logger = logging.getLogger(__name__)
+
+
+class CensorEventsStore(EventsWorkerStore, CacheInvalidationWorkerStore, SQLBaseStore):
+    def __init__(self, database: Database, db_conn, hs: "HomeServer"):
+        super().__init__(database, db_conn, hs)
+
+        def _censor_redactions():
+            return run_as_background_process(
+                "_censor_redactions", self._censor_redactions
+            )
+
+        if self.hs.config.redaction_retention_period is not None:
+            hs.get_clock().looping_call(_censor_redactions, 5 * 60 * 1000)
+
+    async def _censor_redactions(self):
+        """Censors all redactions older than the configured period that haven't
+        been censored yet.
+
+        By censor we mean update the event_json table with the redacted event.
+        """
+
+        if self.hs.config.redaction_retention_period is None:
+            return
+
+        if not (
+            await self.db.updates.has_completed_background_update(
+                "redactions_have_censored_ts_idx"
+            )
+        ):
+            # We don't want to run this until the appropriate index has been
+            # created.
+            return
+
+        before_ts = self._clock.time_msec() - self.hs.config.redaction_retention_period
+
+        # We fetch all redactions that:
+        #   1. point to an event we have,
+        #   2. has a received_ts from before the cut off, and
+        #   3. we haven't yet censored.
+        #
+        # This is limited to 100 events to ensure that we don't try and do too
+        # much at once. We'll get called again so this should eventually catch
+        # up.
+        sql = """
+            SELECT redactions.event_id, redacts FROM redactions
+            LEFT JOIN events AS original_event ON (
+                redacts = original_event.event_id
+            )
+            WHERE NOT have_censored
+            AND redactions.received_ts <= ?
+            ORDER BY redactions.received_ts ASC
+            LIMIT ?
+        """
+
+        rows = await self.db.execute(
+            "_censor_redactions_fetch", None, sql, before_ts, 100
+        )
+
+        updates = []
+
+        for redaction_id, event_id in rows:
+            redaction_event = await self.get_event(redaction_id, allow_none=True)
+            original_event = await self.get_event(
+                event_id, allow_rejected=True, allow_none=True
+            )
+
+            # The SQL above ensures that we have both the redaction and
+            # original event, so if the `get_event` calls return None it
+            # means that the redaction wasn't allowed. Either way we know that
+            # the result won't change so we mark the fact that we've checked.
+            if (
+                redaction_event
+                and original_event
+                and original_event.internal_metadata.is_redacted()
+            ):
+                # Redaction was allowed
+                pruned_json = encode_json(
+                    prune_event_dict(
+                        original_event.room_version, original_event.get_dict()
+                    )
+                )
+            else:
+                # Redaction wasn't allowed
+                pruned_json = None
+
+            updates.append((redaction_id, event_id, pruned_json))
+
+        def _update_censor_txn(txn):
+            for redaction_id, event_id, pruned_json in updates:
+                if pruned_json:
+                    self._censor_event_txn(txn, event_id, pruned_json)
+
+                self.db.simple_update_one_txn(
+                    txn,
+                    table="redactions",
+                    keyvalues={"event_id": redaction_id},
+                    updatevalues={"have_censored": True},
+                )
+
+        await self.db.runInteraction("_update_censor_txn", _update_censor_txn)
+
+    def _censor_event_txn(self, txn, event_id, pruned_json):
+        """Censor an event by replacing its JSON in the event_json table with the
+        provided pruned JSON.
+
+        Args:
+            txn (LoggingTransaction): The database transaction.
+            event_id (str): The ID of the event to censor.
+            pruned_json (str): The pruned JSON
+        """
+        self.db.simple_update_one_txn(
+            txn,
+            table="event_json",
+            keyvalues={"event_id": event_id},
+            updatevalues={"json": pruned_json},
+        )
+
+    @defer.inlineCallbacks
+    def expire_event(self, event_id):
+        """Retrieve and expire an event that has expired, and delete its associated
+        expiry timestamp. If the event can't be retrieved, delete its associated
+        timestamp so we don't try to expire it again in the future.
+
+        Args:
+             event_id (str): The ID of the event to delete.
+        """
+        # Try to retrieve the event's content from the database or the event cache.
+        event = yield self.get_event(event_id)
+
+        def delete_expired_event_txn(txn):
+            # Delete the expiry timestamp associated with this event from the database.
+            self._delete_event_expiry_txn(txn, event_id)
+
+            if not event:
+                # If we can't find the event, log a warning and delete the expiry date
+                # from the database so that we don't try to expire it again in the
+                # future.
+                logger.warning(
+                    "Can't expire event %s because we don't have it.", event_id
+                )
+                return
+
+            # Prune the event's dict then convert it to JSON.
+            pruned_json = encode_json(
+                prune_event_dict(event.room_version, event.get_dict())
+            )
+
+            # Update the event_json table to replace the event's JSON with the pruned
+            # JSON.
+            self._censor_event_txn(txn, event.event_id, pruned_json)
+
+            # We need to invalidate the event cache entry for this event because we
+            # changed its content in the database. We can't call
+            # self._invalidate_cache_and_stream because self.get_event_cache isn't of the
+            # right type.
+            txn.call_after(self._get_event_cache.invalidate, (event.event_id,))
+            # Send that invalidation to replication so that other workers also invalidate
+            # the event cache.
+            self._send_invalidation_to_replication(
+                txn, "_get_event_cache", (event.event_id,)
+            )
+
+        yield self.db.runInteraction("delete_expired_event", delete_expired_event_txn)
+
+    def _delete_event_expiry_txn(self, txn, event_id):
+        """Delete the expiry timestamp associated with an event ID without deleting the
+        actual event.
+
+        Args:
+            txn (LoggingTransaction): The transaction to use to perform the deletion.
+            event_id (str): The event ID to delete the associated expiry timestamp of.
+        """
+        return self.db.simple_delete_txn(
+            txn=txn, table="event_expiry", keyvalues={"event_id": event_id}
+        )
diff --git a/synapse/storage/data_stores/main/client_ips.py b/synapse/storage/data_stores/main/client_ips.py
index b596200a18a6..ea06f74535fb 100644
--- a/synapse/storage/data_stores/main/client_ips.py
+++ b/synapse/storage/data_stores/main/client_ips.py
@@ -22,7 +22,6 @@
 from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import Database, make_tuple_comparison_clause
-from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.caches.descriptors import Cache
 
 logger = logging.getLogger(__name__)
@@ -361,7 +360,7 @@ class ClientIpStore(ClientIpBackgroundUpdateStore):
     def __init__(self, database: Database, db_conn, hs):
 
         self.client_ip_last_seen = Cache(
-            name="client_ip_last_seen", keylen=4, max_entries=50000 * CACHE_SIZE_FACTOR
+            name="client_ip_last_seen", keylen=4, max_entries=50000
         )
 
         super(ClientIpStore, self).__init__(database, db_conn, hs)
diff --git a/synapse/storage/data_stores/main/event_federation.py b/synapse/storage/data_stores/main/event_federation.py
index b99439cc3784..24ce8c433059 100644
--- a/synapse/storage/data_stores/main/event_federation.py
+++ b/synapse/storage/data_stores/main/event_federation.py
@@ -640,89 +640,6 @@ def __init__(self, database: Database, db_conn, hs):
             self._delete_old_forward_extrem_cache, 60 * 60 * 1000
         )
 
-    def _update_min_depth_for_room_txn(self, txn, room_id, depth):
-        min_depth = self._get_min_depth_interaction(txn, room_id)
-
-        if min_depth is not None and depth >= min_depth:
-            return
-
-        self.db.simple_upsert_txn(
-            txn,
-            table="room_depth",
-            keyvalues={"room_id": room_id},
-            values={"min_depth": depth},
-        )
-
-    def _handle_mult_prev_events(self, txn, events):
-        """
-        For the given event, update the event edges table and forward and
-        backward extremities tables.
-        """
-        self.db.simple_insert_many_txn(
-            txn,
-            table="event_edges",
-            values=[
-                {
-                    "event_id": ev.event_id,
-                    "prev_event_id": e_id,
-                    "room_id": ev.room_id,
-                    "is_state": False,
-                }
-                for ev in events
-                for e_id in ev.prev_event_ids()
-            ],
-        )
-
-        self._update_backward_extremeties(txn, events)
-
-    def _update_backward_extremeties(self, txn, events):
-        """Updates the event_backward_extremities tables based on the new/updated
-        events being persisted.
-
-        This is called for new events *and* for events that were outliers, but
-        are now being persisted as non-outliers.
-
-        Forward extremities are handled when we first start persisting the events.
-        """
-        events_by_room = {}
-        for ev in events:
-            events_by_room.setdefault(ev.room_id, []).append(ev)
-
-        query = (
-            "INSERT INTO event_backward_extremities (event_id, room_id)"
-            " SELECT ?, ? WHERE NOT EXISTS ("
-            " SELECT 1 FROM event_backward_extremities"
-            " WHERE event_id = ? AND room_id = ?"
-            " )"
-            " AND NOT EXISTS ("
-            " SELECT 1 FROM events WHERE event_id = ? AND room_id = ? "
-            " AND outlier = ?"
-            " )"
-        )
-
-        txn.executemany(
-            query,
-            [
-                (e_id, ev.room_id, e_id, ev.room_id, e_id, ev.room_id, False)
-                for ev in events
-                for e_id in ev.prev_event_ids()
-                if not ev.internal_metadata.is_outlier()
-            ],
-        )
-
-        query = (
-            "DELETE FROM event_backward_extremities"
-            " WHERE event_id = ? AND room_id = ?"
-        )
-        txn.executemany(
-            query,
-            [
-                (ev.event_id, ev.room_id)
-                for ev in events
-                if not ev.internal_metadata.is_outlier()
-            ],
-        )
-
     def _delete_old_forward_extrem_cache(self):
         def _delete_old_forward_extrem_cache_txn(txn):
             # Delete entries older than a month, while making sure we don't delete
diff --git a/synapse/storage/data_stores/main/event_push_actions.py b/synapse/storage/data_stores/main/event_push_actions.py
index 8eed59092991..0321274de2c5 100644
--- a/synapse/storage/data_stores/main/event_push_actions.py
+++ b/synapse/storage/data_stores/main/event_push_actions.py
@@ -652,69 +652,6 @@ def __init__(self, database: Database, db_conn, hs):
             self._start_rotate_notifs, 30 * 60 * 1000
         )
 
-    def _set_push_actions_for_event_and_users_txn(
-        self, txn, events_and_contexts, all_events_and_contexts
-    ):
-        """Handles moving push actions from staging table to main
-        event_push_actions table for all events in `events_and_contexts`.
-
-        Also ensures that all events in `all_events_and_contexts` are removed
-        from the push action staging area.
-
-        Args:
-            events_and_contexts (list[(EventBase, EventContext)]): events
-                we are persisting
-            all_events_and_contexts (list[(EventBase, EventContext)]): all
-                events that we were going to persist. This includes events
-                we've already persisted, etc, that wouldn't appear in
-                events_and_context.
-        """
-
-        sql = """
-            INSERT INTO event_push_actions (
-                room_id, event_id, user_id, actions, stream_ordering,
-                topological_ordering, notif, highlight
-            )
-            SELECT ?, event_id, user_id, actions, ?, ?, notif, highlight
-            FROM event_push_actions_staging
-            WHERE event_id = ?
-        """
-
-        if events_and_contexts:
-            txn.executemany(
-                sql,
-                (
-                    (
-                        event.room_id,
-                        event.internal_metadata.stream_ordering,
-                        event.depth,
-                        event.event_id,
-                    )
-                    for event, _ in events_and_contexts
-                ),
-            )
-
-        for event, _ in events_and_contexts:
-            user_ids = self.db.simple_select_onecol_txn(
-                txn,
-                table="event_push_actions_staging",
-                keyvalues={"event_id": event.event_id},
-                retcol="user_id",
-            )
-
-            for uid in user_ids:
-                txn.call_after(
-                    self.get_unread_event_push_actions_by_room_for_user.invalidate_many,
-                    (event.room_id, uid),
-                )
-
-        # Now we delete the staging area for *all* events that were being
-        # persisted.
-        txn.executemany(
-            "DELETE FROM event_push_actions_staging WHERE event_id = ?",
-            ((event.event_id,) for event, _ in all_events_and_contexts),
-        )
-
     @defer.inlineCallbacks
     def get_push_actions_for_user(
         self, user_id, before=None, limit=50, only_highlight=False
@@ -763,17 +700,6 @@ def f(txn):
         )
         return result[0] or 0
 
-    def _remove_push_actions_for_event_id_txn(self, txn, room_id, event_id):
-        # Sad that we have to blow away the cache for the whole room here
-        txn.call_after(
-            self.get_unread_event_push_actions_by_room_for_user.invalidate_many,
-            (room_id,),
-        )
-        txn.execute(
-            "DELETE FROM event_push_actions WHERE room_id = ? AND event_id = ?",
-            (room_id, event_id),
-        )
-
     def _remove_old_push_actions_before_txn(
         self, txn, room_id, user_id, stream_ordering
     ):
diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py
index e71c23541d09..a97f8b39344e 100644
--- a/synapse/storage/data_stores/main/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -17,39 +17,44 @@
 
 import itertools
 import logging
-from collections import Counter as c_counter, OrderedDict, namedtuple
+from collections import OrderedDict, namedtuple
 from functools import wraps
-from typing import Dict, List, Tuple
+from typing import TYPE_CHECKING, Dict, Iterable, List, Tuple
 
-from six import iteritems, text_type
+from six import integer_types, iteritems, text_type
 from six.moves import range
 
+import attr
 from canonicaljson import json
 from prometheus_client import Counter
 
 from twisted.internet import defer
 
 import synapse.metrics
-from synapse.api.constants import EventContentFields, EventTypes
-from synapse.api.errors import SynapseError
+from synapse.api.constants import (
+    EventContentFields,
+    EventTypes,
+    Membership,
+    RelationTypes,
+)
 from synapse.api.room_versions import RoomVersions
+from synapse.crypto.event_signing import compute_event_reference_hash
 from synapse.events import EventBase  # noqa: F401
 from synapse.events.snapshot import EventContext  # noqa: F401
-from synapse.events.utils import prune_event_dict
 from synapse.logging.utils import log_function
-from synapse.metrics import BucketCollector
-from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage._base import make_in_list_sql_clause
-from synapse.storage.data_stores.main.event_federation import EventFederationStore
-from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
-from synapse.storage.data_stores.main.state import StateGroupWorkerStore
+from synapse.storage.data_stores.main.search import SearchEntry
 from synapse.storage.database import Database, LoggingTransaction
-from synapse.storage.persist_events import DeltaState
-from synapse.types import RoomStreamToken, StateMap, get_domain_from_id
-from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
+from synapse.storage.util.id_generators import StreamIdGenerator
+from synapse.types import StateMap, get_domain_from_id
 from synapse.util.frozenutils import frozendict_json_encoder
 from synapse.util.iterutils import batch_iter
 
+if TYPE_CHECKING:
+    from synapse.storage.data_stores.main import DataStore
+    from synapse.server import HomeServer
+
+
 logger = logging.getLogger(__name__)
 
 persist_event_counter = Counter("synapse_storage_events_persisted_events", "")
@@ -94,58 +99,49 @@ def f(self, *args, **kwargs):
     return f
 
 
-# inherits from EventFederationStore so that we can call _update_backward_extremities
-# and _handle_mult_prev_events (though arguably those could both be moved in here)
-class EventsStore(
-    StateGroupWorkerStore, EventFederationStore, EventsWorkerStore,
-):
-    def __init__(self, database: Database, db_conn, hs):
-        super(EventsStore, self).__init__(database, db_conn, hs)
+@attr.s(slots=True)
+class DeltaState:
+    """Deltas to use to update the `current_state_events` table.
 
-        # Collect metrics on the number of forward extremities that exist.
-        # Counter of number of extremities to count
-        self._current_forward_extremities_amount = c_counter()
+    Attributes:
+        to_delete: List of type/state_keys to delete from current state
+        to_insert: Map of state to upsert into current state
+        no_longer_in_room: The server is not longer in the room, so the room
+            should e.g. be removed from `current_state_events` table.
+    """
 
-        BucketCollector(
-            "synapse_forward_extremities",
-            lambda: self._current_forward_extremities_amount,
-            buckets=[1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"],
-        )
+    to_delete = attr.ib(type=List[Tuple[str, str]])
+    to_insert = attr.ib(type=StateMap[str])
+    no_longer_in_room = attr.ib(type=bool, default=False)
 
-        # Read the extrems every 60 minutes
-        def read_forward_extremities():
-            # run as a background process to make sure that the database transactions
-            # have a logcontext to report to
-            return run_as_background_process(
-                "read_forward_extremities", self._read_forward_extremities
-            )
 
-        hs.get_clock().looping_call(read_forward_extremities, 60 * 60 * 1000)
+class PersistEventsStore:
+    """Contains all the functions for writing events to the database.
 
-        def _censor_redactions():
-            return run_as_background_process(
-                "_censor_redactions", self._censor_redactions
-            )
+    Should only be instantiated on one process (when using a worker mode setup).
+
+    Note: This is not part of the `DataStore` mixin.
+    """
 
-        if self.hs.config.redaction_retention_period is not None:
-            hs.get_clock().looping_call(_censor_redactions, 5 * 60 * 1000)
+    def __init__(self, hs: "HomeServer", db: Database, main_data_store: "DataStore"):
+        self.hs = hs
+        self.db = db
+        self.store = main_data_store
+        self.database_engine = db.engine
+        self._clock = hs.get_clock()
 
         self._ephemeral_messages_enabled = hs.config.enable_ephemeral_messages
         self.is_mine_id = hs.is_mine_id
 
-    @defer.inlineCallbacks
-    def _read_forward_extremities(self):
-        def fetch(txn):
-            txn.execute(
-                """
-                select count(*) c from event_forward_extremities
-                group by room_id
-                """
-            )
-            return txn.fetchall()
+        # Ideally we'd move these ID gens here, unfortunately some other ID
+        # generators are chained off them so doing so is a bit of a PITA.
+        self._backfill_id_gen = self.store._backfill_id_gen  # type: StreamIdGenerator
+        self._stream_id_gen = self.store._stream_id_gen  # type: StreamIdGenerator
 
-        res = yield self.db.runInteraction("read_forward_extremities", fetch)
-        self._current_forward_extremities_amount = c_counter([x[0] for x in res])
+        # This should only exist on master for now
+        assert (
+            hs.config.worker.worker_app is None
+        ), "Can only instantiate PersistEventsStore on master"
 
     @_retry_on_integrity_error
     @defer.inlineCallbacks
@@ -237,10 +233,10 @@ def _persist_events_and_state_updates(
                 event_counter.labels(event.type, origin_type, origin_entity).inc()
 
             for room_id, new_state in iteritems(current_state_for_room):
-                self.get_current_state_ids.prefill((room_id,), new_state)
+                self.store.get_current_state_ids.prefill((room_id,), new_state)
 
             for room_id, latest_event_ids in iteritems(new_forward_extremeties):
-                self.get_latest_event_ids_in_room.prefill(
+                self.store.get_latest_event_ids_in_room.prefill(
                     (room_id,), list(latest_event_ids)
                 )
 
@@ -586,7 +582,7 @@ def _update_current_state_txn(
                 )
 
             txn.call_after(
-                self._curr_state_delta_stream_cache.entity_has_changed,
+                self.store._curr_state_delta_stream_cache.entity_has_changed,
                 room_id,
                 stream_id,
             )
@@ -606,10 +602,13 @@ def _update_current_state_txn(
 
             for member in members_changed:
                 txn.call_after(
-                    self.get_rooms_for_user_with_stream_ordering.invalidate, (member,)
+                    self.store.get_rooms_for_user_with_stream_ordering.invalidate,
+                    (member,),
                 )
 
-            self._invalidate_state_caches_and_stream(txn, room_id, members_changed)
+            self.store._invalidate_state_caches_and_stream(
+                txn, room_id, members_changed
+            )
 
     def _upsert_room_version_txn(self, txn: LoggingTransaction, room_id: str):
         """Update the room version in the database based off current state
@@ -647,7 +646,9 @@ def _update_forward_extremities_txn(
             self.db.simple_delete_txn(
                 txn, table="event_forward_extremities", keyvalues={"room_id": room_id}
             )
-            txn.call_after(self.get_latest_event_ids_in_room.invalidate, (room_id,))
+            txn.call_after(
+                self.store.get_latest_event_ids_in_room.invalidate, (room_id,)
+            )
 
         self.db.simple_insert_many_txn(
             txn,
@@ -713,10 +714,10 @@ def _update_room_depths_txn(self, txn, events_and_contexts, backfilled):
         depth_updates = {}
         for event, context in events_and_contexts:
             # Remove the any existing cache entries for the event_ids
-            txn.call_after(self._invalidate_get_event_cache, event.event_id)
+            txn.call_after(self.store._invalidate_get_event_cache, event.event_id)
             if not backfilled:
                 txn.call_after(
-                    self._events_stream_cache.entity_has_changed,
+                    self.store._events_stream_cache.entity_has_changed,
                     event.room_id,
                     event.internal_metadata.stream_ordering,
                 )
@@ -1088,13 +1089,15 @@ def _add_to_cache(self, txn, events_and_contexts):
 
         def prefill():
             for cache_entry in to_prefill:
-                self._get_event_cache.prefill((cache_entry[0].event_id,), cache_entry)
+                self.store._get_event_cache.prefill(
+                    (cache_entry[0].event_id,), cache_entry
+                )
 
         txn.call_after(prefill)
 
     def _store_redaction(self, txn, event):
         # invalidate the cache for the redacted event
-        txn.call_after(self._invalidate_get_event_cache, event.redacts)
+        txn.call_after(self.store._invalidate_get_event_cache, event.redacts)
 
         self.db.simple_insert_txn(
             txn,
@@ -1106,783 +1109,484 @@ def _store_redaction(self, txn, event):
             },
         )
 
-    async def _censor_redactions(self):
-        """Censors all redactions older than the configured period that haven't
-        been censored yet.
+    def insert_labels_for_event_txn(
+        self, txn, event_id, labels, room_id, topological_ordering
+    ):
+        """Store the mapping between an event's ID and its labels, with one row per
+        (event_id, label) tuple.
 
-        By censor we mean update the event_json table with the redacted event.
+        Args:
+            txn (LoggingTransaction): The transaction to execute.
+            event_id (str): The event's ID.
+            labels (list[str]): A list of text labels.
+            room_id (str): The ID of the room the event was sent to.
+            topological_ordering (int): The position of the event in the room's topology.
         """
+        return self.db.simple_insert_many_txn(
+            txn=txn,
+            table="event_labels",
+            values=[
+                {
+                    "event_id": event_id,
+                    "label": label,
+                    "room_id": room_id,
+                    "topological_ordering": topological_ordering,
+                }
+                for label in labels
+            ],
+        )
 
-        if self.hs.config.redaction_retention_period is None:
-            return
-
-        if not (
-            await self.db.updates.has_completed_background_update(
-                "redactions_have_censored_ts_idx"
-            )
-        ):
-            # We don't want to run this until the appropriate index has been
-            # created.
-            return
-
-        before_ts = self._clock.time_msec() - self.hs.config.redaction_retention_period
+    def _insert_event_expiry_txn(self, txn, event_id, expiry_ts):
+        """Save the expiry timestamp associated with a given event ID.
 
-        # We fetch all redactions that:
-        #   1. point to an event we have,
-        #   2. has a received_ts from before the cut off, and
-        #   3. we haven't yet censored.
-        #
-        # This is limited to 100 events to ensure that we don't try and do too
-        # much at once. We'll get called again so this should eventually catch
-        # up.
-        sql = """
-            SELECT redactions.event_id, redacts FROM redactions
-            LEFT JOIN events AS original_event ON (
-                redacts = original_event.event_id
-            )
-            WHERE NOT have_censored
-            AND redactions.received_ts <= ?
-            ORDER BY redactions.received_ts ASC
-            LIMIT ?
+        Args:
+            txn (LoggingTransaction): The database transaction to use.
+            event_id (str): The event ID the expiry timestamp is associated with.
+            expiry_ts (int): The timestamp at which to expire (delete) the event.
         """
-
-        rows = await self.db.execute(
-            "_censor_redactions_fetch", None, sql, before_ts, 100
+        return self.db.simple_insert_txn(
+            txn=txn,
+            table="event_expiry",
+            values={"event_id": event_id, "expiry_ts": expiry_ts},
         )
 
-        updates = []
+    def _store_event_reference_hashes_txn(self, txn, events):
+        """Store a hash for a PDU
+        Args:
+            txn (cursor):
+            events (list): list of Events.
+        """
 
-        for redaction_id, event_id in rows:
-            redaction_event = await self.get_event(redaction_id, allow_none=True)
-            original_event = await self.get_event(
-                event_id, allow_rejected=True, allow_none=True
+        vals = []
+        for event in events:
+            ref_alg, ref_hash_bytes = compute_event_reference_hash(event)
+            vals.append(
+                {
+                    "event_id": event.event_id,
+                    "algorithm": ref_alg,
+                    "hash": memoryview(ref_hash_bytes),
+                }
             )
 
-            # The SQL above ensures that we have both the redaction and
-            # original event, so if the `get_event` calls return None it
-            # means that the redaction wasn't allowed. Either way we know that
-            # the result won't change so we mark the fact that we've checked.
-            if (
-                redaction_event
-                and original_event
-                and original_event.internal_metadata.is_redacted()
-            ):
-                # Redaction was allowed
-                pruned_json = encode_json(
-                    prune_event_dict(
-                        original_event.room_version, original_event.get_dict()
-                    )
-                )
-            else:
-                # Redaction wasn't allowed
-                pruned_json = None
-
-            updates.append((redaction_id, event_id, pruned_json))
-
-        def _update_censor_txn(txn):
-            for redaction_id, event_id, pruned_json in updates:
-                if pruned_json:
-                    self._censor_event_txn(txn, event_id, pruned_json)
-
-                self.db.simple_update_one_txn(
-                    txn,
-                    table="redactions",
-                    keyvalues={"event_id": redaction_id},
-                    updatevalues={"have_censored": True},
-                )
-
-        await self.db.runInteraction("_update_censor_txn", _update_censor_txn)
+        self.db.simple_insert_many_txn(txn, table="event_reference_hashes", values=vals)
 
-    def _censor_event_txn(self, txn, event_id, pruned_json):
-        """Censor an event by replacing its JSON in the event_json table with the
-        provided pruned JSON.
-
-        Args:
-            txn (LoggingTransaction): The database transaction.
-            event_id (str): The ID of the event to censor.
-            pruned_json (str): The pruned JSON
+    def _store_room_members_txn(self, txn, events, backfilled):
+        """Store a room member in the database.
         """
-        self.db.simple_update_one_txn(
+        self.db.simple_insert_many_txn(
             txn,
-            table="event_json",
-            keyvalues={"event_id": event_id},
-            updatevalues={"json": pruned_json},
+            table="room_memberships",
+            values=[
+                {
+                    "event_id": event.event_id,
+                    "user_id": event.state_key,
+                    "sender": event.user_id,
+                    "room_id": event.room_id,
+                    "membership": event.membership,
+                    "display_name": event.content.get("displayname", None),
+                    "avatar_url": event.content.get("avatar_url", None),
+                }
+                for event in events
+            ],
         )
 
-    @defer.inlineCallbacks
-    def count_daily_messages(self):
-        """
-        Returns an estimate of the number of messages sent in the last day.
-
-        If it has been significantly less or more than one day since the last
-        call to this function, it will return None.
-        """
-
-        def _count_messages(txn):
-            sql = """
-                SELECT COALESCE(COUNT(*), 0) FROM events
-                WHERE type = 'm.room.message'
-                AND stream_ordering > ?
-            """
-            txn.execute(sql, (self.stream_ordering_day_ago,))
-            (count,) = txn.fetchone()
-            return count
-
-        ret = yield self.db.runInteraction("count_messages", _count_messages)
-        return ret
-
-    @defer.inlineCallbacks
-    def count_daily_sent_messages(self):
-        def _count_messages(txn):
-            # This is good enough as if you have silly characters in your own
-            # hostname then thats your own fault.
-            like_clause = "%:" + self.hs.hostname
-
-            sql = """
-                SELECT COALESCE(COUNT(*), 0) FROM events
-                WHERE type = 'm.room.message'
-                    AND sender LIKE ?
-                AND stream_ordering > ?
-            """
-
-            txn.execute(sql, (like_clause, self.stream_ordering_day_ago))
-            (count,) = txn.fetchone()
-            return count
-
-        ret = yield self.db.runInteraction("count_daily_sent_messages", _count_messages)
-        return ret
-
-    @defer.inlineCallbacks
-    def count_daily_active_rooms(self):
-        def _count(txn):
-            sql = """
-                SELECT COALESCE(COUNT(DISTINCT room_id), 0) FROM events
-                WHERE type = 'm.room.message'
-                AND stream_ordering > ?
-            """
-            txn.execute(sql, (self.stream_ordering_day_ago,))
-            (count,) = txn.fetchone()
-            return count
-
-        ret = yield self.db.runInteraction("count_daily_active_rooms", _count)
-        return ret
-
-    @cached(num_args=5, max_entries=10)
-    def get_all_new_events(
-        self,
-        last_backfill_id,
-        last_forward_id,
-        current_backfill_id,
-        current_forward_id,
-        limit,
-    ):
-        """Get all the new events that have arrived at the server either as
-        new events or as backfilled events"""
-        have_backfill_events = last_backfill_id != current_backfill_id
-        have_forward_events = last_forward_id != current_forward_id
-
-        if not have_backfill_events and not have_forward_events:
-            return defer.succeed(AllNewEventsResult([], [], [], [], []))
-
-        def get_all_new_events_txn(txn):
-            sql = (
-                "SELECT e.stream_ordering, e.event_id, e.room_id, e.type,"
-                " state_key, redacts"
-                " FROM events AS e"
-                " LEFT JOIN redactions USING (event_id)"
-                " LEFT JOIN state_events USING (event_id)"
-                " WHERE ? < stream_ordering AND stream_ordering <= ?"
-                " ORDER BY stream_ordering ASC"
-                " LIMIT ?"
+        for event in events:
+            txn.call_after(
+                self.store._membership_stream_cache.entity_has_changed,
+                event.state_key,
+                event.internal_metadata.stream_ordering,
             )
-            if have_forward_events:
-                txn.execute(sql, (last_forward_id, current_forward_id, limit))
-                new_forward_events = txn.fetchall()
-
-                if len(new_forward_events) == limit:
-                    upper_bound = new_forward_events[-1][0]
-                else:
-                    upper_bound = current_forward_id
-
-                sql = (
-                    "SELECT event_stream_ordering, event_id, state_group"
-                    " FROM ex_outlier_stream"
-                    " WHERE ? > event_stream_ordering"
-                    " AND event_stream_ordering >= ?"
-                    " ORDER BY event_stream_ordering DESC"
-                )
-                txn.execute(sql, (last_forward_id, upper_bound))
-                forward_ex_outliers = txn.fetchall()
-            else:
-                new_forward_events = []
-                forward_ex_outliers = []
-
-            sql = (
-                "SELECT -e.stream_ordering, e.event_id, e.room_id, e.type,"
-                " state_key, redacts"
-                " FROM events AS e"
-                " LEFT JOIN redactions USING (event_id)"
-                " LEFT JOIN state_events USING (event_id)"
-                " WHERE ? > stream_ordering AND stream_ordering >= ?"
-                " ORDER BY stream_ordering DESC"
-                " LIMIT ?"
+            txn.call_after(
+                self.store.get_invited_rooms_for_local_user.invalidate,
+                (event.state_key,),
             )
-            if have_backfill_events:
-                txn.execute(sql, (-last_backfill_id, -current_backfill_id, limit))
-                new_backfill_events = txn.fetchall()
 
-                if len(new_backfill_events) == limit:
-                    upper_bound = new_backfill_events[-1][0]
-                else:
-                    upper_bound = current_backfill_id
-
-                sql = (
-                    "SELECT -event_stream_ordering, event_id, state_group"
-                    " FROM ex_outlier_stream"
-                    " WHERE ? > event_stream_ordering"
-                    " AND event_stream_ordering >= ?"
-                    " ORDER BY event_stream_ordering DESC"
-                )
-                txn.execute(sql, (-last_backfill_id, -upper_bound))
-                backward_ex_outliers = txn.fetchall()
-            else:
-                new_backfill_events = []
-                backward_ex_outliers = []
-
-            return AllNewEventsResult(
-                new_forward_events,
-                new_backfill_events,
-                forward_ex_outliers,
-                backward_ex_outliers,
+            # We update the local_invites table only if the event is "current",
+            # i.e., its something that has just happened. If the event is an
+            # outlier it is only current if its an "out of band membership",
+            # like a remote invite or a rejection of a remote invite.
+            is_new_state = not backfilled and (
+                not event.internal_metadata.is_outlier()
+                or event.internal_metadata.is_out_of_band_membership()
             )
+            is_mine = self.is_mine_id(event.state_key)
+            if is_new_state and is_mine:
+                if event.membership == Membership.INVITE:
+                    self.db.simple_insert_txn(
+                        txn,
+                        table="local_invites",
+                        values={
+                            "event_id": event.event_id,
+                            "invitee": event.state_key,
+                            "inviter": event.sender,
+                            "room_id": event.room_id,
+                            "stream_id": event.internal_metadata.stream_ordering,
+                        },
+                    )
+                else:
+                    sql = (
+                        "UPDATE local_invites SET stream_id = ?, replaced_by = ? WHERE"
+                        " room_id = ? AND invitee = ? AND locally_rejected is NULL"
+                        " AND replaced_by is NULL"
+                    )
 
-        return self.db.runInteraction("get_all_new_events", get_all_new_events_txn)
-
-    def purge_history(self, room_id, token, delete_local_events):
-        """Deletes room history before a certain point
-
-        Args:
-            room_id (str):
+                    txn.execute(
+                        sql,
+                        (
+                            event.internal_metadata.stream_ordering,
+                            event.event_id,
+                            event.room_id,
+                            event.state_key,
+                        ),
+                    )
 
-            token (str): A topological token to delete events before
+                # We also update the `local_current_membership` table with
+                # latest invite info. This will usually get updated by the
+                # `current_state_events` handling, unless its an outlier.
+                if event.internal_metadata.is_outlier():
+                    # This should only happen for out of band memberships, so
+                    # we add a paranoia check.
+                    assert event.internal_metadata.is_out_of_band_membership()
+
+                    self.db.simple_upsert_txn(
+                        txn,
+                        table="local_current_membership",
+                        keyvalues={
+                            "room_id": event.room_id,
+                            "user_id": event.state_key,
+                        },
+                        values={
+                            "event_id": event.event_id,
+                            "membership": event.membership,
+                        },
+                    )
 
-            delete_local_events (bool):
-                if True, we will delete local events as well as remote ones
-                (instead of just marking them as outliers and deleting their
-                state groups).
+    def _handle_event_relations(self, txn, event):
+        """Handles inserting relation data during peristence of events
 
-        Returns:
-            Deferred[set[int]]: The set of state groups that are referenced by
-            deleted events.
+        Args:
+            txn
+            event (EventBase)
         """
+        relation = event.content.get("m.relates_to")
+        if not relation:
+            # No relations
+            return
 
-        return self.db.runInteraction(
-            "purge_history",
-            self._purge_history_txn,
-            room_id,
-            token,
-            delete_local_events,
-        )
+        rel_type = relation.get("rel_type")
+        if rel_type not in (
+            RelationTypes.ANNOTATION,
+            RelationTypes.REFERENCE,
+            RelationTypes.REPLACE,
+        ):
+            # Unknown relation type
+            return
 
-    def _purge_history_txn(self, txn, room_id, token_str, delete_local_events):
-        token = RoomStreamToken.parse(token_str)
-
-        # Tables that should be pruned:
-        #     event_auth
-        #     event_backward_extremities
-        #     event_edges
-        #     event_forward_extremities
-        #     event_json
-        #     event_push_actions
-        #     event_reference_hashes
-        #     event_search
-        #     event_to_state_groups
-        #     events
-        #     rejections
-        #     room_depth
-        #     state_groups
-        #     state_groups_state
-
-        # we will build a temporary table listing the events so that we don't
-        # have to keep shovelling the list back and forth across the
-        # connection. Annoyingly the python sqlite driver commits the
-        # transaction on CREATE, so let's do this first.
-        #
-        # furthermore, we might already have the table from a previous (failed)
-        # purge attempt, so let's drop the table first.
+        parent_id = relation.get("event_id")
+        if not parent_id:
+            # Invalid relation
+            return
 
-        txn.execute("DROP TABLE IF EXISTS events_to_purge")
+        aggregation_key = relation.get("key")
 
-        txn.execute(
-            "CREATE TEMPORARY TABLE events_to_purge ("
-            "    event_id TEXT NOT NULL,"
-            "    should_delete BOOLEAN NOT NULL"
-            ")"
+        self.db.simple_insert_txn(
+            txn,
+            table="event_relations",
+            values={
+                "event_id": event.event_id,
+                "relates_to_id": parent_id,
+                "relation_type": rel_type,
+                "aggregation_key": aggregation_key,
+            },
         )
 
-        # First ensure that we're not about to delete all the forward extremeties
-        txn.execute(
-            "SELECT e.event_id, e.depth FROM events as e "
-            "INNER JOIN event_forward_extremities as f "
-            "ON e.event_id = f.event_id "
-            "AND e.room_id = f.room_id "
-            "WHERE f.room_id = ?",
-            (room_id,),
+        txn.call_after(self.store.get_relations_for_event.invalidate_many, (parent_id,))
+        txn.call_after(
+            self.store.get_aggregation_groups_for_event.invalidate_many, (parent_id,)
         )
-        rows = txn.fetchall()
-        max_depth = max(row[1] for row in rows)
-
-        if max_depth < token.topological:
-            # We need to ensure we don't delete all the events from the database
-            # otherwise we wouldn't be able to send any events (due to not
-            # having any backwards extremeties)
-            raise SynapseError(
-                400, "topological_ordering is greater than forward extremeties"
-            )
-
-        logger.info("[purge] looking for events to delete")
-
-        should_delete_expr = "state_key IS NULL"
-        should_delete_params = ()
-        if not delete_local_events:
-            should_delete_expr += " AND event_id NOT LIKE ?"
-
-            # We include the parameter twice since we use the expression twice
-            should_delete_params += ("%:" + self.hs.hostname, "%:" + self.hs.hostname)
 
-        should_delete_params += (room_id, token.topological)
+        if rel_type == RelationTypes.REPLACE:
+            txn.call_after(self.store.get_applicable_edit.invalidate, (parent_id,))
 
-        # Note that we insert events that are outliers and aren't going to be
-        # deleted, as nothing will happen to them.
-        txn.execute(
-            "INSERT INTO events_to_purge"
-            " SELECT event_id, %s"
-            " FROM events AS e LEFT JOIN state_events USING (event_id)"
-            " WHERE (NOT outlier OR (%s)) AND e.room_id = ? AND topological_ordering < ?"
-            % (should_delete_expr, should_delete_expr),
-            should_delete_params,
-        )
+    def _handle_redaction(self, txn, redacted_event_id):
+        """Handles receiving a redaction and checking whether we need to remove
+        any redacted relations from the database.
 
-        # We create the indices *after* insertion as that's a lot faster.
+        Args:
+            txn
+            redacted_event_id (str): The event that was redacted.
+        """
 
-        # create an index on should_delete because later we'll be looking for
-        # the should_delete / shouldn't_delete subsets
-        txn.execute(
-            "CREATE INDEX events_to_purge_should_delete"
-            " ON events_to_purge(should_delete)"
+        self.db.simple_delete_txn(
+            txn, table="event_relations", keyvalues={"event_id": redacted_event_id}
         )
 
-        # We do joins against events_to_purge for e.g. calculating state
-        # groups to purge, etc., so lets make an index.
-        txn.execute("CREATE INDEX events_to_purge_id ON events_to_purge(event_id)")
-
-        txn.execute("SELECT event_id, should_delete FROM events_to_purge")
-        event_rows = txn.fetchall()
-        logger.info(
-            "[purge] found %i events before cutoff, of which %i can be deleted",
-            len(event_rows),
-            sum(1 for e in event_rows if e[1]),
-        )
+    def _store_room_topic_txn(self, txn, event):
+        if hasattr(event, "content") and "topic" in event.content:
+            self.store_event_search_txn(
+                txn, event, "content.topic", event.content["topic"]
+            )
 
-        logger.info("[purge] Finding new backward extremities")
+    def _store_room_name_txn(self, txn, event):
+        if hasattr(event, "content") and "name" in event.content:
+            self.store_event_search_txn(
+                txn, event, "content.name", event.content["name"]
+            )
 
-        # We calculate the new entries for the backward extremeties by finding
-        # events to be purged that are pointed to by events we're not going to
-        # purge.
-        txn.execute(
-            "SELECT DISTINCT e.event_id FROM events_to_purge AS e"
-            " INNER JOIN event_edges AS ed ON e.event_id = ed.prev_event_id"
-            " LEFT JOIN events_to_purge AS ep2 ON ed.event_id = ep2.event_id"
-            " WHERE ep2.event_id IS NULL"
-        )
-        new_backwards_extrems = txn.fetchall()
+    def _store_room_message_txn(self, txn, event):
+        if hasattr(event, "content") and "body" in event.content:
+            self.store_event_search_txn(
+                txn, event, "content.body", event.content["body"]
+            )
 
-        logger.info("[purge] replacing backward extremities: %r", new_backwards_extrems)
+    def _store_retention_policy_for_room_txn(self, txn, event):
+        if hasattr(event, "content") and (
+            "min_lifetime" in event.content or "max_lifetime" in event.content
+        ):
+            if (
+                "min_lifetime" in event.content
+                and not isinstance(event.content.get("min_lifetime"), integer_types)
+            ) or (
+                "max_lifetime" in event.content
+                and not isinstance(event.content.get("max_lifetime"), integer_types)
+            ):
+                # Ignore the event if one of the value isn't an integer.
+                return
 
-        txn.execute(
-            "DELETE FROM event_backward_extremities WHERE room_id = ?", (room_id,)
-        )
+            self.db.simple_insert_txn(
+                txn=txn,
+                table="room_retention",
+                values={
+                    "room_id": event.room_id,
+                    "event_id": event.event_id,
+                    "min_lifetime": event.content.get("min_lifetime"),
+                    "max_lifetime": event.content.get("max_lifetime"),
+                },
+            )
 
-        # Update backward extremeties
-        txn.executemany(
-            "INSERT INTO event_backward_extremities (room_id, event_id)"
-            " VALUES (?, ?)",
-            [(room_id, event_id) for event_id, in new_backwards_extrems],
-        )
+            self.store._invalidate_cache_and_stream(
+                txn, self.store.get_retention_policy_for_room, (event.room_id,)
+            )
 
-        logger.info("[purge] finding state groups referenced by deleted events")
+    def store_event_search_txn(self, txn, event, key, value):
+        """Add event to the search table
 
-        # Get all state groups that are referenced by events that are to be
-        # deleted.
-        txn.execute(
-            """
-            SELECT DISTINCT state_group FROM events_to_purge
-            INNER JOIN event_to_state_groups USING (event_id)
+        Args:
+            txn (cursor):
+            event (EventBase):
+            key (str):
+            value (str):
         """
+        self.store.store_search_entries_txn(
+            txn,
+            (
+                SearchEntry(
+                    key=key,
+                    value=value,
+                    event_id=event.event_id,
+                    room_id=event.room_id,
+                    stream_ordering=event.internal_metadata.stream_ordering,
+                    origin_server_ts=event.origin_server_ts,
+                ),
+            ),
         )
 
-        referenced_state_groups = {sg for sg, in txn}
-        logger.info(
-            "[purge] found %i referenced state groups", len(referenced_state_groups)
-        )
+    def _set_push_actions_for_event_and_users_txn(
+        self, txn, events_and_contexts, all_events_and_contexts
+    ):
+        """Handles moving push actions from staging table to main
+        event_push_actions table for all events in `events_and_contexts`.
 
-        logger.info("[purge] removing events from event_to_state_groups")
-        txn.execute(
-            "DELETE FROM event_to_state_groups "
-            "WHERE event_id IN (SELECT event_id from events_to_purge)"
-        )
-        for event_id, _ in event_rows:
-            txn.call_after(self._get_state_group_for_event.invalidate, (event_id,))
+        Also ensures that all events in `all_events_and_contexts` are removed
+        from the push action staging area.
 
-        # Delete all remote non-state events
-        for table in (
-            "events",
-            "event_json",
-            "event_auth",
-            "event_edges",
-            "event_forward_extremities",
-            "event_reference_hashes",
-            "event_search",
-            "rejections",
-        ):
-            logger.info("[purge] removing events from %s", table)
+        Args:
+            events_and_contexts (list[(EventBase, EventContext)]): events
+                we are persisting
+            all_events_and_contexts (list[(EventBase, EventContext)]): all
+                events that we were going to persist. This includes events
+                we've already persisted, etc, that wouldn't appear in
+                events_and_context.
+        """
 
-            txn.execute(
-                "DELETE FROM %s WHERE event_id IN ("
-                "    SELECT event_id FROM events_to_purge WHERE should_delete"
-                ")" % (table,)
+        sql = """
+            INSERT INTO event_push_actions (
+                room_id, event_id, user_id, actions, stream_ordering,
+                topological_ordering, notif, highlight
             )
+            SELECT ?, event_id, user_id, actions, ?, ?, notif, highlight
+            FROM event_push_actions_staging
+            WHERE event_id = ?
+        """
 
-        # event_push_actions lacks an index on event_id, and has one on
-        # (room_id, event_id) instead.
-        for table in ("event_push_actions",):
-            logger.info("[purge] removing events from %s", table)
+        if events_and_contexts:
+            txn.executemany(
+                sql,
+                (
+                    (
+                        event.room_id,
+                        event.internal_metadata.stream_ordering,
+                        event.depth,
+                        event.event_id,
+                    )
+                    for event, _ in events_and_contexts
+                ),
+            )
 
-            txn.execute(
-                "DELETE FROM %s WHERE room_id = ? AND event_id IN ("
-                "    SELECT event_id FROM events_to_purge WHERE should_delete"
-                ")" % (table,),
-                (room_id,),
+        for event, _ in events_and_contexts:
+            user_ids = self.db.simple_select_onecol_txn(
+                txn,
+                table="event_push_actions_staging",
+                keyvalues={"event_id": event.event_id},
+                retcol="user_id",
             )
 
-        # Mark all state and own events as outliers
-        logger.info("[purge] marking remaining events as outliers")
-        txn.execute(
-            "UPDATE events SET outlier = ?"
-            " WHERE event_id IN ("
-            "    SELECT event_id FROM events_to_purge "
-            "    WHERE NOT should_delete"
-            ")",
-            (True,),
+            for uid in user_ids:
+                txn.call_after(
+                    self.store.get_unread_event_push_actions_by_room_for_user.invalidate_many,
+                    (event.room_id, uid),
+                )
+
+        # Now we delete the staging area for *all* events that were being
+        # persisted.
+        txn.executemany(
+            "DELETE FROM event_push_actions_staging WHERE event_id = ?",
+            ((event.event_id,) for event, _ in all_events_and_contexts),
         )
 
-        # synapse tries to take out an exclusive lock on room_depth whenever it
-        # persists events (because upsert), and once we run this update, we
-        # will block that for the rest of our transaction.
-        #
-        # So, let's stick it at the end so that we don't block event
-        # persistence.
-        #
-        # We do this by calculating the minimum depth of the backwards
-        # extremities. However, the events in event_backward_extremities
-        # are ones we don't have yet so we need to look at the events that
-        # point to it via event_edges table.
-        txn.execute(
-            """
-            SELECT COALESCE(MIN(depth), 0)
-            FROM event_backward_extremities AS eb
-            INNER JOIN event_edges AS eg ON eg.prev_event_id = eb.event_id
-            INNER JOIN events AS e ON e.event_id = eg.event_id
-            WHERE eb.room_id = ?
-        """,
+    def _remove_push_actions_for_event_id_txn(self, txn, room_id, event_id):
+        # Sad that we have to blow away the cache for the whole room here
+        txn.call_after(
+            self.store.get_unread_event_push_actions_by_room_for_user.invalidate_many,
             (room_id,),
         )
-        (min_depth,) = txn.fetchone()
-
-        logger.info("[purge] updating room_depth to %d", min_depth)
-
         txn.execute(
-            "UPDATE room_depth SET min_depth = ? WHERE room_id = ?",
-            (min_depth, room_id),
+            "DELETE FROM event_push_actions WHERE room_id = ? AND event_id = ?",
+            (room_id, event_id),
         )
 
-        # finally, drop the temp table. this will commit the txn in sqlite,
-        # so make sure to keep this actually last.
-        txn.execute("DROP TABLE events_to_purge")
-
-        logger.info("[purge] done")
-
-        return referenced_state_groups
-
-    def purge_room(self, room_id):
-        """Deletes all record of a room
+    def _store_rejections_txn(self, txn, event_id, reason):
+        self.db.simple_insert_txn(
+            txn,
+            table="rejections",
+            values={
+                "event_id": event_id,
+                "reason": reason,
+                "last_check": self._clock.time_msec(),
+            },
+        )
 
-        Args:
-            room_id (str)
+    def _store_event_state_mappings_txn(
+        self, txn, events_and_contexts: Iterable[Tuple[EventBase, EventContext]]
+    ):
+        state_groups = {}
+        for event, context in events_and_contexts:
+            if event.internal_metadata.is_outlier():
+                continue
 
-        Returns:
-            Deferred[List[int]]: The list of state groups to delete.
-        """
+            # if the event was rejected, just give it the same state as its
+            # predecessor.
+            if context.rejected:
+                state_groups[event.event_id] = context.state_group_before_event
+                continue
 
-        return self.db.runInteraction("purge_room", self._purge_room_txn, room_id)
+            state_groups[event.event_id] = context.state_group
 
-    def _purge_room_txn(self, txn, room_id):
-        # First we fetch all the state groups that should be deleted, before
-        # we delete that information.
-        txn.execute(
-            """
-                SELECT DISTINCT state_group FROM events
-                INNER JOIN event_to_state_groups USING(event_id)
-                WHERE events.room_id = ?
-            """,
-            (room_id,),
+        self.db.simple_insert_many_txn(
+            txn,
+            table="event_to_state_groups",
+            values=[
+                {"state_group": state_group_id, "event_id": event_id}
+                for event_id, state_group_id in iteritems(state_groups)
+            ],
         )
 
-        state_groups = [row[0] for row in txn]
-
-        # Now we delete tables which lack an index on room_id but have one on event_id
-        for table in (
-            "event_auth",
-            "event_edges",
-            "event_push_actions_staging",
-            "event_reference_hashes",
-            "event_relations",
-            "event_to_state_groups",
-            "redactions",
-            "rejections",
-            "state_events",
-        ):
-            logger.info("[purge] removing %s from %s", room_id, table)
-
-            txn.execute(
-                """
-                DELETE FROM %s WHERE event_id IN (
-                  SELECT event_id FROM events WHERE room_id=?
-                )
-                """
-                % (table,),
-                (room_id,),
+        for event_id, state_group_id in iteritems(state_groups):
+            txn.call_after(
+                self.store._get_state_group_for_event.prefill,
+                (event_id,),
+                state_group_id,
             )
 
-        # and finally, the tables with an index on room_id (or no useful index)
-        for table in (
-            "current_state_events",
-            "event_backward_extremities",
-            "event_forward_extremities",
-            "event_json",
-            "event_push_actions",
-            "event_search",
-            "events",
-            "group_rooms",
-            "public_room_list_stream",
-            "receipts_graph",
-            "receipts_linearized",
-            "room_aliases",
-            "room_depth",
-            "room_memberships",
-            "room_stats_state",
-            "room_stats_current",
-            "room_stats_historical",
-            "room_stats_earliest_token",
-            "rooms",
-            "stream_ordering_to_exterm",
-            "users_in_public_rooms",
-            "users_who_share_private_rooms",
-            # no useful index, but let's clear them anyway
-            "appservice_room_list",
-            "e2e_room_keys",
-            "event_push_summary",
-            "pusher_throttle",
-            "group_summary_rooms",
-            "local_invites",
-            "room_account_data",
-            "room_tags",
-            "local_current_membership",
-        ):
-            logger.info("[purge] removing %s from %s", room_id, table)
-            txn.execute("DELETE FROM %s WHERE room_id=?" % (table,), (room_id,))
-
-        # Other tables we do NOT need to clear out:
-        #
-        #  - blocked_rooms
-        #    This is important, to make sure that we don't accidentally rejoin a blocked
-        #    room after it was purged
-        #
-        #  - user_directory
-        #    This has a room_id column, but it is unused
-        #
-
-        # Other tables that we might want to consider clearing out include:
-        #
-        #  - event_reports
-        #       Given that these are intended for abuse management my initial
-        #       inclination is to leave them in place.
-        #
-        #  - current_state_delta_stream
-        #  - ex_outlier_stream
-        #  - room_tags_revisions
-        #       The problem with these is that they are largeish and there is no room_id
-        #       index on them. In any case we should be clearing out 'stream' tables
-        #       periodically anyway (#5888)
-
-        # TODO: we could probably usefully do a bunch of cache invalidation here
+    def _update_min_depth_for_room_txn(self, txn, room_id, depth):
+        min_depth = self.store._get_min_depth_interaction(txn, room_id)
 
-        logger.info("[purge] done")
-
-        return state_groups
-
-    async def is_event_after(self, event_id1, event_id2):
-        """Returns True if event_id1 is after event_id2 in the stream
-        """
-        to_1, so_1 = await self._get_event_ordering(event_id1)
-        to_2, so_2 = await self._get_event_ordering(event_id2)
-        return (to_1, so_1) > (to_2, so_2)
+        if min_depth is not None and depth >= min_depth:
+            return
 
-    @cachedInlineCallbacks(max_entries=5000)
-    def _get_event_ordering(self, event_id):
-        res = yield self.db.simple_select_one(
-            table="events",
-            retcols=["topological_ordering", "stream_ordering"],
-            keyvalues={"event_id": event_id},
-            allow_none=True,
+        self.db.simple_upsert_txn(
+            txn,
+            table="room_depth",
+            keyvalues={"room_id": room_id},
+            values={"min_depth": depth},
         )
 
-        if not res:
-            raise SynapseError(404, "Could not find event %s" % (event_id,))
-
-        return (int(res["topological_ordering"]), int(res["stream_ordering"]))
-
-    def insert_labels_for_event_txn(
-        self, txn, event_id, labels, room_id, topological_ordering
-    ):
-        """Store the mapping between an event's ID and its labels, with one row per
-        (event_id, label) tuple.
-
-        Args:
-            txn (LoggingTransaction): The transaction to execute.
-            event_id (str): The event's ID.
-            labels (list[str]): A list of text labels.
-            room_id (str): The ID of the room the event was sent to.
-            topological_ordering (int): The position of the event in the room's topology.
+    def _handle_mult_prev_events(self, txn, events):
         """
-        return self.db.simple_insert_many_txn(
-            txn=txn,
-            table="event_labels",
+        For the given event, update the event edges table and forward and
+        backward extremities tables.
+        """
+        self.db.simple_insert_many_txn(
+            txn,
+            table="event_edges",
             values=[
                 {
-                    "event_id": event_id,
-                    "label": label,
-                    "room_id": room_id,
-                    "topological_ordering": topological_ordering,
+                    "event_id": ev.event_id,
+                    "prev_event_id": e_id,
+                    "room_id": ev.room_id,
+                    "is_state": False,
                 }
-                for label in labels
+                for ev in events
+                for e_id in ev.prev_event_ids()
             ],
         )
 
-    def _insert_event_expiry_txn(self, txn, event_id, expiry_ts):
-        """Save the expiry timestamp associated with a given event ID.
-
-        Args:
-            txn (LoggingTransaction): The database transaction to use.
-            event_id (str): The event ID the expiry timestamp is associated with.
-            expiry_ts (int): The timestamp at which to expire (delete) the event.
-        """
-        return self.db.simple_insert_txn(
-            txn=txn,
-            table="event_expiry",
-            values={"event_id": event_id, "expiry_ts": expiry_ts},
-        )
-
-    @defer.inlineCallbacks
-    def expire_event(self, event_id):
-        """Retrieve and expire an event that has expired, and delete its associated
-        expiry timestamp. If the event can't be retrieved, delete its associated
-        timestamp so we don't try to expire it again in the future.
-
-        Args:
-             event_id (str): The ID of the event to delete.
-        """
-        # Try to retrieve the event's content from the database or the event cache.
-        event = yield self.get_event(event_id)
-
-        def delete_expired_event_txn(txn):
-            # Delete the expiry timestamp associated with this event from the database.
-            self._delete_event_expiry_txn(txn, event_id)
-
-            if not event:
-                # If we can't find the event, log a warning and delete the expiry date
-                # from the database so that we don't try to expire it again in the
-                # future.
-                logger.warning(
-                    "Can't expire event %s because we don't have it.", event_id
-                )
-                return
-
-            # Prune the event's dict then convert it to JSON.
-            pruned_json = encode_json(
-                prune_event_dict(event.room_version, event.get_dict())
-            )
-
-            # Update the event_json table to replace the event's JSON with the pruned
-            # JSON.
-            self._censor_event_txn(txn, event.event_id, pruned_json)
-
-            # We need to invalidate the event cache entry for this event because we
-            # changed its content in the database. We can't call
-            # self._invalidate_cache_and_stream because self.get_event_cache isn't of the
-            # right type.
-            txn.call_after(self._get_event_cache.invalidate, (event.event_id,))
-            # Send that invalidation to replication so that other workers also invalidate
-            # the event cache.
-            self._send_invalidation_to_replication(
-                txn, "_get_event_cache", (event.event_id,)
-            )
+        self._update_backward_extremeties(txn, events)
 
-        yield self.db.runInteraction("delete_expired_event", delete_expired_event_txn)
+    def _update_backward_extremeties(self, txn, events):
+        """Updates the event_backward_extremities tables based on the new/updated
+        events being persisted.
 
-    def _delete_event_expiry_txn(self, txn, event_id):
-        """Delete the expiry timestamp associated with an event ID without deleting the
-        actual event.
+        This is called for new events *and* for events that were outliers, but
+        are now being persisted as non-outliers.
 
-        Args:
-            txn (LoggingTransaction): The transaction to use to perform the deletion.
-            event_id (str): The event ID to delete the associated expiry timestamp of.
+        Forward extremities are handled when we first start persisting the events.
         """
-        return self.db.simple_delete_txn(
-            txn=txn, table="event_expiry", keyvalues={"event_id": event_id}
+        events_by_room = {}
+        for ev in events:
+            events_by_room.setdefault(ev.room_id, []).append(ev)
+
+        query = (
+            "INSERT INTO event_backward_extremities (event_id, room_id)"
+            " SELECT ?, ? WHERE NOT EXISTS ("
+            " SELECT 1 FROM event_backward_extremities"
+            " WHERE event_id = ? AND room_id = ?"
+            " )"
+            " AND NOT EXISTS ("
+            " SELECT 1 FROM events WHERE event_id = ? AND room_id = ? "
+            " AND outlier = ?"
+            " )"
         )
 
-    def get_next_event_to_expire(self):
-        """Retrieve the entry with the lowest expiry timestamp in the event_expiry
-        table, or None if there's no more event to expire.
-
-        Returns: Deferred[Optional[Tuple[str, int]]]
-            A tuple containing the event ID as its first element and an expiry timestamp
-            as its second one, if there's at least one row in the event_expiry table.
-            None otherwise.
-        """
-
-        def get_next_event_to_expire_txn(txn):
-            txn.execute(
-                """
-                SELECT event_id, expiry_ts FROM event_expiry
-                ORDER BY expiry_ts ASC LIMIT 1
-                """
-            )
-
-            return txn.fetchone()
-
-        return self.db.runInteraction(
-            desc="get_next_event_to_expire", func=get_next_event_to_expire_txn
+        txn.executemany(
+            query,
+            [
+                (e_id, ev.room_id, e_id, ev.room_id, e_id, ev.room_id, False)
+                for ev in events
+                for e_id in ev.prev_event_ids()
+                if not ev.internal_metadata.is_outlier()
+            ],
         )
 
-
-AllNewEventsResult = namedtuple(
-    "AllNewEventsResult",
-    [
-        "new_forward_events",
-        "new_backfill_events",
-        "forward_ex_outliers",
-        "backward_ex_outliers",
-    ],
-)
+        query = (
+            "DELETE FROM event_backward_extremities"
+            " WHERE event_id = ? AND room_id = ?"
+        )
+        txn.executemany(
+            query,
+            [
+                (ev.event_id, ev.room_id)
+                for ev in events
+                if not ev.internal_metadata.is_outlier()
+            ],
+        )
diff --git a/synapse/storage/data_stores/main/events_worker.py b/synapse/storage/data_stores/main/events_worker.py
index 73df6b33ba95..9130b74eb57c 100644
--- a/synapse/storage/data_stores/main/events_worker.py
+++ b/synapse/storage/data_stores/main/events_worker.py
@@ -27,7 +27,7 @@
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes
-from synapse.api.errors import NotFoundError
+from synapse.api.errors import NotFoundError, SynapseError
 from synapse.api.room_versions import (
     KNOWN_ROOM_VERSIONS,
     EventFormatVersions,
@@ -37,10 +37,12 @@
 from synapse.events.utils import prune_event
 from synapse.logging.context import PreserveLoggingContext, current_context
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause
 from synapse.storage.database import Database
+from synapse.storage.util.id_generators import StreamIdGenerator
 from synapse.types import get_domain_from_id
-from synapse.util.caches.descriptors import Cache
+from synapse.util.caches.descriptors import Cache, cached, cachedInlineCallbacks
 from synapse.util.iterutils import batch_iter
 from synapse.util.metrics import Measure
 
@@ -74,14 +76,50 @@ class EventsWorkerStore(SQLBaseStore):
     def __init__(self, database: Database, db_conn, hs):
         super(EventsWorkerStore, self).__init__(database, db_conn, hs)
 
+        if hs.config.worker_app is None:
+            # We are the process in charge of generating stream ids for events,
+            # so instantiate ID generators based on the database
+            self._stream_id_gen = StreamIdGenerator(
+                db_conn,
+                "events",
+                "stream_ordering",
+                extra_tables=[("local_invites", "stream_id")],
+            )
+            self._backfill_id_gen = StreamIdGenerator(
+                db_conn,
+                "events",
+                "stream_ordering",
+                step=-1,
+                extra_tables=[("ex_outlier_stream", "event_stream_ordering")],
+            )
+        else:
+            # Another process is in charge of persisting events and generating
+            # stream IDs: rely on the replication streams to let us know which
+            # IDs we can process.
+            self._stream_id_gen = SlavedIdTracker(db_conn, "events", "stream_ordering")
+            self._backfill_id_gen = SlavedIdTracker(
+                db_conn, "events", "stream_ordering", step=-1
+            )
+
         self._get_event_cache = Cache(
-            "*getEvent*", keylen=3, max_entries=hs.config.event_cache_size
+            "*getEvent*",
+            keylen=3,
+            max_entries=hs.config.caches.event_cache_size,
+            apply_cache_factor_from_config=False,
         )
 
         self._event_fetch_lock = threading.Condition()
         self._event_fetch_list = []
         self._event_fetch_ongoing = 0
 
+    def process_replication_rows(self, stream_name, instance_name, token, rows):
+        if stream_name == "events":
+            self._stream_id_gen.advance(token)
+        elif stream_name == "backfill":
+            self._backfill_id_gen.advance(-token)
+
+        super().process_replication_rows(stream_name, instance_name, token, rows)
+
     def get_received_ts(self, event_id):
         """Get received_ts (when it was persisted) for the event.
 
@@ -1154,4 +1192,152 @@ def get_deltas_for_stream_id_txn(txn, stream_id):
         rows = await self.db.runInteraction(
             "get_deltas_for_stream_id", get_deltas_for_stream_id_txn, to_token
         )
+
         return rows, to_token, True
+
+    @cached(num_args=5, max_entries=10)
+    def get_all_new_events(
+        self,
+        last_backfill_id,
+        last_forward_id,
+        current_backfill_id,
+        current_forward_id,
+        limit,
+    ):
+        """Get all the new events that have arrived at the server either as
+        new events or as backfilled events"""
+        have_backfill_events = last_backfill_id != current_backfill_id
+        have_forward_events = last_forward_id != current_forward_id
+
+        if not have_backfill_events and not have_forward_events:
+            return defer.succeed(AllNewEventsResult([], [], [], [], []))
+
+        def get_all_new_events_txn(txn):
+            sql = (
+                "SELECT e.stream_ordering, e.event_id, e.room_id, e.type,"
+                " state_key, redacts"
+                " FROM events AS e"
+                " LEFT JOIN redactions USING (event_id)"
+                " LEFT JOIN state_events USING (event_id)"
+                " WHERE ? < stream_ordering AND stream_ordering <= ?"
+                " ORDER BY stream_ordering ASC"
+                " LIMIT ?"
+            )
+            if have_forward_events:
+                txn.execute(sql, (last_forward_id, current_forward_id, limit))
+                new_forward_events = txn.fetchall()
+
+                if len(new_forward_events) == limit:
+                    upper_bound = new_forward_events[-1][0]
+                else:
+                    upper_bound = current_forward_id
+
+                sql = (
+                    "SELECT event_stream_ordering, event_id, state_group"
+                    " FROM ex_outlier_stream"
+                    " WHERE ? > event_stream_ordering"
+                    " AND event_stream_ordering >= ?"
+                    " ORDER BY event_stream_ordering DESC"
+                )
+                txn.execute(sql, (last_forward_id, upper_bound))
+                forward_ex_outliers = txn.fetchall()
+            else:
+                new_forward_events = []
+                forward_ex_outliers = []
+
+            sql = (
+                "SELECT -e.stream_ordering, e.event_id, e.room_id, e.type,"
+                " state_key, redacts"
+                " FROM events AS e"
+                " LEFT JOIN redactions USING (event_id)"
+                " LEFT JOIN state_events USING (event_id)"
+                " WHERE ? > stream_ordering AND stream_ordering >= ?"
+                " ORDER BY stream_ordering DESC"
+                " LIMIT ?"
+            )
+            if have_backfill_events:
+                txn.execute(sql, (-last_backfill_id, -current_backfill_id, limit))
+                new_backfill_events = txn.fetchall()
+
+                if len(new_backfill_events) == limit:
+                    upper_bound = new_backfill_events[-1][0]
+                else:
+                    upper_bound = current_backfill_id
+
+                sql = (
+                    "SELECT -event_stream_ordering, event_id, state_group"
+                    " FROM ex_outlier_stream"
+                    " WHERE ? > event_stream_ordering"
+                    " AND event_stream_ordering >= ?"
+                    " ORDER BY event_stream_ordering DESC"
+                )
+                txn.execute(sql, (-last_backfill_id, -upper_bound))
+                backward_ex_outliers = txn.fetchall()
+            else:
+                new_backfill_events = []
+                backward_ex_outliers = []
+
+            return AllNewEventsResult(
+                new_forward_events,
+                new_backfill_events,
+                forward_ex_outliers,
+                backward_ex_outliers,
+            )
+
+        return self.db.runInteraction("get_all_new_events", get_all_new_events_txn)
+
+    async def is_event_after(self, event_id1, event_id2):
+        """Returns True if event_id1 is after event_id2 in the stream
+        """
+        to_1, so_1 = await self._get_event_ordering(event_id1)
+        to_2, so_2 = await self._get_event_ordering(event_id2)
+        return (to_1, so_1) > (to_2, so_2)
+
+    @cachedInlineCallbacks(max_entries=5000)
+    def _get_event_ordering(self, event_id):
+        res = yield self.db.simple_select_one(
+            table="events",
+            retcols=["topological_ordering", "stream_ordering"],
+            keyvalues={"event_id": event_id},
+            allow_none=True,
+        )
+
+        if not res:
+            raise SynapseError(404, "Could not find event %s" % (event_id,))
+
+        return (int(res["topological_ordering"]), int(res["stream_ordering"]))
+
+    def get_next_event_to_expire(self):
+        """Retrieve the entry with the lowest expiry timestamp in the event_expiry
+        table, or None if there's no more event to expire.
+
+        Returns: Deferred[Optional[Tuple[str, int]]]
+            A tuple containing the event ID as its first element and an expiry timestamp
+            as its second one, if there's at least one row in the event_expiry table.
+            None otherwise.
+        """
+
+        def get_next_event_to_expire_txn(txn):
+            txn.execute(
+                """
+                SELECT event_id, expiry_ts FROM event_expiry
+                ORDER BY expiry_ts ASC LIMIT 1
+                """
+            )
+
+            return txn.fetchone()
+
+        return self.db.runInteraction(
+            desc="get_next_event_to_expire", func=get_next_event_to_expire_txn
+        )
+
+
+AllNewEventsResult = namedtuple(
+    "AllNewEventsResult",
+    [
+        "new_forward_events",
+        "new_backfill_events",
+        "forward_ex_outliers",
+        "backward_ex_outliers",
+    ],
+)
diff --git a/synapse/storage/data_stores/main/group_server.py b/synapse/storage/data_stores/main/group_server.py
index 0963e6c250b2..fb1361f1c197 100644
--- a/synapse/storage/data_stores/main/group_server.py
+++ b/synapse/storage/data_stores/main/group_server.py
@@ -68,24 +68,78 @@ def get_invited_users_in_group(self, group_id):
             desc="get_invited_users_in_group",
         )
 
-    def get_rooms_in_group(self, group_id, include_private=False):
+    def get_rooms_in_group(self, group_id: str, include_private: bool = False):
+        """Retrieve the rooms that belong to a given group. Does not return rooms that
+        lack members.
+
+        Args:
+            group_id: The ID of the group to query for rooms
+            include_private: Whether to return private rooms in results
+
+        Returns:
+            Deferred[List[Dict[str, str|bool]]]: A list of dictionaries, each in the
+            form of:
+
+            {
+              "room_id": "!a_room_id:example.com",  # The ID of the room
+              "is_public": False                    # Whether this is a public room or not
+            }
+        """
         # TODO: Pagination
 
-        keyvalues = {"group_id": group_id}
-        if not include_private:
-            keyvalues["is_public"] = True
+        def _get_rooms_in_group_txn(txn):
+            sql = """
+            SELECT room_id, is_public FROM group_rooms
+                WHERE group_id = ?
+                AND room_id IN (
+                    SELECT group_rooms.room_id FROM group_rooms
+                    LEFT JOIN room_stats_current ON
+                        group_rooms.room_id = room_stats_current.room_id
+                        AND joined_members > 0
+                        AND local_users_in_room > 0
+                    LEFT JOIN rooms ON
+                        group_rooms.room_id = rooms.room_id
+                        AND (room_version <> '') = ?
+                )
+            """
+            args = [group_id, False]
 
-        return self.db.simple_select_list(
-            table="group_rooms",
-            keyvalues=keyvalues,
-            retcols=("room_id", "is_public"),
-            desc="get_rooms_in_group",
-        )
+            if not include_private:
+                sql += " AND is_public = ?"
+                args += [True]
+
+            txn.execute(sql, args)
+
+            return [
+                {"room_id": room_id, "is_public": is_public}
+                for room_id, is_public in txn
+            ]
 
-    def get_rooms_for_summary_by_category(self, group_id, include_private=False):
+        return self.db.runInteraction("get_rooms_in_group", _get_rooms_in_group_txn)
+
+    def get_rooms_for_summary_by_category(
+        self, group_id: str, include_private: bool = False,
+    ):
         """Get the rooms and categories that should be included in a summary request
 
-        Returns ([rooms], [categories])
+        Args:
+            group_id: The ID of the group to query the summary for
+            include_private: Whether to return private rooms in results
+
+        Returns:
+            Deferred[Tuple[List, Dict]]: A tuple containing:
+
+                * A list of dictionaries with the keys:
+                    * "room_id": str, the room ID
+                    * "is_public": bool, whether the room is public
+                    * "category_id": str|None, the category ID if set, else None
+                    * "order": int, the sort order of rooms
+
+                * A dictionary with the key:
+                    * category_id (str): a dictionary with the keys:
+                        * "is_public": bool, whether the category is public
+                        * "profile": str, the category profile
+                        * "order": int, the sort order of rooms in this category
         """
 
         def _get_rooms_for_summary_txn(txn):
@@ -97,13 +151,23 @@ def _get_rooms_for_summary_txn(txn):
                 SELECT room_id, is_public, category_id, room_order
                 FROM group_summary_rooms
                 WHERE group_id = ?
+                AND room_id IN (
+                    SELECT group_rooms.room_id FROM group_rooms
+                    LEFT JOIN room_stats_current ON
+                        group_rooms.room_id = room_stats_current.room_id
+                        AND joined_members > 0
+                        AND local_users_in_room > 0
+                    LEFT JOIN rooms ON
+                        group_rooms.room_id = rooms.room_id
+                        AND (room_version <> '') = ?
+                )
             """
 
             if not include_private:
                 sql += " AND is_public = ?"
-                txn.execute(sql, (group_id, True))
+                txn.execute(sql, (group_id, False, True))
             else:
-                txn.execute(sql, (group_id,))
+                txn.execute(sql, (group_id, False))
 
             rooms = [
                 {
diff --git a/synapse/storage/data_stores/main/keys.py b/synapse/storage/data_stores/main/keys.py
index ba89c68c9f60..4e1642a27a59 100644
--- a/synapse/storage/data_stores/main/keys.py
+++ b/synapse/storage/data_stores/main/keys.py
@@ -17,8 +17,6 @@
 import itertools
 import logging
 
-import six
-
 from signedjson.key import decode_verify_key_bytes
 
 from synapse.storage._base import SQLBaseStore
@@ -28,12 +26,8 @@
 
 logger = logging.getLogger(__name__)
 
-# py2 sqlite has buffer hardcoded as only binary type, so we must use it,
-# despite being deprecated and removed in favor of memoryview
-if six.PY2:
-    db_binary_type = six.moves.builtins.buffer
-else:
-    db_binary_type = memoryview
+
+db_binary_type = memoryview
 
 
 class KeyStore(SQLBaseStore):
diff --git a/synapse/storage/data_stores/main/metrics.py b/synapse/storage/data_stores/main/metrics.py
new file mode 100644
index 000000000000..dad5bbc60261
--- /dev/null
+++ b/synapse/storage/data_stores/main/metrics.py
@@ -0,0 +1,128 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import typing
+from collections import Counter
+
+from twisted.internet import defer
+
+from synapse.metrics import BucketCollector
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.event_push_actions import (
+    EventPushActionsWorkerStore,
+)
+from synapse.storage.database import Database
+
+
+class ServerMetricsStore(EventPushActionsWorkerStore, SQLBaseStore):
+    """Functions to pull various metrics from the DB, for e.g. phone home
+    stats and prometheus metrics.
+    """
+
+    def __init__(self, database: Database, db_conn, hs):
+        super().__init__(database, db_conn, hs)
+
+        # Collect metrics on the number of forward extremities that exist.
+        # Counter of number of extremities to count
+        self._current_forward_extremities_amount = (
+            Counter()
+        )  # type: typing.Counter[int]
+
+        BucketCollector(
+            "synapse_forward_extremities",
+            lambda: self._current_forward_extremities_amount,
+            buckets=[1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"],
+        )
+
+        # Read the extrems every 60 minutes
+        def read_forward_extremities():
+            # run as a background process to make sure that the database transactions
+            # have a logcontext to report to
+            return run_as_background_process(
+                "read_forward_extremities", self._read_forward_extremities
+            )
+
+        hs.get_clock().looping_call(read_forward_extremities, 60 * 60 * 1000)
+
+    async def _read_forward_extremities(self):
+        def fetch(txn):
+            txn.execute(
+                """
+                select count(*) c from event_forward_extremities
+                group by room_id
+                """
+            )
+            return txn.fetchall()
+
+        res = await self.db.runInteraction("read_forward_extremities", fetch)
+        self._current_forward_extremities_amount = Counter([x[0] for x in res])
+
+    @defer.inlineCallbacks
+    def count_daily_messages(self):
+        """
+        Returns an estimate of the number of messages sent in the last day.
+
+        If it has been significantly less or more than one day since the last
+        call to this function, it will return None.
+        """
+
+        def _count_messages(txn):
+            sql = """
+                SELECT COALESCE(COUNT(*), 0) FROM events
+                WHERE type = 'm.room.message'
+                AND stream_ordering > ?
+            """
+            txn.execute(sql, (self.stream_ordering_day_ago,))
+            (count,) = txn.fetchone()
+            return count
+
+        ret = yield self.db.runInteraction("count_messages", _count_messages)
+        return ret
+
+    @defer.inlineCallbacks
+    def count_daily_sent_messages(self):
+        def _count_messages(txn):
+            # This is good enough as if you have silly characters in your own
+            # hostname then thats your own fault.
+            like_clause = "%:" + self.hs.hostname
+
+            sql = """
+                SELECT COALESCE(COUNT(*), 0) FROM events
+                WHERE type = 'm.room.message'
+                    AND sender LIKE ?
+                AND stream_ordering > ?
+            """
+
+            txn.execute(sql, (like_clause, self.stream_ordering_day_ago))
+            (count,) = txn.fetchone()
+            return count
+
+        ret = yield self.db.runInteraction("count_daily_sent_messages", _count_messages)
+        return ret
+
+    @defer.inlineCallbacks
+    def count_daily_active_rooms(self):
+        def _count(txn):
+            sql = """
+                SELECT COALESCE(COUNT(DISTINCT room_id), 0) FROM events
+                WHERE type = 'm.room.message'
+                AND stream_ordering > ?
+            """
+            txn.execute(sql, (self.stream_ordering_day_ago,))
+            (count,) = txn.fetchone()
+            return count
+
+        ret = yield self.db.runInteraction("count_daily_active_rooms", _count)
+        return ret
diff --git a/synapse/storage/data_stores/main/profile.py b/synapse/storage/data_stores/main/profile.py
index 2b52cf9c1a6d..bfc9369f0b58 100644
--- a/synapse/storage/data_stores/main/profile.py
+++ b/synapse/storage/data_stores/main/profile.py
@@ -110,7 +110,7 @@ def update_remote_profile_cache(self, user_id, displayname, avatar_url):
         return self.db.simple_update(
             table="remote_profile_cache",
             keyvalues={"user_id": user_id},
-            values={
+            updatevalues={
                 "displayname": displayname,
                 "avatar_url": avatar_url,
                 "last_check": self._clock.time_msec(),
diff --git a/synapse/storage/data_stores/main/purge_events.py b/synapse/storage/data_stores/main/purge_events.py
new file mode 100644
index 000000000000..a93e1ef19863
--- /dev/null
+++ b/synapse/storage/data_stores/main/purge_events.py
@@ -0,0 +1,399 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from typing import Any, Tuple
+
+from synapse.api.errors import SynapseError
+from synapse.storage._base import SQLBaseStore
+from synapse.storage.data_stores.main.state import StateGroupWorkerStore
+from synapse.types import RoomStreamToken
+
+logger = logging.getLogger(__name__)
+
+
+class PurgeEventsStore(StateGroupWorkerStore, SQLBaseStore):
+    def purge_history(self, room_id, token, delete_local_events):
+        """Deletes room history before a certain point
+
+        Args:
+            room_id (str):
+
+            token (str): A topological token to delete events before
+
+            delete_local_events (bool):
+                if True, we will delete local events as well as remote ones
+                (instead of just marking them as outliers and deleting their
+                state groups).
+
+        Returns:
+            Deferred[set[int]]: The set of state groups that are referenced by
+            deleted events.
+        """
+
+        return self.db.runInteraction(
+            "purge_history",
+            self._purge_history_txn,
+            room_id,
+            token,
+            delete_local_events,
+        )
+
+    def _purge_history_txn(self, txn, room_id, token_str, delete_local_events):
+        token = RoomStreamToken.parse(token_str)
+
+        # Tables that should be pruned:
+        #     event_auth
+        #     event_backward_extremities
+        #     event_edges
+        #     event_forward_extremities
+        #     event_json
+        #     event_push_actions
+        #     event_reference_hashes
+        #     event_search
+        #     event_to_state_groups
+        #     events
+        #     rejections
+        #     room_depth
+        #     state_groups
+        #     state_groups_state
+
+        # we will build a temporary table listing the events so that we don't
+        # have to keep shovelling the list back and forth across the
+        # connection. Annoyingly the python sqlite driver commits the
+        # transaction on CREATE, so let's do this first.
+        #
+        # furthermore, we might already have the table from a previous (failed)
+        # purge attempt, so let's drop the table first.
+
+        txn.execute("DROP TABLE IF EXISTS events_to_purge")
+
+        txn.execute(
+            "CREATE TEMPORARY TABLE events_to_purge ("
+            "    event_id TEXT NOT NULL,"
+            "    should_delete BOOLEAN NOT NULL"
+            ")"
+        )
+
+        # First ensure that we're not about to delete all the forward extremeties
+        txn.execute(
+            "SELECT e.event_id, e.depth FROM events as e "
+            "INNER JOIN event_forward_extremities as f "
+            "ON e.event_id = f.event_id "
+            "AND e.room_id = f.room_id "
+            "WHERE f.room_id = ?",
+            (room_id,),
+        )
+        rows = txn.fetchall()
+        max_depth = max(row[1] for row in rows)
+
+        if max_depth < token.topological:
+            # We need to ensure we don't delete all the events from the database
+            # otherwise we wouldn't be able to send any events (due to not
+            # having any backwards extremeties)
+            raise SynapseError(
+                400, "topological_ordering is greater than forward extremeties"
+            )
+
+        logger.info("[purge] looking for events to delete")
+
+        should_delete_expr = "state_key IS NULL"
+        should_delete_params = ()  # type: Tuple[Any, ...]
+        if not delete_local_events:
+            should_delete_expr += " AND event_id NOT LIKE ?"
+
+            # We include the parameter twice since we use the expression twice
+            should_delete_params += ("%:" + self.hs.hostname, "%:" + self.hs.hostname)
+
+        should_delete_params += (room_id, token.topological)
+
+        # Note that we insert events that are outliers and aren't going to be
+        # deleted, as nothing will happen to them.
+        txn.execute(
+            "INSERT INTO events_to_purge"
+            " SELECT event_id, %s"
+            " FROM events AS e LEFT JOIN state_events USING (event_id)"
+            " WHERE (NOT outlier OR (%s)) AND e.room_id = ? AND topological_ordering < ?"
+            % (should_delete_expr, should_delete_expr),
+            should_delete_params,
+        )
+
+        # We create the indices *after* insertion as that's a lot faster.
+
+        # create an index on should_delete because later we'll be looking for
+        # the should_delete / shouldn't_delete subsets
+        txn.execute(
+            "CREATE INDEX events_to_purge_should_delete"
+            " ON events_to_purge(should_delete)"
+        )
+
+        # We do joins against events_to_purge for e.g. calculating state
+        # groups to purge, etc., so lets make an index.
+        txn.execute("CREATE INDEX events_to_purge_id ON events_to_purge(event_id)")
+
+        txn.execute("SELECT event_id, should_delete FROM events_to_purge")
+        event_rows = txn.fetchall()
+        logger.info(
+            "[purge] found %i events before cutoff, of which %i can be deleted",
+            len(event_rows),
+            sum(1 for e in event_rows if e[1]),
+        )
+
+        logger.info("[purge] Finding new backward extremities")
+
+        # We calculate the new entries for the backward extremeties by finding
+        # events to be purged that are pointed to by events we're not going to
+        # purge.
+        txn.execute(
+            "SELECT DISTINCT e.event_id FROM events_to_purge AS e"
+            " INNER JOIN event_edges AS ed ON e.event_id = ed.prev_event_id"
+            " LEFT JOIN events_to_purge AS ep2 ON ed.event_id = ep2.event_id"
+            " WHERE ep2.event_id IS NULL"
+        )
+        new_backwards_extrems = txn.fetchall()
+
+        logger.info("[purge] replacing backward extremities: %r", new_backwards_extrems)
+
+        txn.execute(
+            "DELETE FROM event_backward_extremities WHERE room_id = ?", (room_id,)
+        )
+
+        # Update backward extremeties
+        txn.executemany(
+            "INSERT INTO event_backward_extremities (room_id, event_id)"
+            " VALUES (?, ?)",
+            [(room_id, event_id) for event_id, in new_backwards_extrems],
+        )
+
+        logger.info("[purge] finding state groups referenced by deleted events")
+
+        # Get all state groups that are referenced by events that are to be
+        # deleted.
+        txn.execute(
+            """
+            SELECT DISTINCT state_group FROM events_to_purge
+            INNER JOIN event_to_state_groups USING (event_id)
+        """
+        )
+
+        referenced_state_groups = {sg for sg, in txn}
+        logger.info(
+            "[purge] found %i referenced state groups", len(referenced_state_groups)
+        )
+
+        logger.info("[purge] removing events from event_to_state_groups")
+        txn.execute(
+            "DELETE FROM event_to_state_groups "
+            "WHERE event_id IN (SELECT event_id from events_to_purge)"
+        )
+        for event_id, _ in event_rows:
+            txn.call_after(self._get_state_group_for_event.invalidate, (event_id,))
+
+        # Delete all remote non-state events
+        for table in (
+            "events",
+            "event_json",
+            "event_auth",
+            "event_edges",
+            "event_forward_extremities",
+            "event_reference_hashes",
+            "event_search",
+            "rejections",
+        ):
+            logger.info("[purge] removing events from %s", table)
+
+            txn.execute(
+                "DELETE FROM %s WHERE event_id IN ("
+                "    SELECT event_id FROM events_to_purge WHERE should_delete"
+                ")" % (table,)
+            )
+
+        # event_push_actions lacks an index on event_id, and has one on
+        # (room_id, event_id) instead.
+        for table in ("event_push_actions",):
+            logger.info("[purge] removing events from %s", table)
+
+            txn.execute(
+                "DELETE FROM %s WHERE room_id = ? AND event_id IN ("
+                "    SELECT event_id FROM events_to_purge WHERE should_delete"
+                ")" % (table,),
+                (room_id,),
+            )
+
+        # Mark all state and own events as outliers
+        logger.info("[purge] marking remaining events as outliers")
+        txn.execute(
+            "UPDATE events SET outlier = ?"
+            " WHERE event_id IN ("
+            "    SELECT event_id FROM events_to_purge "
+            "    WHERE NOT should_delete"
+            ")",
+            (True,),
+        )
+
+        # synapse tries to take out an exclusive lock on room_depth whenever it
+        # persists events (because upsert), and once we run this update, we
+        # will block that for the rest of our transaction.
+        #
+        # So, let's stick it at the end so that we don't block event
+        # persistence.
+        #
+        # We do this by calculating the minimum depth of the backwards
+        # extremities. However, the events in event_backward_extremities
+        # are ones we don't have yet so we need to look at the events that
+        # point to it via event_edges table.
+        txn.execute(
+            """
+            SELECT COALESCE(MIN(depth), 0)
+            FROM event_backward_extremities AS eb
+            INNER JOIN event_edges AS eg ON eg.prev_event_id = eb.event_id
+            INNER JOIN events AS e ON e.event_id = eg.event_id
+            WHERE eb.room_id = ?
+        """,
+            (room_id,),
+        )
+        (min_depth,) = txn.fetchone()
+
+        logger.info("[purge] updating room_depth to %d", min_depth)
+
+        txn.execute(
+            "UPDATE room_depth SET min_depth = ? WHERE room_id = ?",
+            (min_depth, room_id),
+        )
+
+        # finally, drop the temp table. this will commit the txn in sqlite,
+        # so make sure to keep this actually last.
+        txn.execute("DROP TABLE events_to_purge")
+
+        logger.info("[purge] done")
+
+        return referenced_state_groups
+
+    def purge_room(self, room_id):
+        """Deletes all record of a room
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[List[int]]: The list of state groups to delete.
+        """
+
+        return self.db.runInteraction("purge_room", self._purge_room_txn, room_id)
+
+    def _purge_room_txn(self, txn, room_id):
+        # First we fetch all the state groups that should be deleted, before
+        # we delete that information.
+        txn.execute(
+            """
+                SELECT DISTINCT state_group FROM events
+                INNER JOIN event_to_state_groups USING(event_id)
+                WHERE events.room_id = ?
+            """,
+            (room_id,),
+        )
+
+        state_groups = [row[0] for row in txn]
+
+        # Now we delete tables which lack an index on room_id but have one on event_id
+        for table in (
+            "event_auth",
+            "event_edges",
+            "event_push_actions_staging",
+            "event_reference_hashes",
+            "event_relations",
+            "event_to_state_groups",
+            "redactions",
+            "rejections",
+            "state_events",
+        ):
+            logger.info("[purge] removing %s from %s", room_id, table)
+
+            txn.execute(
+                """
+                DELETE FROM %s WHERE event_id IN (
+                  SELECT event_id FROM events WHERE room_id=?
+                )
+                """
+                % (table,),
+                (room_id,),
+            )
+
+        # and finally, the tables with an index on room_id (or no useful index)
+        for table in (
+            "current_state_events",
+            "event_backward_extremities",
+            "event_forward_extremities",
+            "event_json",
+            "event_push_actions",
+            "event_search",
+            "events",
+            "group_rooms",
+            "public_room_list_stream",
+            "receipts_graph",
+            "receipts_linearized",
+            "room_aliases",
+            "room_depth",
+            "room_memberships",
+            "room_stats_state",
+            "room_stats_current",
+            "room_stats_historical",
+            "room_stats_earliest_token",
+            "rooms",
+            "stream_ordering_to_exterm",
+            "users_in_public_rooms",
+            "users_who_share_private_rooms",
+            # no useful index, but let's clear them anyway
+            "appservice_room_list",
+            "e2e_room_keys",
+            "event_push_summary",
+            "pusher_throttle",
+            "group_summary_rooms",
+            "local_invites",
+            "room_account_data",
+            "room_tags",
+            "local_current_membership",
+        ):
+            logger.info("[purge] removing %s from %s", room_id, table)
+            txn.execute("DELETE FROM %s WHERE room_id=?" % (table,), (room_id,))
+
+        # Other tables we do NOT need to clear out:
+        #
+        #  - blocked_rooms
+        #    This is important, to make sure that we don't accidentally rejoin a blocked
+        #    room after it was purged
+        #
+        #  - user_directory
+        #    This has a room_id column, but it is unused
+        #
+
+        # Other tables that we might want to consider clearing out include:
+        #
+        #  - event_reports
+        #       Given that these are intended for abuse management my initial
+        #       inclination is to leave them in place.
+        #
+        #  - current_state_delta_stream
+        #  - ex_outlier_stream
+        #  - room_tags_revisions
+        #       The problem with these is that they are largeish and there is no room_id
+        #       index on them. In any case we should be clearing out 'stream' tables
+        #       periodically anyway (#5888)
+
+        # TODO: we could probably usefully do a bunch of cache invalidation here
+
+        logger.info("[purge] done")
+
+        return state_groups
diff --git a/synapse/storage/data_stores/main/push_rule.py b/synapse/storage/data_stores/main/push_rule.py
index b3faafa0a44d..ef8f40959fa8 100644
--- a/synapse/storage/data_stores/main/push_rule.py
+++ b/synapse/storage/data_stores/main/push_rule.py
@@ -16,19 +16,23 @@
 
 import abc
 import logging
+from typing import Union
 
 from canonicaljson import json
 
 from twisted.internet import defer
 
 from synapse.push.baserules import list_with_base_rules
+from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.data_stores.main.appservice import ApplicationServiceWorkerStore
+from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
 from synapse.storage.data_stores.main.pusher import PusherWorkerStore
 from synapse.storage.data_stores.main.receipts import ReceiptsWorkerStore
 from synapse.storage.data_stores.main.roommember import RoomMemberWorkerStore
 from synapse.storage.database import Database
 from synapse.storage.push_rule import InconsistentRuleException, RuleNotFoundException
+from synapse.storage.util.id_generators import ChainedIdGenerator
 from synapse.util.caches.descriptors import cachedInlineCallbacks, cachedList
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
@@ -64,6 +68,7 @@ class PushRulesWorkerStore(
     ReceiptsWorkerStore,
     PusherWorkerStore,
     RoomMemberWorkerStore,
+    EventsWorkerStore,
     SQLBaseStore,
 ):
     """This is an abstract base class where subclasses must implement
@@ -77,6 +82,15 @@ class PushRulesWorkerStore(
     def __init__(self, database: Database, db_conn, hs):
         super(PushRulesWorkerStore, self).__init__(database, db_conn, hs)
 
+        if hs.config.worker.worker_app is None:
+            self._push_rules_stream_id_gen = ChainedIdGenerator(
+                self._stream_id_gen, db_conn, "push_rules_stream", "stream_id"
+            )  # type: Union[ChainedIdGenerator, SlavedIdTracker]
+        else:
+            self._push_rules_stream_id_gen = SlavedIdTracker(
+                db_conn, "push_rules_stream", "stream_id"
+            )
+
         push_rules_prefill, push_rules_id = self.db.get_cache_dict(
             db_conn,
             "push_rules_stream",
diff --git a/synapse/storage/data_stores/main/rejections.py b/synapse/storage/data_stores/main/rejections.py
index 1c07c7a425fc..27e5a2084a20 100644
--- a/synapse/storage/data_stores/main/rejections.py
+++ b/synapse/storage/data_stores/main/rejections.py
@@ -21,17 +21,6 @@
 
 
 class RejectionsStore(SQLBaseStore):
-    def _store_rejections_txn(self, txn, event_id, reason):
-        self.db.simple_insert_txn(
-            txn,
-            table="rejections",
-            values={
-                "event_id": event_id,
-                "reason": reason,
-                "last_check": self._clock.time_msec(),
-            },
-        )
-
     def get_rejection_reason(self, event_id):
         return self.db.simple_select_one_onecol(
             table="rejections",
diff --git a/synapse/storage/data_stores/main/relations.py b/synapse/storage/data_stores/main/relations.py
index 046c2b4845bb..7d477f8d0111 100644
--- a/synapse/storage/data_stores/main/relations.py
+++ b/synapse/storage/data_stores/main/relations.py
@@ -324,62 +324,4 @@ def _get_if_user_has_annotated_event(txn):
 
 
 class RelationsStore(RelationsWorkerStore):
-    def _handle_event_relations(self, txn, event):
-        """Handles inserting relation data during peristence of events
-
-        Args:
-            txn
-            event (EventBase)
-        """
-        relation = event.content.get("m.relates_to")
-        if not relation:
-            # No relations
-            return
-
-        rel_type = relation.get("rel_type")
-        if rel_type not in (
-            RelationTypes.ANNOTATION,
-            RelationTypes.REFERENCE,
-            RelationTypes.REPLACE,
-        ):
-            # Unknown relation type
-            return
-
-        parent_id = relation.get("event_id")
-        if not parent_id:
-            # Invalid relation
-            return
-
-        aggregation_key = relation.get("key")
-
-        self.db.simple_insert_txn(
-            txn,
-            table="event_relations",
-            values={
-                "event_id": event.event_id,
-                "relates_to_id": parent_id,
-                "relation_type": rel_type,
-                "aggregation_key": aggregation_key,
-            },
-        )
-
-        txn.call_after(self.get_relations_for_event.invalidate_many, (parent_id,))
-        txn.call_after(
-            self.get_aggregation_groups_for_event.invalidate_many, (parent_id,)
-        )
-
-        if rel_type == RelationTypes.REPLACE:
-            txn.call_after(self.get_applicable_edit.invalidate, (parent_id,))
-
-    def _handle_redaction(self, txn, redacted_event_id):
-        """Handles receiving a redaction and checking whether we need to remove
-        any redacted relations from the database.
-
-        Args:
-            txn
-            redacted_event_id (str): The event that was redacted.
-        """
-
-        self.db.simple_delete_txn(
-            txn, table="event_relations", keyvalues={"event_id": redacted_event_id}
-        )
+    pass
diff --git a/synapse/storage/data_stores/main/room.py b/synapse/storage/data_stores/main/room.py
index 147eba1df70e..46f643c6b904 100644
--- a/synapse/storage/data_stores/main/room.py
+++ b/synapse/storage/data_stores/main/room.py
@@ -21,8 +21,6 @@
 from enum import Enum
 from typing import Any, Dict, List, Optional, Tuple
 
-from six import integer_types
-
 from canonicaljson import json
 
 from twisted.internet import defer
@@ -98,6 +96,37 @@ def get_room(self, room_id):
             allow_none=True,
         )
 
+    def get_room_with_stats(self, room_id: str):
+        """Retrieve room with statistics.
+
+        Args:
+            room_id: The ID of the room to retrieve.
+        Returns:
+            A dict containing the room information, or None if the room is unknown.
+        """
+
+        def get_room_with_stats_txn(txn, room_id):
+            sql = """
+                SELECT room_id, state.name, state.canonical_alias, curr.joined_members,
+                  curr.local_users_in_room AS joined_local_members, rooms.room_version AS version,
+                  rooms.creator, state.encryption, state.is_federatable AS federatable,
+                  rooms.is_public AS public, state.join_rules, state.guest_access,
+                  state.history_visibility, curr.current_state_events AS state_events
+                FROM rooms
+                LEFT JOIN room_stats_state state USING (room_id)
+                LEFT JOIN room_stats_current curr USING (room_id)
+                WHERE room_id = ?
+                """
+            txn.execute(sql, [room_id])
+            res = self.db.cursor_to_dict(txn)[0]
+            res["federatable"] = bool(res["federatable"])
+            res["public"] = bool(res["public"])
+            return res
+
+        return self.db.runInteraction(
+            "get_room_with_stats", get_room_with_stats_txn, room_id
+        )
+
     def get_public_room_ids(self):
         return self.db.simple_select_onecol(
             table="rooms",
@@ -1271,53 +1300,6 @@ def f(txn):
 
         return self.db.runInteraction("get_rooms", f)
 
-    def _store_room_topic_txn(self, txn, event):
-        if hasattr(event, "content") and "topic" in event.content:
-            self.store_event_search_txn(
-                txn, event, "content.topic", event.content["topic"]
-            )
-
-    def _store_room_name_txn(self, txn, event):
-        if hasattr(event, "content") and "name" in event.content:
-            self.store_event_search_txn(
-                txn, event, "content.name", event.content["name"]
-            )
-
-    def _store_room_message_txn(self, txn, event):
-        if hasattr(event, "content") and "body" in event.content:
-            self.store_event_search_txn(
-                txn, event, "content.body", event.content["body"]
-            )
-
-    def _store_retention_policy_for_room_txn(self, txn, event):
-        if hasattr(event, "content") and (
-            "min_lifetime" in event.content or "max_lifetime" in event.content
-        ):
-            if (
-                "min_lifetime" in event.content
-                and not isinstance(event.content.get("min_lifetime"), integer_types)
-            ) or (
-                "max_lifetime" in event.content
-                and not isinstance(event.content.get("max_lifetime"), integer_types)
-            ):
-                # Ignore the event if one of the value isn't an integer.
-                return
-
-            self.db.simple_insert_txn(
-                txn=txn,
-                table="room_retention",
-                values={
-                    "room_id": event.room_id,
-                    "event_id": event.event_id,
-                    "min_lifetime": event.content.get("min_lifetime"),
-                    "max_lifetime": event.content.get("max_lifetime"),
-                },
-            )
-
-            self._invalidate_cache_and_stream(
-                txn, self.get_retention_policy_for_room, (event.room_id,)
-            )
-
     def add_event_report(
         self, room_id, event_id, user_id, reason, content, received_ts
     ):
diff --git a/synapse/storage/data_stores/main/roommember.py b/synapse/storage/data_stores/main/roommember.py
index e626b7f6f72d..1e9c85015274 100644
--- a/synapse/storage/data_stores/main/roommember.py
+++ b/synapse/storage/data_stores/main/roommember.py
@@ -45,7 +45,6 @@
 from synapse.util.caches import intern_string
 from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
 from synapse.util.metrics import Measure
-from synapse.util.stringutils import to_ascii
 
 logger = logging.getLogger(__name__)
 
@@ -153,16 +152,6 @@ def _check_safe_current_state_events_membership_updated_txn(self, txn):
                 self._check_safe_current_state_events_membership_updated_txn,
             )
 
-    @cachedInlineCallbacks(max_entries=100000, iterable=True, cache_context=True)
-    def get_hosts_in_room(self, room_id, cache_context):
-        """Returns the set of all hosts currently in the room
-        """
-        user_ids = yield self.get_users_in_room(
-            room_id, on_invalidate=cache_context.invalidate
-        )
-        hosts = frozenset(get_domain_from_id(user_id) for user_id in user_ids)
-        return hosts
-
     @cached(max_entries=100000, iterable=True)
     def get_users_in_room(self, room_id):
         return self.db.runInteraction(
@@ -189,7 +178,7 @@ def get_users_in_room_txn(self, txn, room_id):
             """
 
         txn.execute(sql, (room_id, Membership.JOIN))
-        return [to_ascii(r[0]) for r in txn]
+        return [r[0] for r in txn]
 
     @cached(max_entries=100000)
     def get_room_summary(self, room_id):
@@ -233,7 +222,7 @@ def _get_room_summary_txn(txn):
             txn.execute(sql, (room_id,))
             res = {}
             for count, membership in txn:
-                summary = res.setdefault(to_ascii(membership), MemberSummary([], count))
+                summary = res.setdefault(membership, MemberSummary([], count))
 
             # we order by membership and then fairly arbitrarily by event_id so
             # heroes are consistent
@@ -265,11 +254,11 @@ def _get_room_summary_txn(txn):
             # 6 is 5 (number of heroes) plus 1, in case one of them is the calling user.
             txn.execute(sql, (room_id, Membership.JOIN, Membership.INVITE, 6))
             for user_id, membership, event_id in txn:
-                summary = res[to_ascii(membership)]
+                summary = res[membership]
                 # we will always have a summary for this membership type at this
                 # point given the summary currently contains the counts.
                 members = summary.members
-                members.append((to_ascii(user_id), to_ascii(event_id)))
+                members.append((user_id, event_id))
 
             return res
 
@@ -594,13 +583,9 @@ def _get_joined_users_from_context(
             ev_entry = event_map.get(event_id)
             if ev_entry:
                 if ev_entry.event.membership == Membership.JOIN:
-                    users_in_room[to_ascii(ev_entry.event.state_key)] = ProfileInfo(
-                        display_name=to_ascii(
-                            ev_entry.event.content.get("displayname", None)
-                        ),
-                        avatar_url=to_ascii(
-                            ev_entry.event.content.get("avatar_url", None)
-                        ),
+                    users_in_room[ev_entry.event.state_key] = ProfileInfo(
+                        display_name=ev_entry.event.content.get("displayname", None),
+                        avatar_url=ev_entry.event.content.get("avatar_url", None),
                     )
             else:
                 missing_member_event_ids.append(event_id)
@@ -614,9 +599,9 @@ def _get_joined_users_from_context(
         if event is not None and event.type == EventTypes.Member:
             if event.membership == Membership.JOIN:
                 if event.event_id in member_event_ids:
-                    users_in_room[to_ascii(event.state_key)] = ProfileInfo(
-                        display_name=to_ascii(event.content.get("displayname", None)),
-                        avatar_url=to_ascii(event.content.get("avatar_url", None)),
+                    users_in_room[event.state_key] = ProfileInfo(
+                        display_name=event.content.get("displayname", None),
+                        avatar_url=event.content.get("avatar_url", None),
                     )
 
         return users_in_room
@@ -1061,96 +1046,6 @@ class RoomMemberStore(RoomMemberWorkerStore, RoomMemberBackgroundUpdateStore):
     def __init__(self, database: Database, db_conn, hs):
         super(RoomMemberStore, self).__init__(database, db_conn, hs)
 
-    def _store_room_members_txn(self, txn, events, backfilled):
-        """Store a room member in the database.
-        """
-        self.db.simple_insert_many_txn(
-            txn,
-            table="room_memberships",
-            values=[
-                {
-                    "event_id": event.event_id,
-                    "user_id": event.state_key,
-                    "sender": event.user_id,
-                    "room_id": event.room_id,
-                    "membership": event.membership,
-                    "display_name": event.content.get("displayname", None),
-                    "avatar_url": event.content.get("avatar_url", None),
-                }
-                for event in events
-            ],
-        )
-
-        for event in events:
-            txn.call_after(
-                self._membership_stream_cache.entity_has_changed,
-                event.state_key,
-                event.internal_metadata.stream_ordering,
-            )
-            txn.call_after(
-                self.get_invited_rooms_for_local_user.invalidate, (event.state_key,)
-            )
-
-            # We update the local_invites table only if the event is "current",
-            # i.e., its something that has just happened. If the event is an
-            # outlier it is only current if its an "out of band membership",
-            # like a remote invite or a rejection of a remote invite.
-            is_new_state = not backfilled and (
-                not event.internal_metadata.is_outlier()
-                or event.internal_metadata.is_out_of_band_membership()
-            )
-            is_mine = self.hs.is_mine_id(event.state_key)
-            if is_new_state and is_mine:
-                if event.membership == Membership.INVITE:
-                    self.db.simple_insert_txn(
-                        txn,
-                        table="local_invites",
-                        values={
-                            "event_id": event.event_id,
-                            "invitee": event.state_key,
-                            "inviter": event.sender,
-                            "room_id": event.room_id,
-                            "stream_id": event.internal_metadata.stream_ordering,
-                        },
-                    )
-                else:
-                    sql = (
-                        "UPDATE local_invites SET stream_id = ?, replaced_by = ? WHERE"
-                        " room_id = ? AND invitee = ? AND locally_rejected is NULL"
-                        " AND replaced_by is NULL"
-                    )
-
-                    txn.execute(
-                        sql,
-                        (
-                            event.internal_metadata.stream_ordering,
-                            event.event_id,
-                            event.room_id,
-                            event.state_key,
-                        ),
-                    )
-
-                # We also update the `local_current_membership` table with
-                # latest invite info. This will usually get updated by the
-                # `current_state_events` handling, unless its an outlier.
-                if event.internal_metadata.is_outlier():
-                    # This should only happen for out of band memberships, so
-                    # we add a paranoia check.
-                    assert event.internal_metadata.is_out_of_band_membership()
-
-                    self.db.simple_upsert_txn(
-                        txn,
-                        table="local_current_membership",
-                        keyvalues={
-                            "room_id": event.room_id,
-                            "user_id": event.state_key,
-                        },
-                        values={
-                            "event_id": event.event_id,
-                            "membership": event.membership,
-                        },
-                    )
-
     @defer.inlineCallbacks
     def locally_reject_invite(self, user_id, room_id):
         sql = (
diff --git a/synapse/storage/data_stores/main/schema/delta/58/05cache_instance.sql.postgres b/synapse/storage/data_stores/main/schema/delta/58/05cache_instance.sql.postgres
new file mode 100644
index 000000000000..aa46eb0e1033
--- /dev/null
+++ b/synapse/storage/data_stores/main/schema/delta/58/05cache_instance.sql.postgres
@@ -0,0 +1,30 @@
+/* Copyright 2020 The Matrix.org Foundation C.I.C
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+-- We keep the old table here to enable us to roll back. It doesn't matter
+-- that we have dropped all the data here.
+TRUNCATE cache_invalidation_stream;
+
+CREATE TABLE cache_invalidation_stream_by_instance (
+    stream_id       BIGINT NOT NULL,
+    instance_name   TEXT NOT NULL,
+    cache_func      TEXT NOT NULL,
+    keys            TEXT[],
+    invalidation_ts BIGINT
+);
+
+CREATE UNIQUE INDEX cache_invalidation_stream_by_instance_id ON cache_invalidation_stream_by_instance(stream_id);
+
+CREATE SEQUENCE cache_invalidation_stream_seq;
diff --git a/synapse/storage/data_stores/main/search.py b/synapse/storage/data_stores/main/search.py
index 2c50e04515ff..3c38b1ac5088 100644
--- a/synapse/storage/data_stores/main/search.py
+++ b/synapse/storage/data_stores/main/search.py
@@ -37,7 +37,55 @@
 )
 
 
-class SearchBackgroundUpdateStore(SQLBaseStore):
+class SearchWorkerStore(SQLBaseStore):
+    def store_search_entries_txn(self, txn, entries):
+        """Add entries to the search table
+
+        Args:
+            txn (cursor):
+            entries (iterable[SearchEntry]):
+                entries to be added to the table
+        """
+        if not self.hs.config.enable_search:
+            return
+        if isinstance(self.database_engine, PostgresEngine):
+            sql = (
+                "INSERT INTO event_search"
+                " (event_id, room_id, key, vector, stream_ordering, origin_server_ts)"
+                " VALUES (?,?,?,to_tsvector('english', ?),?,?)"
+            )
+
+            args = (
+                (
+                    entry.event_id,
+                    entry.room_id,
+                    entry.key,
+                    entry.value,
+                    entry.stream_ordering,
+                    entry.origin_server_ts,
+                )
+                for entry in entries
+            )
+
+            txn.executemany(sql, args)
+
+        elif isinstance(self.database_engine, Sqlite3Engine):
+            sql = (
+                "INSERT INTO event_search (event_id, room_id, key, value)"
+                " VALUES (?,?,?,?)"
+            )
+            args = (
+                (entry.event_id, entry.room_id, entry.key, entry.value)
+                for entry in entries
+            )
+
+            txn.executemany(sql, args)
+        else:
+            # This should be unreachable.
+            raise Exception("Unrecognized database engine")
+
+
+class SearchBackgroundUpdateStore(SearchWorkerStore):
 
     EVENT_SEARCH_UPDATE_NAME = "event_search"
     EVENT_SEARCH_ORDER_UPDATE_NAME = "event_search_order"
@@ -296,80 +344,11 @@ def reindex_search_txn(txn):
 
         return num_rows
 
-    def store_search_entries_txn(self, txn, entries):
-        """Add entries to the search table
-
-        Args:
-            txn (cursor):
-            entries (iterable[SearchEntry]):
-                entries to be added to the table
-        """
-        if not self.hs.config.enable_search:
-            return
-        if isinstance(self.database_engine, PostgresEngine):
-            sql = (
-                "INSERT INTO event_search"
-                " (event_id, room_id, key, vector, stream_ordering, origin_server_ts)"
-                " VALUES (?,?,?,to_tsvector('english', ?),?,?)"
-            )
-
-            args = (
-                (
-                    entry.event_id,
-                    entry.room_id,
-                    entry.key,
-                    entry.value,
-                    entry.stream_ordering,
-                    entry.origin_server_ts,
-                )
-                for entry in entries
-            )
-
-            txn.executemany(sql, args)
-
-        elif isinstance(self.database_engine, Sqlite3Engine):
-            sql = (
-                "INSERT INTO event_search (event_id, room_id, key, value)"
-                " VALUES (?,?,?,?)"
-            )
-            args = (
-                (entry.event_id, entry.room_id, entry.key, entry.value)
-                for entry in entries
-            )
-
-            txn.executemany(sql, args)
-        else:
-            # This should be unreachable.
-            raise Exception("Unrecognized database engine")
-
 
 class SearchStore(SearchBackgroundUpdateStore):
     def __init__(self, database: Database, db_conn, hs):
         super(SearchStore, self).__init__(database, db_conn, hs)
 
-    def store_event_search_txn(self, txn, event, key, value):
-        """Add event to the search table
-
-        Args:
-            txn (cursor):
-            event (EventBase):
-            key (str):
-            value (str):
-        """
-        self.store_search_entries_txn(
-            txn,
-            (
-                SearchEntry(
-                    key=key,
-                    value=value,
-                    event_id=event.event_id,
-                    room_id=event.room_id,
-                    stream_ordering=event.internal_metadata.stream_ordering,
-                    origin_server_ts=event.origin_server_ts,
-                ),
-            ),
-        )
-
     @defer.inlineCallbacks
     def search_msgs(self, room_ids, search_term, keys):
         """Performs a full text search over events with given keys.
diff --git a/synapse/storage/data_stores/main/signatures.py b/synapse/storage/data_stores/main/signatures.py
index 563216b63c92..36244d9f5da7 100644
--- a/synapse/storage/data_stores/main/signatures.py
+++ b/synapse/storage/data_stores/main/signatures.py
@@ -13,23 +13,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import six
-
 from unpaddedbase64 import encode_base64
 
 from twisted.internet import defer
 
-from synapse.crypto.event_signing import compute_event_reference_hash
 from synapse.storage._base import SQLBaseStore
 from synapse.util.caches.descriptors import cached, cachedList
 
-# py2 sqlite has buffer hardcoded as only binary type, so we must use it,
-# despite being deprecated and removed in favor of memoryview
-if six.PY2:
-    db_binary_type = six.moves.builtins.buffer
-else:
-    db_binary_type = memoryview
-
 
 class SignatureWorkerStore(SQLBaseStore):
     @cached()
@@ -79,23 +69,3 @@ def _get_event_reference_hashes_txn(self, txn, event_id):
 
 class SignatureStore(SignatureWorkerStore):
     """Persistence for event signatures and hashes"""
-
-    def _store_event_reference_hashes_txn(self, txn, events):
-        """Store a hash for a PDU
-        Args:
-            txn (cursor):
-            events (list): list of Events.
-        """
-
-        vals = []
-        for event in events:
-            ref_alg, ref_hash_bytes = compute_event_reference_hash(event)
-            vals.append(
-                {
-                    "event_id": event.event_id,
-                    "algorithm": ref_alg,
-                    "hash": db_binary_type(ref_hash_bytes),
-                }
-            )
-
-        self.db.simple_insert_many_txn(txn, table="event_reference_hashes", values=vals)
diff --git a/synapse/storage/data_stores/main/state.py b/synapse/storage/data_stores/main/state.py
index 3a3b9a8e7274..347cc5077809 100644
--- a/synapse/storage/data_stores/main/state.py
+++ b/synapse/storage/data_stores/main/state.py
@@ -16,17 +16,12 @@
 import collections.abc
 import logging
 from collections import namedtuple
-from typing import Iterable, Tuple
-
-from six import iteritems
 
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import NotFoundError, UnsupportedRoomVersionError
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion
-from synapse.events import EventBase
-from synapse.events.snapshot import EventContext
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
 from synapse.storage.data_stores.main.roommember import RoomMemberWorkerStore
@@ -34,7 +29,6 @@
 from synapse.storage.state import StateFilter
 from synapse.util.caches import intern_string
 from synapse.util.caches.descriptors import cached, cachedList
-from synapse.util.stringutils import to_ascii
 
 logger = logging.getLogger(__name__)
 
@@ -190,9 +184,7 @@ def _get_current_state_ids_txn(txn):
                 (room_id,),
             )
 
-            return {
-                (intern_string(r[0]), intern_string(r[1])): to_ascii(r[2]) for r in txn
-            }
+            return {(intern_string(r[0]), intern_string(r[1])): r[2] for r in txn}
 
         return self.db.runInteraction(
             "get_current_state_ids", _get_current_state_ids_txn
@@ -473,33 +465,3 @@ class StateStore(StateGroupWorkerStore, MainStateBackgroundUpdateStore):
 
     def __init__(self, database: Database, db_conn, hs):
         super(StateStore, self).__init__(database, db_conn, hs)
-
-    def _store_event_state_mappings_txn(
-        self, txn, events_and_contexts: Iterable[Tuple[EventBase, EventContext]]
-    ):
-        state_groups = {}
-        for event, context in events_and_contexts:
-            if event.internal_metadata.is_outlier():
-                continue
-
-            # if the event was rejected, just give it the same state as its
-            # predecessor.
-            if context.rejected:
-                state_groups[event.event_id] = context.state_group_before_event
-                continue
-
-            state_groups[event.event_id] = context.state_group
-
-        self.db.simple_insert_many_txn(
-            txn,
-            table="event_to_state_groups",
-            values=[
-                {"state_group": state_group_id, "event_id": event_id}
-                for event_id, state_group_id in iteritems(state_groups)
-            ],
-        )
-
-        for event_id, state_group_id in iteritems(state_groups):
-            txn.call_after(
-                self._get_state_group_for_event.prefill, (event_id,), state_group_id
-            )
diff --git a/synapse/storage/data_stores/main/transactions.py b/synapse/storage/data_stores/main/transactions.py
index 5b07c2fbc0c6..a9bf457939f1 100644
--- a/synapse/storage/data_stores/main/transactions.py
+++ b/synapse/storage/data_stores/main/transactions.py
@@ -16,8 +16,6 @@
 import logging
 from collections import namedtuple
 
-import six
-
 from canonicaljson import encode_canonical_json
 
 from twisted.internet import defer
@@ -27,12 +25,7 @@
 from synapse.storage.database import Database
 from synapse.util.caches.expiringcache import ExpiringCache
 
-# py2 sqlite has buffer hardcoded as only binary type, so we must use it,
-# despite being deprecated and removed in favor of memoryview
-if six.PY2:
-    db_binary_type = six.moves.builtins.buffer
-else:
-    db_binary_type = memoryview
+db_binary_type = memoryview
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/storage/data_stores/state/store.py b/synapse/storage/data_stores/state/store.py
index 57a526766346..f3ad1e4369a6 100644
--- a/synapse/storage/data_stores/state/store.py
+++ b/synapse/storage/data_stores/state/store.py
@@ -28,7 +28,6 @@
 from synapse.storage.database import Database
 from synapse.storage.state import StateFilter
 from synapse.types import StateMap
-from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.descriptors import cached
 from synapse.util.caches.dictionary_cache import DictionaryCache
 
@@ -90,11 +89,10 @@ def __init__(self, database: Database, db_conn, hs):
         self._state_group_cache = DictionaryCache(
             "*stateGroupCache*",
             # TODO: this hasn't been tuned yet
-            50000 * get_cache_factor_for("stateGroupCache"),
+            50000,
         )
         self._state_group_members_cache = DictionaryCache(
-            "*stateGroupMembersCache*",
-            500000 * get_cache_factor_for("stateGroupMembersCache"),
+            "*stateGroupMembersCache*", 500000,
         )
 
     @cached(max_entries=10000, iterable=True)
diff --git a/synapse/storage/database.py b/synapse/storage/database.py
index c3d086342976..9947dbce7787 100644
--- a/synapse/storage/database.py
+++ b/synapse/storage/database.py
@@ -50,7 +50,6 @@
 from synapse.storage.engines import BaseDatabaseEngine, PostgresEngine, Sqlite3Engine
 from synapse.storage.types import Connection, Cursor
 from synapse.types import Collection
-from synapse.util.stringutils import exception_to_unicode
 
 logger = logging.getLogger(__name__)
 
@@ -424,20 +423,14 @@ def new_transaction(
                     # This can happen if the database disappears mid
                     # transaction.
                     logger.warning(
-                        "[TXN OPERROR] {%s} %s %d/%d",
-                        name,
-                        exception_to_unicode(e),
-                        i,
-                        N,
+                        "[TXN OPERROR] {%s} %s %d/%d", name, e, i, N,
                     )
                     if i < N:
                         i += 1
                         try:
                             conn.rollback()
                         except self.engine.module.Error as e1:
-                            logger.warning(
-                                "[TXN EROLL] {%s} %s", name, exception_to_unicode(e1)
-                            )
+                            logger.warning("[TXN EROLL] {%s} %s", name, e1)
                         continue
                     raise
                 except self.engine.module.DatabaseError as e:
@@ -449,9 +442,7 @@ def new_transaction(
                                 conn.rollback()
                             except self.engine.module.Error as e1:
                                 logger.warning(
-                                    "[TXN EROLL] {%s} %s",
-                                    name,
-                                    exception_to_unicode(e1),
+                                    "[TXN EROLL] {%s} %s", name, e1,
                                 )
                             continue
                     raise
diff --git a/synapse/storage/persist_events.py b/synapse/storage/persist_events.py
index 0f9ac1cf0973..12e1ffb9a2f2 100644
--- a/synapse/storage/persist_events.py
+++ b/synapse/storage/persist_events.py
@@ -23,7 +23,6 @@
 from six import iteritems
 from six.moves import range
 
-import attr
 from prometheus_client import Counter, Histogram
 
 from twisted.internet import defer
@@ -35,6 +34,7 @@
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.state import StateResolutionStore
 from synapse.storage.data_stores import DataStores
+from synapse.storage.data_stores.main.events import DeltaState
 from synapse.types import StateMap
 from synapse.util.async_helpers import ObservableDeferred
 from synapse.util.metrics import Measure
@@ -73,22 +73,6 @@
 )
 
 
-@attr.s(slots=True)
-class DeltaState:
-    """Deltas to use to update the `current_state_events` table.
-
-    Attributes:
-        to_delete: List of type/state_keys to delete from current state
-        to_insert: Map of state to upsert into current state
-        no_longer_in_room: The server is not longer in the room, so the room
-            should e.g. be removed from `current_state_events` table.
-    """
-
-    to_delete = attr.ib(type=List[Tuple[str, str]])
-    to_insert = attr.ib(type=StateMap[str])
-    no_longer_in_room = attr.ib(type=bool, default=False)
-
-
 class _EventPeristenceQueue(object):
     """Queues up events so that they can be persisted in bulk with only one
     concurrent transaction per room.
@@ -205,6 +189,7 @@ def __init__(self, hs, stores: DataStores):
         # store for now.
         self.main_store = stores.main
         self.state_store = stores.state
+        self.persist_events_store = stores.persist_events
 
         self._clock = hs.get_clock()
         self.is_mine_id = hs.is_mine_id
@@ -445,7 +430,7 @@ async def _persist_events(
                         if current_state is not None:
                             current_state_for_room[room_id] = current_state
 
-            await self.main_store._persist_events_and_state_updates(
+            await self.persist_events_store._persist_events_and_state_updates(
                 chunk,
                 current_state_for_room=current_state_for_room,
                 state_delta_for_room=state_delta_for_room,
@@ -491,13 +476,15 @@ async def _calculate_new_extremities(
         )
 
         # Remove any events which are prev_events of any existing events.
-        existing_prevs = await self.main_store._get_events_which_are_prevs(result)
+        existing_prevs = await self.persist_events_store._get_events_which_are_prevs(
+            result
+        )
         result.difference_update(existing_prevs)
 
         # Finally handle the case where the new events have soft-failed prev
         # events. If they do we need to remove them and their prev events,
         # otherwise we end up with dangling extremities.
-        existing_prevs = await self.main_store._get_prevs_before_rejected(
+        existing_prevs = await self.persist_events_store._get_prevs_before_rejected(
             e_id for event in new_events for e_id in event.prev_event_ids()
         )
         result.difference_update(existing_prevs)
@@ -753,8 +740,8 @@ async def _is_server_still_joined(
         # whose state has changed as we've already their new state above.
         users_to_ignore = [
             state_key
-            for _, state_key in itertools.chain(delta.to_insert, delta.to_delete)
-            if self.is_mine_id(state_key)
+            for typ, state_key in itertools.chain(delta.to_insert, delta.to_delete)
+            if typ == EventTypes.Member and self.is_mine_id(state_key)
         ]
 
         if await self.main_store.is_local_host_in_room_ignoring_users(
diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py
index 1712932f319d..640f2425846d 100644
--- a/synapse/storage/prepare_database.py
+++ b/synapse/storage/prepare_database.py
@@ -29,6 +29,8 @@
 
 # Remember to update this number every time a change is made to database
 # schema files, so the users will be informed on server restarts.
+# XXX: If you're about to bump this to 59 (or higher) please create an update
+# that drops the unused `cache_invalidation_stream` table, as per #7436!
 SCHEMA_VERSION = 58
 
 dir_path = os.path.abspath(os.path.dirname(__file__))
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py
index 9d851beaa5f9..f89ce0bed2a8 100644
--- a/synapse/storage/util/id_generators.py
+++ b/synapse/storage/util/id_generators.py
@@ -16,6 +16,11 @@
 import contextlib
 import threading
 from collections import deque
+from typing import Dict, Set, Tuple
+
+from typing_extensions import Deque
+
+from synapse.storage.database import Database, LoggingTransaction
 
 
 class IdGenerator(object):
@@ -87,7 +92,7 @@ def __init__(self, db_conn, table, column, extra_tables=[], step=1):
             self._current = (max if step > 0 else min)(
                 self._current, _load_current_id(db_conn, table, column, step)
             )
-        self._unfinished_ids = deque()
+        self._unfinished_ids = deque()  # type: Deque[int]
 
     def get_next(self):
         """
@@ -161,9 +166,10 @@ class ChainedIdGenerator(object):
 
     def __init__(self, chained_generator, db_conn, table, column):
         self.chained_generator = chained_generator
+        self._table = table
         self._lock = threading.Lock()
         self._current_max = _load_current_id(db_conn, table, column)
-        self._unfinished_ids = deque()
+        self._unfinished_ids = deque()  # type: Deque[Tuple[int, int]]
 
     def get_next(self):
         """
@@ -198,3 +204,173 @@ def get_current_token(self):
                 return stream_id - 1, chained_id
 
             return self._current_max, self.chained_generator.get_current_token()
+
+    def advance(self, token: int):
+        """Stub implementation for advancing the token when receiving updates
+        over replication; raises an exception as this instance should be the
+        only source of updates.
+        """
+
+        raise Exception(
+            "Attempted to advance token on source for table %r", self._table
+        )
+
+
+class MultiWriterIdGenerator:
+    """An ID generator that tracks a stream that can have multiple writers.
+
+    Uses a Postgres sequence to coordinate ID assignment, but positions of other
+    writers will only get updated when `advance` is called (by replication).
+
+    Note: Only works with Postgres.
+
+    Args:
+        db_conn
+        db
+        instance_name: The name of this instance.
+        table: Database table associated with stream.
+        instance_column: Column that stores the row's writer's instance name
+        id_column: Column that stores the stream ID.
+        sequence_name: The name of the postgres sequence used to generate new
+            IDs.
+    """
+
+    def __init__(
+        self,
+        db_conn,
+        db: Database,
+        instance_name: str,
+        table: str,
+        instance_column: str,
+        id_column: str,
+        sequence_name: str,
+    ):
+        self._db = db
+        self._instance_name = instance_name
+        self._sequence_name = sequence_name
+
+        # We lock as some functions may be called from DB threads.
+        self._lock = threading.Lock()
+
+        self._current_positions = self._load_current_ids(
+            db_conn, table, instance_column, id_column
+        )
+
+        # Set of local IDs that we're still processing. The current position
+        # should be less than the minimum of this set (if not empty).
+        self._unfinished_ids = set()  # type: Set[int]
+
+    def _load_current_ids(
+        self, db_conn, table: str, instance_column: str, id_column: str
+    ) -> Dict[str, int]:
+        sql = """
+            SELECT %(instance)s, MAX(%(id)s) FROM %(table)s
+            GROUP BY %(instance)s
+        """ % {
+            "instance": instance_column,
+            "id": id_column,
+            "table": table,
+        }
+
+        cur = db_conn.cursor()
+        cur.execute(sql)
+
+        # `cur` is an iterable over returned rows, which are 2-tuples.
+        current_positions = dict(cur)
+
+        cur.close()
+
+        return current_positions
+
+    def _load_next_id_txn(self, txn):
+        txn.execute("SELECT nextval(?)", (self._sequence_name,))
+        (next_id,) = txn.fetchone()
+        return next_id
+
+    async def get_next(self):
+        """
+        Usage:
+            with await stream_id_gen.get_next() as stream_id:
+                # ... persist event ...
+        """
+        next_id = await self._db.runInteraction("_load_next_id", self._load_next_id_txn)
+
+        # Assert the fetched ID is actually greater than what we currently
+        # believe the ID to be. If not, then the sequence and table have got
+        # out of sync somehow.
+        assert self.get_current_token() < next_id
+
+        with self._lock:
+            self._unfinished_ids.add(next_id)
+
+        @contextlib.contextmanager
+        def manager():
+            try:
+                yield next_id
+            finally:
+                self._mark_id_as_finished(next_id)
+
+        return manager()
+
+    def get_next_txn(self, txn: LoggingTransaction):
+        """
+        Usage:
+
+            stream_id = stream_id_gen.get_next(txn)
+            # ... persist event ...
+        """
+
+        next_id = self._load_next_id_txn(txn)
+
+        with self._lock:
+            self._unfinished_ids.add(next_id)
+
+        txn.call_after(self._mark_id_as_finished, next_id)
+        txn.call_on_exception(self._mark_id_as_finished, next_id)
+
+        return next_id
+
+    def _mark_id_as_finished(self, next_id: int):
+        """The ID has finished being processed so we should advance the
+        current poistion if possible.
+        """
+
+        with self._lock:
+            self._unfinished_ids.discard(next_id)
+
+            # Figure out if its safe to advance the position by checking there
+            # aren't any lower allocated IDs that are yet to finish.
+            if all(c > next_id for c in self._unfinished_ids):
+                curr = self._current_positions.get(self._instance_name, 0)
+                self._current_positions[self._instance_name] = max(curr, next_id)
+
+    def get_current_token(self, instance_name: str = None) -> int:
+        """Gets the current position of a named writer (defaults to current
+        instance).
+
+        Returns 0 if we don't have a position for the named writer (likely due
+        to it being a new writer).
+        """
+
+        if instance_name is None:
+            instance_name = self._instance_name
+
+        with self._lock:
+            return self._current_positions.get(instance_name, 0)
+
+    def get_positions(self) -> Dict[str, int]:
+        """Get a copy of the current positon map.
+        """
+
+        with self._lock:
+            return dict(self._current_positions)
+
+    def advance(self, instance_name: str, new_id: int):
+        """Advance the postion of the named writer to the given ID, if greater
+        than existing entry.
+        """
+
+        with self._lock:
+            self._current_positions[instance_name] = max(
+                new_id, self._current_positions.get(instance_name, 0)
+            )
diff --git a/synapse/util/caches/__init__.py b/synapse/util/caches/__init__.py
index da5077b47105..dd356bf156da 100644
--- a/synapse/util/caches/__init__.py
+++ b/synapse/util/caches/__init__.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2015, 2016 OpenMarket Ltd
-# Copyright 2019 The Matrix.org Foundation C.I.C.
+# Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,28 +15,16 @@
 # limitations under the License.
 
 import logging
-import os
-from typing import Dict
+from sys import intern
+from typing import Callable, Dict, Optional
 
-import six
-from six.moves import intern
+import attr
+from prometheus_client.core import Gauge
 
-from prometheus_client.core import REGISTRY, Gauge, GaugeMetricFamily
+from synapse.config.cache import add_resizable_cache
 
 logger = logging.getLogger(__name__)
 
-CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.5))
-
-
-def get_cache_factor_for(cache_name):
-    env_var = "SYNAPSE_CACHE_FACTOR_" + cache_name.upper()
-    factor = os.environ.get(env_var)
-    if factor:
-        return float(factor)
-
-    return CACHE_SIZE_FACTOR
-
-
 caches_by_name = {}
 collectors_by_name = {}  # type: Dict
 
@@ -44,6 +32,7 @@ def get_cache_factor_for(cache_name):
 cache_hits = Gauge("synapse_util_caches_cache:hits", "", ["name"])
 cache_evicted = Gauge("synapse_util_caches_cache:evicted_size", "", ["name"])
 cache_total = Gauge("synapse_util_caches_cache:total", "", ["name"])
+cache_max_size = Gauge("synapse_util_caches_cache_max_size", "", ["name"])
 
 response_cache_size = Gauge("synapse_util_caches_response_cache:size", "", ["name"])
 response_cache_hits = Gauge("synapse_util_caches_response_cache:hits", "", ["name"])
@@ -53,67 +42,82 @@ def get_cache_factor_for(cache_name):
 response_cache_total = Gauge("synapse_util_caches_response_cache:total", "", ["name"])
 
 
-def register_cache(cache_type, cache_name, cache, collect_callback=None):
-    """Register a cache object for metric collection.
+@attr.s
+class CacheMetric(object):
+
+    _cache = attr.ib()
+    _cache_type = attr.ib(type=str)
+    _cache_name = attr.ib(type=str)
+    _collect_callback = attr.ib(type=Optional[Callable])
+
+    hits = attr.ib(default=0)
+    misses = attr.ib(default=0)
+    evicted_size = attr.ib(default=0)
+
+    def inc_hits(self):
+        self.hits += 1
+
+    def inc_misses(self):
+        self.misses += 1
+
+    def inc_evictions(self, size=1):
+        self.evicted_size += size
+
+    def describe(self):
+        return []
+
+    def collect(self):
+        try:
+            if self._cache_type == "response_cache":
+                response_cache_size.labels(self._cache_name).set(len(self._cache))
+                response_cache_hits.labels(self._cache_name).set(self.hits)
+                response_cache_evicted.labels(self._cache_name).set(self.evicted_size)
+                response_cache_total.labels(self._cache_name).set(
+                    self.hits + self.misses
+                )
+            else:
+                cache_size.labels(self._cache_name).set(len(self._cache))
+                cache_hits.labels(self._cache_name).set(self.hits)
+                cache_evicted.labels(self._cache_name).set(self.evicted_size)
+                cache_total.labels(self._cache_name).set(self.hits + self.misses)
+                if getattr(self._cache, "max_size", None):
+                    cache_max_size.labels(self._cache_name).set(self._cache.max_size)
+            if self._collect_callback:
+                self._collect_callback()
+        except Exception as e:
+            logger.warning("Error calculating metrics for %s: %s", self._cache_name, e)
+            raise
+
+
+def register_cache(
+    cache_type: str,
+    cache_name: str,
+    cache,
+    collect_callback: Optional[Callable] = None,
+    resizable: bool = True,
+    resize_callback: Optional[Callable] = None,
+) -> CacheMetric:
+    """Register a cache object for metric collection and resizing.
 
     Args:
-        cache_type (str):
-        cache_name (str): name of the cache
-        cache (object): cache itself
-        collect_callback (callable|None): if not None, a function which is called during
-            metric collection to update additional metrics.
+        cache_type
+        cache_name: name of the cache
+        cache: cache itself
+        collect_callback: If given, a function which is called during metric
+            collection to update additional metrics.
+        resizable: Whether this cache supports being resized.
+        resize_callback: A function which can be called to resize the cache.
 
     Returns:
         CacheMetric: an object which provides inc_{hits,misses,evictions} methods
     """
+    if resizable:
+        if not resize_callback:
+            resize_callback = getattr(cache, "set_cache_factor")
+        add_resizable_cache(cache_name, resize_callback)
 
-    # Check if the metric is already registered. Unregister it, if so.
-    # This usually happens during tests, as at runtime these caches are
-    # effectively singletons.
+    metric = CacheMetric(cache, cache_type, cache_name, collect_callback)
     metric_name = "cache_%s_%s" % (cache_type, cache_name)
-    if metric_name in collectors_by_name.keys():
-        REGISTRY.unregister(collectors_by_name[metric_name])
-
-    class CacheMetric(object):
-
-        hits = 0
-        misses = 0
-        evicted_size = 0
-
-        def inc_hits(self):
-            self.hits += 1
-
-        def inc_misses(self):
-            self.misses += 1
-
-        def inc_evictions(self, size=1):
-            self.evicted_size += size
-
-        def describe(self):
-            return []
-
-        def collect(self):
-            try:
-                if cache_type == "response_cache":
-                    response_cache_size.labels(cache_name).set(len(cache))
-                    response_cache_hits.labels(cache_name).set(self.hits)
-                    response_cache_evicted.labels(cache_name).set(self.evicted_size)
-                    response_cache_total.labels(cache_name).set(self.hits + self.misses)
-                else:
-                    cache_size.labels(cache_name).set(len(cache))
-                    cache_hits.labels(cache_name).set(self.hits)
-                    cache_evicted.labels(cache_name).set(self.evicted_size)
-                    cache_total.labels(cache_name).set(self.hits + self.misses)
-                if collect_callback:
-                    collect_callback()
-            except Exception as e:
-                logger.warning("Error calculating metrics for %s: %s", cache_name, e)
-                raise
-
-            yield GaugeMetricFamily("__unused", "")
-
-    metric = CacheMetric()
-    REGISTRY.register(metric)
     caches_by_name[cache_name] = cache
     collectors_by_name[metric_name] = metric
     return metric
@@ -148,9 +152,6 @@ def intern_string(string):
         return None
 
     try:
-        if six.PY2:
-            string = string.encode("ascii")
-
         return intern(string)
     except UnicodeEncodeError:
         return string
diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py
index 2e8f6543e5ae..cd4826242035 100644
--- a/synapse/util/caches/descriptors.py
+++ b/synapse/util/caches/descriptors.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 import functools
 import inspect
 import logging
@@ -30,7 +31,6 @@
 from synapse.logging.context import make_deferred_yieldable, preserve_fn
 from synapse.util import unwrapFirstError
 from synapse.util.async_helpers import ObservableDeferred
-from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.caches.treecache import TreeCache, iterate_tree_cache_entry
 
@@ -81,7 +81,6 @@ def invalidate(self):
 class Cache(object):
     __slots__ = (
         "cache",
-        "max_entries",
         "name",
         "keylen",
         "thread",
@@ -89,7 +88,29 @@ class Cache(object):
         "_pending_deferred_cache",
     )
 
-    def __init__(self, name, max_entries=1000, keylen=1, tree=False, iterable=False):
+    def __init__(
+        self,
+        name: str,
+        max_entries: int = 1000,
+        keylen: int = 1,
+        tree: bool = False,
+        iterable: bool = False,
+        apply_cache_factor_from_config: bool = True,
+    ):
+        """
+        Args:
+            name: The name of the cache
+            max_entries: Maximum amount of entries that the cache will hold
+            keylen: The length of the tuple used as the cache key
+            tree: Use a TreeCache instead of a dict as the underlying cache type
+            iterable: If True, count each item in the cached object as an entry,
+                rather than each cached object
+            apply_cache_factor_from_config: Whether cache factors specified in the
+                config file affect `max_entries`
+
+        Returns:
+            Cache
+        """
         cache_type = TreeCache if tree else dict
         self._pending_deferred_cache = cache_type()
 
@@ -99,6 +120,7 @@ def __init__(self, name, max_entries=1000, keylen=1, tree=False, iterable=False)
             cache_type=cache_type,
             size_callback=(lambda d: len(d)) if iterable else None,
             evicted_callback=self._on_evicted,
+            apply_cache_factor_from_config=apply_cache_factor_from_config,
         )
 
         self.name = name
@@ -111,6 +133,10 @@ def __init__(self, name, max_entries=1000, keylen=1, tree=False, iterable=False)
             collect_callback=self._metrics_collection_callback,
         )
 
+    @property
+    def max_entries(self):
+        return self.cache.max_size
+
     def _on_evicted(self, evicted_count):
         self.metrics.inc_evictions(evicted_count)
 
@@ -370,13 +396,11 @@ def __init__(
             cache_context=cache_context,
         )
 
-        max_entries = int(max_entries * get_cache_factor_for(orig.__name__))
-
         self.max_entries = max_entries
         self.tree = tree
         self.iterable = iterable
 
-    def __get__(self, obj, objtype=None):
+    def __get__(self, obj, owner):
         cache = Cache(
             name=self.orig.__name__,
             max_entries=self.max_entries,
diff --git a/synapse/util/caches/expiringcache.py b/synapse/util/caches/expiringcache.py
index cddf1ed51521..2726b67b6d5a 100644
--- a/synapse/util/caches/expiringcache.py
+++ b/synapse/util/caches/expiringcache.py
@@ -18,6 +18,7 @@
 
 from six import iteritems, itervalues
 
+from synapse.config import cache as cache_config
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.util.caches import register_cache
 
@@ -51,15 +52,16 @@ def __init__(
                 an item on access. Defaults to False.
             iterable (bool): If true, the size is calculated by summing the
                 sizes of all entries, rather than the number of entries.
-
         """
         self._cache_name = cache_name
 
+        self._original_max_size = max_len
+
+        self._max_size = int(max_len * cache_config.properties.default_factor_size)
+
         self._clock = clock
 
-        self._max_len = max_len
         self._expiry_ms = expiry_ms
-
         self._reset_expiry_on_get = reset_expiry_on_get
 
         self._cache = OrderedDict()
@@ -82,9 +84,11 @@ def f():
     def __setitem__(self, key, value):
         now = self._clock.time_msec()
         self._cache[key] = _CacheEntry(now, value)
+        self.evict()
 
+    def evict(self):
         # Evict if there are now too many items
-        while self._max_len and len(self) > self._max_len:
+        while self._max_size and len(self) > self._max_size:
             _key, value = self._cache.popitem(last=False)
             if self.iterable:
                 self.metrics.inc_evictions(len(value.value))
@@ -170,6 +174,23 @@ def __len__(self):
         else:
             return len(self._cache)
 
+    def set_cache_factor(self, factor: float) -> bool:
+        """
+        Set the cache factor for this individual cache.
+
+        This will trigger a resize if it changes, which may require evicting
+        items from the cache.
+
+        Returns:
+            bool: Whether the cache changed size or not.
+        """
+        new_size = int(self._original_max_size * factor)
+        if new_size != self._max_size:
+            self._max_size = new_size
+            self.evict()
+            return True
+        return False
+
 
 class _CacheEntry(object):
     __slots__ = ["time", "value"]
diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py
index 1536cb64f3bd..29fabac3cdb7 100644
--- a/synapse/util/caches/lrucache.py
+++ b/synapse/util/caches/lrucache.py
@@ -13,10 +13,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
 import threading
 from functools import wraps
+from typing import Callable, Optional, Type, Union
 
+from synapse.config import cache as cache_config
 from synapse.util.caches.treecache import TreeCache
 
 
@@ -52,17 +53,18 @@ class LruCache(object):
 
     def __init__(
         self,
-        max_size,
-        keylen=1,
-        cache_type=dict,
-        size_callback=None,
-        evicted_callback=None,
+        max_size: int,
+        keylen: int = 1,
+        cache_type: Type[Union[dict, TreeCache]] = dict,
+        size_callback: Optional[Callable] = None,
+        evicted_callback: Optional[Callable] = None,
+        apply_cache_factor_from_config: bool = True,
     ):
         """
         Args:
-            max_size (int):
+            max_size: The maximum amount of entries the cache can hold
 
-            keylen (int):
+            keylen: The length of the tuple used as the cache key
 
             cache_type (type):
                 type of underlying cache to be used. Typically one of dict
@@ -73,9 +75,23 @@ def __init__(
             evicted_callback (func(int)|None):
                 if not None, called on eviction with the size of the evicted
                 entry
+
+            apply_cache_factor_from_config (bool): If true, `max_size` will be
+                multiplied by a cache factor derived from the homeserver config
         """
         cache = cache_type()
         self.cache = cache  # Used for introspection.
+
+        # Save the original max size, and apply the default size factor.
+        self._original_max_size = max_size
+        # We previously didn't apply the cache factor here, and as such some caches were
+        # not affected by the global cache factor. Add an option here to disable applying
+        # the cache factor when a cache is created
+        if apply_cache_factor_from_config:
+            self.max_size = int(max_size * cache_config.properties.default_factor_size)
+        else:
+            self.max_size = int(max_size)
+
         list_root = _Node(None, None, None, None)
         list_root.next_node = list_root
         list_root.prev_node = list_root
@@ -83,7 +99,7 @@ def __init__(
         lock = threading.Lock()
 
         def evict():
-            while cache_len() > max_size:
+            while cache_len() > self.max_size:
                 todelete = list_root.prev_node
                 evicted_len = delete_node(todelete)
                 cache.pop(todelete.key, None)
@@ -236,6 +252,7 @@ def cache_contains(key):
             return key in cache
 
         self.sentinel = object()
+        self._on_resize = evict
         self.get = cache_get
         self.set = cache_set
         self.setdefault = cache_set_default
@@ -266,3 +283,20 @@ def __len__(self):
 
     def __contains__(self, key):
         return self.contains(key)
+
+    def set_cache_factor(self, factor: float) -> bool:
+        """
+        Set the cache factor for this individual cache.
+
+        This will trigger a resize if it changes, which may require evicting
+        items from the cache.
+
+        Returns:
+            bool: Whether the cache changed size or not.
+        """
+        new_size = int(self._original_max_size * factor)
+        if new_size != self.max_size:
+            self.max_size = new_size
+            self._on_resize()
+            return True
+        return False
diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py
index b68f9fe0d488..a6c60888e5f8 100644
--- a/synapse/util/caches/response_cache.py
+++ b/synapse/util/caches/response_cache.py
@@ -38,7 +38,7 @@ def __init__(self, hs, name, timeout_ms=0):
         self.timeout_sec = timeout_ms / 1000.0
 
         self._name = name
-        self._metrics = register_cache("response_cache", name, self)
+        self._metrics = register_cache("response_cache", name, self, resizable=False)
 
     def size(self):
         return len(self.pending_result_cache)
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py
index e54f80d76eeb..2a161bf24449 100644
--- a/synapse/util/caches/stream_change_cache.py
+++ b/synapse/util/caches/stream_change_cache.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import logging
+import math
 from typing import Dict, FrozenSet, List, Mapping, Optional, Set, Union
 
 from six import integer_types
@@ -46,7 +47,8 @@ def __init__(
         max_size=10000,
         prefilled_cache: Optional[Mapping[EntityType, int]] = None,
     ):
-        self._max_size = int(max_size * caches.CACHE_SIZE_FACTOR)
+        self._original_max_size = max_size
+        self._max_size = math.floor(max_size)
         self._entity_to_key = {}  # type: Dict[EntityType, int]
 
         # map from stream id to the a set of entities which changed at that stream id.
@@ -58,12 +60,31 @@ def __init__(
         #
         self._earliest_known_stream_pos = current_stream_pos
         self.name = name
-        self.metrics = caches.register_cache("cache", self.name, self._cache)
+        self.metrics = caches.register_cache(
+            "cache", self.name, self._cache, resize_callback=self.set_cache_factor
+        )
 
         if prefilled_cache:
             for entity, stream_pos in prefilled_cache.items():
                 self.entity_has_changed(entity, stream_pos)
 
+    def set_cache_factor(self, factor: float) -> bool:
+        """
+        Set the cache factor for this individual cache.
+
+        This will trigger a resize if it changes, which may require evicting
+        items from the cache.
+
+        Returns:
+            bool: Whether the cache changed size or not.
+        """
+        new_size = math.floor(self._original_max_size * factor)
+        if new_size != self._max_size:
+            self.max_size = new_size
+            self._evict()
+            return True
+        return False
+
     def has_entity_changed(self, entity: EntityType, stream_pos: int) -> bool:
         """Returns True if the entity may have been updated since stream_pos
         """
@@ -171,6 +192,7 @@ def entity_has_changed(self, entity: EntityType, stream_pos: int) -> None:
             e1 = self._cache[stream_pos] = set()
         e1.add(entity)
         self._entity_to_key[entity] = stream_pos
+        self._evict()
 
         # if the cache is too big, remove entries
         while len(self._cache) > self._max_size:
@@ -179,6 +201,13 @@ def entity_has_changed(self, entity: EntityType, stream_pos: int) -> None:
             for entity in r:
                 del self._entity_to_key[entity]
 
+    def _evict(self):
+        while len(self._cache) > self._max_size:
+            k, r = self._cache.popitem(0)
+            self._earliest_known_stream_pos = max(k, self._earliest_known_stream_pos)
+            for entity in r:
+                self._entity_to_key.pop(entity, None)
+
     def get_max_pos_of_last_change(self, entity: EntityType) -> int:
 
         """Returns an upper bound of the stream id of the last change to an
diff --git a/synapse/util/caches/ttlcache.py b/synapse/util/caches/ttlcache.py
index 99646c7cf09b..6437aa907e0f 100644
--- a/synapse/util/caches/ttlcache.py
+++ b/synapse/util/caches/ttlcache.py
@@ -38,7 +38,7 @@ def __init__(self, cache_name, timer=time.time):
 
         self._timer = timer
 
-        self._metrics = register_cache("ttl", cache_name, self)
+        self._metrics = register_cache("ttl", cache_name, self, resizable=False)
 
     def set(self, key, value, ttl):
         """Add/update an entry in the cache
diff --git a/synapse/util/frozenutils.py b/synapse/util/frozenutils.py
index f2ccd5e7c6bd..9815bb8667f4 100644
--- a/synapse/util/frozenutils.py
+++ b/synapse/util/frozenutils.py
@@ -65,5 +65,5 @@ def _handle_frozendict(obj):
     )
 
 
-# A JSONEncoder which is capable of encoding frozendics without barfing
+# A JSONEncoder which is capable of encoding frozendicts without barfing
 frozendict_json_encoder = json.JSONEncoder(default=_handle_frozendict)
diff --git a/synapse/util/stringutils.py b/synapse/util/stringutils.py
index 6899bcb788bf..08c86e92b86e 100644
--- a/synapse/util/stringutils.py
+++ b/synapse/util/stringutils.py
@@ -19,10 +19,6 @@
 import string
 from collections import Iterable
 
-import six
-from six import PY2, PY3
-from six.moves import range
-
 from synapse.api.errors import Codes, SynapseError
 
 _string_with_symbols = string.digits + string.ascii_letters + ".,;:^&*-_+=#~@"
@@ -47,80 +43,16 @@ def random_string_with_symbols(length):
 
 
 def is_ascii(s):
-
-    if PY3:
-        if isinstance(s, bytes):
-            try:
-                s.decode("ascii").encode("ascii")
-            except UnicodeDecodeError:
-                return False
-            except UnicodeEncodeError:
-                return False
-            return True
-
-    try:
-        s.encode("ascii")
-    except UnicodeEncodeError:
-        return False
-    except UnicodeDecodeError:
-        return False
-    else:
+    if isinstance(s, bytes):
+        try:
+            s.decode("ascii").encode("ascii")
+        except UnicodeDecodeError:
+            return False
+        except UnicodeEncodeError:
+            return False
         return True
 
 
-def to_ascii(s):
-    """Converts a string to ascii if it is ascii, otherwise leave it alone.
-
-    If given None then will return None.
-    """
-    if PY3:
-        return s
-
-    if s is None:
-        return None
-
-    try:
-        return s.encode("ascii")
-    except UnicodeEncodeError:
-        return s
-
-
-def exception_to_unicode(e):
-    """Helper function to extract the text of an exception as a unicode string
-
-    Args:
-        e (Exception): exception to be stringified
-
-    Returns:
-        unicode
-    """
-    # urgh, this is a mess. The basic problem here is that psycopg2 constructs its
-    # exceptions with PyErr_SetString, with a (possibly non-ascii) argument. str() will
-    # then produce the raw byte sequence. Under Python 2, this will then cause another
-    # error if it gets mixed with a `unicode` object, as per
-    # https://github.com/matrix-org/synapse/issues/4252
-
-    # First of all, if we're under python3, everything is fine because it will sort this
-    # nonsense out for us.
-    if not PY2:
-        return str(e)
-
-    # otherwise let's have a stab at decoding the exception message. We'll circumvent
-    # Exception.__str__(), which would explode if someone raised Exception(u'non-ascii')
-    # and instead look at what is in the args member.
-
-    if len(e.args) == 0:
-        return ""
-    elif len(e.args) > 1:
-        return six.text_type(repr(e.args))
-
-    msg = e.args[0]
-    if isinstance(msg, bytes):
-        return msg.decode("utf-8", errors="replace")
-    else:
-        return msg
-
-
 def assert_valid_client_secret(client_secret):
     """Validate that a given string matches the client_secret regex defined by the spec"""
     if client_secret_regex.match(client_secret) is None:
diff --git a/synctl b/synctl
index bbccd0529088..81e9bf6b5c39 100755
--- a/synctl
+++ b/synctl
@@ -142,12 +142,23 @@ def start_worker(app: str, configfile: str, worker_configfile: str) -> bool:
         return False
 
 
-def stop(pidfile, app):
+def stop(pidfile: str, app: str) -> bool:
+    """Attempts to kill a synapse worker from the pidfile.
+    Args:
+        pidfile: path to file containing worker's pid
+        app: name of the worker's appservice
+
+    Returns:
+        True if the process stopped successfully
+        False if process was already stopped or an error occured
+    """
+
     if os.path.exists(pidfile):
         pid = int(open(pidfile).read())
         try:
             os.kill(pid, signal.SIGTERM)
             write("stopped %s" % (app,), colour=GREEN)
+            return True
         except OSError as err:
             if err.errno == errno.ESRCH:
                 write("%s not running" % (app,), colour=YELLOW)
@@ -155,6 +166,14 @@ def stop(pidfile, app):
                 abort("Cannot stop %s: Operation not permitted" % (app,))
             else:
                 abort("Cannot stop %s: Unknown error" % (app,))
+            return False
+    else:
+        write(
+            "No running worker of %s found (from %s)\nThe process might be managed by another controller (e.g. systemd)"
+            % (app, pidfile),
+            colour=YELLOW,
+        )
+    return False
 
 
 Worker = collections.namedtuple(
@@ -300,11 +319,17 @@ def main():
     action = options.action
 
     if action == "stop" or action == "restart":
+        has_stopped = True
         for worker in workers:
-            stop(worker.pidfile, worker.app)
+            if not stop(worker.pidfile, worker.app):
+                # A worker could not be stopped.
+                has_stopped = False
 
         if start_stop_synapse:
-            stop(pidfile, "synapse.app.homeserver")
+            if not stop(pidfile, "synapse.app.homeserver"):
+                has_stopped = False
+        if not has_stopped:
+            sys.exit(1)
 
     # Wait for synapse to actually shutdown before starting it again
     if action == "restart":
diff --git a/tests/config/test_cache.py b/tests/config/test_cache.py
new file mode 100644
index 000000000000..292027912569
--- /dev/null
+++ b/tests/config/test_cache.py
@@ -0,0 +1,127 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from synapse.config._base import Config, RootConfig
+from synapse.config.cache import CacheConfig, add_resizable_cache
+from synapse.util.caches.lrucache import LruCache
+
+from tests.unittest import TestCase
+
+
+class FakeServer(Config):
+    section = "server"
+
+
+class TestConfig(RootConfig):
+    config_classes = [FakeServer, CacheConfig]
+
+
+class CacheConfigTests(TestCase):
+    def setUp(self):
+        # Reset caches before each test
+        TestConfig().caches.reset()
+
+    def test_individual_caches_from_environ(self):
+        """
+        Individual cache factors will be loaded from the environment.
+        """
+        config = {}
+        t = TestConfig()
+        t.caches._environ = {
+            "SYNAPSE_CACHE_FACTOR_SOMETHING_OR_OTHER": "2",
+            "SYNAPSE_NOT_CACHE": "BLAH",
+        }
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(dict(t.caches.cache_factors), {"something_or_other": 2.0})
+
+    def test_config_overrides_environ(self):
+        """
+        Individual cache factors defined in the environment will take precedence
+        over those in the config.
+        """
+        config = {"caches": {"per_cache_factors": {"foo": 2, "bar": 3}}}
+        t = TestConfig()
+        t.caches._environ = {
+            "SYNAPSE_CACHE_FACTOR_SOMETHING_OR_OTHER": "2",
+            "SYNAPSE_CACHE_FACTOR_FOO": 1,
+        }
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(
+            dict(t.caches.cache_factors),
+            {"foo": 1.0, "bar": 3.0, "something_or_other": 2.0},
+        )
+
+    def test_individual_instantiated_before_config_load(self):
+        """
+        If a cache is instantiated before the config is read, it will be given
+        the default cache size in the interim, and then resized once the config
+        is loaded.
+        """
+        cache = LruCache(100)
+
+        add_resizable_cache("foo", cache_resize_callback=cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 50)
+
+        config = {"caches": {"per_cache_factors": {"foo": 3}}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(cache.max_size, 300)
+
+    def test_individual_instantiated_after_config_load(self):
+        """
+        If a cache is instantiated after the config is read, it will be
+        immediately resized to the correct size given the per_cache_factor if
+        there is one.
+        """
+        config = {"caches": {"per_cache_factors": {"foo": 2}}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache_resize_callback=cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 200)
+
+    def test_global_instantiated_before_config_load(self):
+        """
+        If a cache is instantiated before the config is read, it will be given
+        the default cache size in the interim, and then resized to the new
+        default cache size once the config is loaded.
+        """
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache_resize_callback=cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 50)
+
+        config = {"caches": {"global_factor": 4}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(cache.max_size, 400)
+
+    def test_global_instantiated_after_config_load(self):
+        """
+        If a cache is instantiated after the config is read, it will be
+        immediately resized to the correct size given the global factor if there
+        is no per-cache factor.
+        """
+        config = {"caches": {"global_factor": 1.5}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache_resize_callback=cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 150)
diff --git a/tests/events/test_utils.py b/tests/events/test_utils.py
index ab5f5ac54963..c1274c14af59 100644
--- a/tests/events/test_utils.py
+++ b/tests/events/test_utils.py
@@ -156,7 +156,7 @@ def test_msc2432_alias_event(self):
                 "signatures": {},
                 "unsigned": {},
             },
-            room_version=RoomVersions.MSC2432_DEV,
+            room_version=RoomVersions.V6,
         )
 
 
diff --git a/tests/handlers/test_federation.py b/tests/handlers/test_federation.py
index 132e35651dbb..96fea5867309 100644
--- a/tests/handlers/test_federation.py
+++ b/tests/handlers/test_federation.py
@@ -13,9 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+from unittest import TestCase
 
 from synapse.api.constants import EventTypes
-from synapse.api.errors import AuthError, Codes
+from synapse.api.errors import AuthError, Codes, SynapseError
+from synapse.api.room_versions import RoomVersions
+from synapse.events import EventBase
 from synapse.federation.federation_base import event_from_pdu_json
 from synapse.logging.context import LoggingContext, run_in_background
 from synapse.rest import admin
@@ -207,3 +210,65 @@ def _build_and_send_join_event(self, other_server, other_user, room_id):
         self.assertEqual(r[(EventTypes.Member, other_user)], join_event.event_id)
 
         return join_event
+
+
+class EventFromPduTestCase(TestCase):
+    def test_valid_json(self):
+        """Valid JSON should be turned into an event."""
+        ev = event_from_pdu_json(
+            {
+                "type": EventTypes.Message,
+                "content": {"bool": True, "null": None, "int": 1, "str": "foobar"},
+                "room_id": "!room:test",
+                "sender": "@user:test",
+                "depth": 1,
+                "prev_events": [],
+                "auth_events": [],
+                "origin_server_ts": 1234,
+            },
+            RoomVersions.V6,
+        )
+
+        self.assertIsInstance(ev, EventBase)
+
+    def test_invalid_numbers(self):
+        """Invalid values for an integer should be rejected, all floats should be rejected."""
+        for value in [
+            -(2 ** 53),
+            2 ** 53,
+            1.0,
+            float("inf"),
+            float("-inf"),
+            float("nan"),
+        ]:
+            with self.assertRaises(SynapseError):
+                event_from_pdu_json(
+                    {
+                        "type": EventTypes.Message,
+                        "content": {"foo": value},
+                        "room_id": "!room:test",
+                        "sender": "@user:test",
+                        "depth": 1,
+                        "prev_events": [],
+                        "auth_events": [],
+                        "origin_server_ts": 1234,
+                    },
+                    RoomVersions.V6,
+                )
+
+    def test_invalid_nested(self):
+        """List and dictionaries are recursively searched."""
+        with self.assertRaises(SynapseError):
+            event_from_pdu_json(
+                {
+                    "type": EventTypes.Message,
+                    "content": {"foo": [{"bar": 2 ** 56}]},
+                    "room_id": "!room:test",
+                    "sender": "@user:test",
+                    "depth": 1,
+                    "prev_events": [],
+                    "auth_events": [],
+                    "origin_server_ts": 1234,
+                },
+                RoomVersions.V6,
+            )
diff --git a/tests/handlers/test_oidc.py b/tests/handlers/test_oidc.py
new file mode 100644
index 000000000000..1bb25ab6842c
--- /dev/null
+++ b/tests/handlers/test_oidc.py
@@ -0,0 +1,570 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Quentin Gliech
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json
+from urllib.parse import parse_qs, urlparse
+
+from mock import Mock, patch
+
+import attr
+import pymacaroons
+
+from twisted.internet import defer
+from twisted.python.failure import Failure
+from twisted.web._newclient import ResponseDone
+
+from synapse.handlers.oidc_handler import (
+    MappingException,
+    OidcError,
+    OidcHandler,
+    OidcMappingProvider,
+)
+from synapse.types import UserID
+
+from tests.unittest import HomeserverTestCase, override_config
+
+
+@attr.s
+class FakeResponse:
+    code = attr.ib()
+    body = attr.ib()
+    phrase = attr.ib()
+
+    def deliverBody(self, protocol):
+        protocol.dataReceived(self.body)
+        protocol.connectionLost(Failure(ResponseDone()))
+
+
+# These are a few constants that are used as config parameters in the tests.
+ISSUER = "https://issuer/"
+CLIENT_ID = "test-client-id"
+CLIENT_SECRET = "test-client-secret"
+BASE_URL = "https://synapse/"
+CALLBACK_URL = BASE_URL + "_synapse/oidc/callback"
+SCOPES = ["openid"]
+
+AUTHORIZATION_ENDPOINT = ISSUER + "authorize"
+TOKEN_ENDPOINT = ISSUER + "token"
+USERINFO_ENDPOINT = ISSUER + "userinfo"
+WELL_KNOWN = ISSUER + ".well-known/openid-configuration"
+JWKS_URI = ISSUER + ".well-known/jwks.json"
+
+# config for common cases
+COMMON_CONFIG = {
+    "discover": False,
+    "authorization_endpoint": AUTHORIZATION_ENDPOINT,
+    "token_endpoint": TOKEN_ENDPOINT,
+    "jwks_uri": JWKS_URI,
+}
+
+
+# The cookie name and path don't really matter, just that it has to be coherent
+# between the callback & redirect handlers.
+COOKIE_NAME = b"oidc_session"
+COOKIE_PATH = "/_synapse/oidc"
+
+MockedMappingProvider = Mock(OidcMappingProvider)
+
+
+def simple_async_mock(return_value=None, raises=None):
+    # AsyncMock is not available in python3.5, this mimics part of its behaviour
+    async def cb(*args, **kwargs):
+        if raises:
+            raise raises
+        return return_value
+
+    return Mock(side_effect=cb)
+
+
+async def get_json(url):
+    # Mock get_json calls to handle jwks & oidc discovery endpoints
+    if url == WELL_KNOWN:
+        # Minimal discovery document, as defined in OpenID.Discovery
+        # https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
+        return {
+            "issuer": ISSUER,
+            "authorization_endpoint": AUTHORIZATION_ENDPOINT,
+            "token_endpoint": TOKEN_ENDPOINT,
+            "jwks_uri": JWKS_URI,
+            "userinfo_endpoint": USERINFO_ENDPOINT,
+            "response_types_supported": ["code"],
+            "subject_types_supported": ["public"],
+            "id_token_signing_alg_values_supported": ["RS256"],
+        }
+    elif url == JWKS_URI:
+        return {"keys": []}
+
+
+class OidcHandlerTestCase(HomeserverTestCase):
+    def make_homeserver(self, reactor, clock):
+
+        self.http_client = Mock(spec=["get_json"])
+        self.http_client.get_json.side_effect = get_json
+        self.http_client.user_agent = "Synapse Test"
+
+        config = self.default_config()
+        config["public_baseurl"] = BASE_URL
+        oidc_config = config.get("oidc_config", {})
+        oidc_config["enabled"] = True
+        oidc_config["client_id"] = CLIENT_ID
+        oidc_config["client_secret"] = CLIENT_SECRET
+        oidc_config["issuer"] = ISSUER
+        oidc_config["scopes"] = SCOPES
+        oidc_config["user_mapping_provider"] = {
+            "module": __name__ + ".MockedMappingProvider"
+        }
+        config["oidc_config"] = oidc_config
+
+        hs = self.setup_test_homeserver(
+            http_client=self.http_client,
+            proxied_http_client=self.http_client,
+            config=config,
+        )
+
+        self.handler = OidcHandler(hs)
+
+        return hs
+
+    def metadata_edit(self, values):
+        return patch.dict(self.handler._provider_metadata, values)
+
+    def assertRenderedError(self, error, error_description=None):
+        args = self.handler._render_error.call_args[0]
+        self.assertEqual(args[1], error)
+        if error_description is not None:
+            self.assertEqual(args[2], error_description)
+        # Reset the render_error mock
+        self.handler._render_error.reset_mock()
+
+    def test_config(self):
+        """Basic config correctly sets up the callback URL and client auth correctly."""
+        self.assertEqual(self.handler._callback_url, CALLBACK_URL)
+        self.assertEqual(self.handler._client_auth.client_id, CLIENT_ID)
+        self.assertEqual(self.handler._client_auth.client_secret, CLIENT_SECRET)
+
+    @override_config({"oidc_config": {"discover": True}})
+    @defer.inlineCallbacks
+    def test_discovery(self):
+        """The handler should discover the endpoints from OIDC discovery document."""
+        # This would throw if some metadata were invalid
+        metadata = yield defer.ensureDeferred(self.handler.load_metadata())
+        self.http_client.get_json.assert_called_once_with(WELL_KNOWN)
+
+        self.assertEqual(metadata.issuer, ISSUER)
+        self.assertEqual(metadata.authorization_endpoint, AUTHORIZATION_ENDPOINT)
+        self.assertEqual(metadata.token_endpoint, TOKEN_ENDPOINT)
+        self.assertEqual(metadata.jwks_uri, JWKS_URI)
+        # FIXME: it seems like authlib does not have that defined in its metadata models
+        # self.assertEqual(metadata.userinfo_endpoint, USERINFO_ENDPOINT)
+
+        # subsequent calls should be cached
+        self.http_client.reset_mock()
+        yield defer.ensureDeferred(self.handler.load_metadata())
+        self.http_client.get_json.assert_not_called()
+
+    @override_config({"oidc_config": COMMON_CONFIG})
+    @defer.inlineCallbacks
+    def test_no_discovery(self):
+        """When discovery is disabled, it should not try to load from discovery document."""
+        yield defer.ensureDeferred(self.handler.load_metadata())
+        self.http_client.get_json.assert_not_called()
+
+    @override_config({"oidc_config": COMMON_CONFIG})
+    @defer.inlineCallbacks
+    def test_load_jwks(self):
+        """JWKS loading is done once (then cached) if used."""
+        jwks = yield defer.ensureDeferred(self.handler.load_jwks())
+        self.http_client.get_json.assert_called_once_with(JWKS_URI)
+        self.assertEqual(jwks, {"keys": []})
+
+        # subsequent calls should be cached…
+        self.http_client.reset_mock()
+        yield defer.ensureDeferred(self.handler.load_jwks())
+        self.http_client.get_json.assert_not_called()
+
+        # …unless forced
+        self.http_client.reset_mock()
+        yield defer.ensureDeferred(self.handler.load_jwks(force=True))
+        self.http_client.get_json.assert_called_once_with(JWKS_URI)
+
+        # Throw if the JWKS uri is missing
+        with self.metadata_edit({"jwks_uri": None}):
+            with self.assertRaises(RuntimeError):
+                yield defer.ensureDeferred(self.handler.load_jwks(force=True))
+
+        # Return empty key set if JWKS are not used
+        self.handler._scopes = []  # not asking the openid scope
+        self.http_client.get_json.reset_mock()
+        jwks = yield defer.ensureDeferred(self.handler.load_jwks(force=True))
+        self.http_client.get_json.assert_not_called()
+        self.assertEqual(jwks, {"keys": []})
+
+    @override_config({"oidc_config": COMMON_CONFIG})
+    def test_validate_config(self):
+        """Provider metadatas are extensively validated."""
+        h = self.handler
+
+        # Default test config does not throw
+        h._validate_metadata()
+
+        with self.metadata_edit({"issuer": None}):
+            self.assertRaisesRegex(ValueError, "issuer", h._validate_metadata)
+
+        with self.metadata_edit({"issuer": "http://insecure/"}):
+            self.assertRaisesRegex(ValueError, "issuer", h._validate_metadata)
+
+        with self.metadata_edit({"issuer": "https://invalid/?because=query"}):
+            self.assertRaisesRegex(ValueError, "issuer", h._validate_metadata)
+
+        with self.metadata_edit({"authorization_endpoint": None}):
+            self.assertRaisesRegex(
+                ValueError, "authorization_endpoint", h._validate_metadata
+            )
+
+        with self.metadata_edit({"authorization_endpoint": "http://insecure/auth"}):
+            self.assertRaisesRegex(
+                ValueError, "authorization_endpoint", h._validate_metadata
+            )
+
+        with self.metadata_edit({"token_endpoint": None}):
+            self.assertRaisesRegex(ValueError, "token_endpoint", h._validate_metadata)
+
+        with self.metadata_edit({"token_endpoint": "http://insecure/token"}):
+            self.assertRaisesRegex(ValueError, "token_endpoint", h._validate_metadata)
+
+        with self.metadata_edit({"jwks_uri": None}):
+            self.assertRaisesRegex(ValueError, "jwks_uri", h._validate_metadata)
+
+        with self.metadata_edit({"jwks_uri": "http://insecure/jwks.json"}):
+            self.assertRaisesRegex(ValueError, "jwks_uri", h._validate_metadata)
+
+        with self.metadata_edit({"response_types_supported": ["id_token"]}):
+            self.assertRaisesRegex(
+                ValueError, "response_types_supported", h._validate_metadata
+            )
+
+        with self.metadata_edit(
+            {"token_endpoint_auth_methods_supported": ["client_secret_basic"]}
+        ):
+            # should not throw, as client_secret_basic is the default auth method
+            h._validate_metadata()
+
+        with self.metadata_edit(
+            {"token_endpoint_auth_methods_supported": ["client_secret_post"]}
+        ):
+            self.assertRaisesRegex(
+                ValueError,
+                "token_endpoint_auth_methods_supported",
+                h._validate_metadata,
+            )
+
+        # Tests for configs that the userinfo endpoint
+        self.assertFalse(h._uses_userinfo)
+        h._scopes = []  # do not request the openid scope
+        self.assertTrue(h._uses_userinfo)
+        self.assertRaisesRegex(ValueError, "userinfo_endpoint", h._validate_metadata)
+
+        with self.metadata_edit(
+            {"userinfo_endpoint": USERINFO_ENDPOINT, "jwks_uri": None}
+        ):
+            # Shouldn't raise with a valid userinfo, even without
+            h._validate_metadata()
+
+    @override_config({"oidc_config": {"skip_verification": True}})
+    def test_skip_verification(self):
+        """Provider metadata validation can be disabled by config."""
+        with self.metadata_edit({"issuer": "http://insecure"}):
+            # This should not throw
+            self.handler._validate_metadata()
+
+    @defer.inlineCallbacks
+    def test_redirect_request(self):
+        """The redirect request has the right arguments & generates a valid session cookie."""
+        req = Mock(spec=["addCookie"])
+        url = yield defer.ensureDeferred(
+            self.handler.handle_redirect_request(req, b"http://client/redirect")
+        )
+        url = urlparse(url)
+        auth_endpoint = urlparse(AUTHORIZATION_ENDPOINT)
+
+        self.assertEqual(url.scheme, auth_endpoint.scheme)
+        self.assertEqual(url.netloc, auth_endpoint.netloc)
+        self.assertEqual(url.path, auth_endpoint.path)
+
+        params = parse_qs(url.query)
+        self.assertEqual(params["redirect_uri"], [CALLBACK_URL])
+        self.assertEqual(params["response_type"], ["code"])
+        self.assertEqual(params["scope"], [" ".join(SCOPES)])
+        self.assertEqual(params["client_id"], [CLIENT_ID])
+        self.assertEqual(len(params["state"]), 1)
+        self.assertEqual(len(params["nonce"]), 1)
+
+        # Check what is in the cookie
+        # note: python3.5 mock does not have the .called_once() method
+        calls = req.addCookie.call_args_list
+        self.assertEqual(len(calls), 1)  # called once
+        # For some reason, call.args does not work with python3.5
+        args = calls[0][0]
+        kwargs = calls[0][1]
+        self.assertEqual(args[0], COOKIE_NAME)
+        self.assertEqual(kwargs["path"], COOKIE_PATH)
+        cookie = args[1]
+
+        macaroon = pymacaroons.Macaroon.deserialize(cookie)
+        state = self.handler._get_value_from_macaroon(macaroon, "state")
+        nonce = self.handler._get_value_from_macaroon(macaroon, "nonce")
+        redirect = self.handler._get_value_from_macaroon(
+            macaroon, "client_redirect_url"
+        )
+
+        self.assertEqual(params["state"], [state])
+        self.assertEqual(params["nonce"], [nonce])
+        self.assertEqual(redirect, "http://client/redirect")
+
+    @defer.inlineCallbacks
+    def test_callback_error(self):
+        """Errors from the provider returned in the callback are displayed."""
+        self.handler._render_error = Mock()
+        request = Mock(args={})
+        request.args[b"error"] = [b"invalid_client"]
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_client", "")
+
+        request.args[b"error_description"] = [b"some description"]
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_client", "some description")
+
+    @defer.inlineCallbacks
+    def test_callback(self):
+        """Code callback works and display errors if something went wrong.
+
+        A lot of scenarios are tested here:
+         - when the callback works, with userinfo from ID token
+         - when the user mapping fails
+         - when ID token verification fails
+         - when the callback works, with userinfo fetched from the userinfo endpoint
+         - when the userinfo fetching fails
+         - when the code exchange fails
+        """
+        token = {
+            "type": "bearer",
+            "id_token": "id_token",
+            "access_token": "access_token",
+        }
+        userinfo = {
+            "sub": "foo",
+            "preferred_username": "bar",
+        }
+        user_id = UserID("foo", "domain.org")
+        self.handler._render_error = Mock(return_value=None)
+        self.handler._exchange_code = simple_async_mock(return_value=token)
+        self.handler._parse_id_token = simple_async_mock(return_value=userinfo)
+        self.handler._fetch_userinfo = simple_async_mock(return_value=userinfo)
+        self.handler._map_userinfo_to_user = simple_async_mock(return_value=user_id)
+        self.handler._auth_handler.complete_sso_login = simple_async_mock()
+        request = Mock(spec=["args", "getCookie", "addCookie"])
+
+        code = "code"
+        state = "state"
+        nonce = "nonce"
+        client_redirect_url = "http://client/redirect"
+        session = self.handler._generate_oidc_session_token(
+            state=state,
+            nonce=nonce,
+            client_redirect_url=client_redirect_url,
+            ui_auth_session_id=None,
+        )
+        request.getCookie.return_value = session
+
+        request.args = {}
+        request.args[b"code"] = [code.encode("utf-8")]
+        request.args[b"state"] = [state.encode("utf-8")]
+
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+
+        self.handler._auth_handler.complete_sso_login.assert_called_once_with(
+            user_id, request, client_redirect_url,
+        )
+        self.handler._exchange_code.assert_called_once_with(code)
+        self.handler._parse_id_token.assert_called_once_with(token, nonce=nonce)
+        self.handler._map_userinfo_to_user.assert_called_once_with(userinfo, token)
+        self.handler._fetch_userinfo.assert_not_called()
+        self.handler._render_error.assert_not_called()
+
+        # Handle mapping errors
+        self.handler._map_userinfo_to_user = simple_async_mock(
+            raises=MappingException()
+        )
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("mapping_error")
+        self.handler._map_userinfo_to_user = simple_async_mock(return_value=user_id)
+
+        # Handle ID token errors
+        self.handler._parse_id_token = simple_async_mock(raises=Exception())
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_token")
+
+        self.handler._auth_handler.complete_sso_login.reset_mock()
+        self.handler._exchange_code.reset_mock()
+        self.handler._parse_id_token.reset_mock()
+        self.handler._map_userinfo_to_user.reset_mock()
+        self.handler._fetch_userinfo.reset_mock()
+
+        # With userinfo fetching
+        self.handler._scopes = []  # do not ask the "openid" scope
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+
+        self.handler._auth_handler.complete_sso_login.assert_called_once_with(
+            user_id, request, client_redirect_url,
+        )
+        self.handler._exchange_code.assert_called_once_with(code)
+        self.handler._parse_id_token.assert_not_called()
+        self.handler._map_userinfo_to_user.assert_called_once_with(userinfo, token)
+        self.handler._fetch_userinfo.assert_called_once_with(token)
+        self.handler._render_error.assert_not_called()
+
+        # Handle userinfo fetching error
+        self.handler._fetch_userinfo = simple_async_mock(raises=Exception())
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("fetch_error")
+
+        # Handle code exchange failure
+        self.handler._exchange_code = simple_async_mock(
+            raises=OidcError("invalid_request")
+        )
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_request")
+
+    @defer.inlineCallbacks
+    def test_callback_session(self):
+        """The callback verifies the session presence and validity"""
+        self.handler._render_error = Mock(return_value=None)
+        request = Mock(spec=["args", "getCookie", "addCookie"])
+
+        # Missing cookie
+        request.args = {}
+        request.getCookie.return_value = None
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("missing_session", "No session cookie found")
+
+        # Missing session parameter
+        request.args = {}
+        request.getCookie.return_value = "session"
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_request", "State parameter is missing")
+
+        # Invalid cookie
+        request.args = {}
+        request.args[b"state"] = [b"state"]
+        request.getCookie.return_value = "session"
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_session")
+
+        # Mismatching session
+        session = self.handler._generate_oidc_session_token(
+            state="state",
+            nonce="nonce",
+            client_redirect_url="http://client/redirect",
+            ui_auth_session_id=None,
+        )
+        request.args = {}
+        request.args[b"state"] = [b"mismatching state"]
+        request.getCookie.return_value = session
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("mismatching_session")
+
+        # Valid session
+        request.args = {}
+        request.args[b"state"] = [b"state"]
+        request.getCookie.return_value = session
+        yield defer.ensureDeferred(self.handler.handle_oidc_callback(request))
+        self.assertRenderedError("invalid_request")
+
+    @override_config({"oidc_config": {"client_auth_method": "client_secret_post"}})
+    @defer.inlineCallbacks
+    def test_exchange_code(self):
+        """Code exchange behaves correctly and handles various error scenarios."""
+        token = {"type": "bearer"}
+        token_json = json.dumps(token).encode("utf-8")
+        self.http_client.request = simple_async_mock(
+            return_value=FakeResponse(code=200, phrase=b"OK", body=token_json)
+        )
+        code = "code"
+        ret = yield defer.ensureDeferred(self.handler._exchange_code(code))
+        kwargs = self.http_client.request.call_args[1]
+
+        self.assertEqual(ret, token)
+        self.assertEqual(kwargs["method"], "POST")
+        self.assertEqual(kwargs["uri"], TOKEN_ENDPOINT)
+
+        args = parse_qs(kwargs["data"].decode("utf-8"))
+        self.assertEqual(args["grant_type"], ["authorization_code"])
+        self.assertEqual(args["code"], [code])
+        self.assertEqual(args["client_id"], [CLIENT_ID])
+        self.assertEqual(args["client_secret"], [CLIENT_SECRET])
+        self.assertEqual(args["redirect_uri"], [CALLBACK_URL])
+
+        # Test error handling
+        self.http_client.request = simple_async_mock(
+            return_value=FakeResponse(
+                code=400,
+                phrase=b"Bad Request",
+                body=b'{"error": "foo", "error_description": "bar"}',
+            )
+        )
+        with self.assertRaises(OidcError) as exc:
+            yield defer.ensureDeferred(self.handler._exchange_code(code))
+        self.assertEqual(exc.exception.error, "foo")
+        self.assertEqual(exc.exception.error_description, "bar")
+
+        # Internal server error with no JSON body
+        self.http_client.request = simple_async_mock(
+            return_value=FakeResponse(
+                code=500, phrase=b"Internal Server Error", body=b"Not JSON",
+            )
+        )
+        with self.assertRaises(OidcError) as exc:
+            yield defer.ensureDeferred(self.handler._exchange_code(code))
+        self.assertEqual(exc.exception.error, "server_error")
+
+        # Internal server error with JSON body
+        self.http_client.request = simple_async_mock(
+            return_value=FakeResponse(
+                code=500,
+                phrase=b"Internal Server Error",
+                body=b'{"error": "internal_server_error"}',
+            )
+        )
+        with self.assertRaises(OidcError) as exc:
+            yield defer.ensureDeferred(self.handler._exchange_code(code))
+        self.assertEqual(exc.exception.error, "internal_server_error")
+
+        # 4xx error without "error" field
+        self.http_client.request = simple_async_mock(
+            return_value=FakeResponse(code=400, phrase=b"Bad request", body=b"{}",)
+        )
+        with self.assertRaises(OidcError) as exc:
+            yield defer.ensureDeferred(self.handler._exchange_code(code))
+        self.assertEqual(exc.exception.error, "server_error")
+
+        # 2xx error with "error" field
+        self.http_client.request = simple_async_mock(
+            return_value=FakeResponse(
+                code=200, phrase=b"OK", body=b'{"error": "some_error"}',
+            )
+        )
+        with self.assertRaises(OidcError) as exc:
+            yield defer.ensureDeferred(self.handler._exchange_code(code))
+        self.assertEqual(exc.exception.error, "some_error")
diff --git a/tests/handlers/test_user_directory.py b/tests/handlers/test_user_directory.py
index 7b92bdbc4767..572df8d80bf2 100644
--- a/tests/handlers/test_user_directory.py
+++ b/tests/handlers/test_user_directory.py
@@ -185,7 +185,7 @@ def check_username_for_spam(self, user_profile):
                 # Allow all users.
                 return False
 
-        spam_checker.spam_checker = AllowAll()
+        spam_checker.spam_checkers = [AllowAll()]
 
         # The results do not change:
         # We get one search result when searching for user2 by user1.
@@ -198,7 +198,7 @@ def check_username_for_spam(self, user_profile):
                 # All users are spammy.
                 return True
 
-        spam_checker.spam_checker = BlockAll()
+        spam_checker.spam_checkers = [BlockAll()]
 
         # User1 now gets no search results for any of the other users.
         s = self.get_success(self.handler.search_users(u1, "user2", 10))
diff --git a/tests/replication/tcp/streams/_base.py b/tests/replication/_base.py
similarity index 97%
rename from tests/replication/tcp/streams/_base.py
rename to tests/replication/_base.py
index 7b56d2028d94..9d4f0bbe44fd 100644
--- a/tests/replication/tcp/streams/_base.py
+++ b/tests/replication/_base.py
@@ -27,6 +27,7 @@
     GenericWorkerServer,
 )
 from synapse.http.site import SynapseRequest
+from synapse.replication.http import streams
 from synapse.replication.tcp.handler import ReplicationCommandHandler
 from synapse.replication.tcp.protocol import ClientReplicationStreamProtocol
 from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
@@ -42,6 +43,10 @@
 class BaseStreamTestCase(unittest.HomeserverTestCase):
     """Base class for tests of the replication streams"""
 
+    servlets = [
+        streams.register_servlets,
+    ]
+
     def prepare(self, reactor, clock, hs):
         # build a replication server
         server_factory = ReplicationStreamProtocolFactory(hs)
@@ -49,17 +54,11 @@ def prepare(self, reactor, clock, hs):
         self.server = server_factory.buildProtocol(None)
 
         # Make a new HomeServer object for the worker
-        config = self.default_config()
-        config["worker_app"] = "synapse.app.generic_worker"
-        config["worker_replication_host"] = "testserv"
-        config["worker_replication_http_port"] = "8765"
-
         self.reactor.lookups["testserv"] = "1.2.3.4"
-
         self.worker_hs = self.setup_test_homeserver(
             http_client=None,
             homeserverToUse=GenericWorkerServer,
-            config=config,
+            config=self._get_worker_hs_config(),
             reactor=self.reactor,
         )
 
@@ -78,6 +77,13 @@ def prepare(self, reactor, clock, hs):
         self._client_transport = None
         self._server_transport = None
 
+    def _get_worker_hs_config(self) -> dict:
+        config = self.default_config()
+        config["worker_app"] = "synapse.app.generic_worker"
+        config["worker_replication_host"] = "testserv"
+        config["worker_replication_http_port"] = "8765"
+        return config
+
     def _build_replication_data_handler(self):
         return TestReplicationDataHandler(self.worker_hs)
 
diff --git a/tests/replication/slave/storage/_base.py b/tests/replication/slave/storage/_base.py
index 1615dfab5e85..32cb04645f91 100644
--- a/tests/replication/slave/storage/_base.py
+++ b/tests/replication/slave/storage/_base.py
@@ -15,23 +15,13 @@
 
 from mock import Mock, NonCallableMock
 
-from synapse.replication.tcp.client import (
-    DirectTcpReplicationClientFactory,
-    ReplicationDataHandler,
-)
-from synapse.replication.tcp.handler import ReplicationCommandHandler
-from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
-from synapse.storage.database import make_conn
+from tests.replication._base import BaseStreamTestCase
 
-from tests import unittest
-from tests.server import FakeTransport
 
-
-class BaseSlavedStoreTestCase(unittest.HomeserverTestCase):
+class BaseSlavedStoreTestCase(BaseStreamTestCase):
     def make_homeserver(self, reactor, clock):
 
         hs = self.setup_test_homeserver(
-            "blue",
             federation_client=Mock(),
             ratelimiter=NonCallableMock(spec_set=["can_do_action"]),
         )
@@ -41,39 +31,13 @@ def make_homeserver(self, reactor, clock):
         return hs
 
     def prepare(self, reactor, clock, hs):
+        super().prepare(reactor, clock, hs)
 
-        db_config = hs.config.database.get_single_database()
-        self.master_store = self.hs.get_datastore()
-        self.storage = hs.get_storage()
-        database = hs.get_datastores().databases[0]
-        self.slaved_store = self.STORE_TYPE(
-            database, make_conn(db_config, database.engine), self.hs
-        )
-        self.event_id = 0
-
-        server_factory = ReplicationStreamProtocolFactory(self.hs)
-        self.streamer = hs.get_replication_streamer()
-
-        # We now do some gut wrenching so that we have a client that is based
-        # off of the slave store rather than the main store.
-        self.replication_handler = ReplicationCommandHandler(self.hs)
-        self.replication_handler._instance_name = "worker"
-        self.replication_handler._replication_data_handler = ReplicationDataHandler(
-            self.slaved_store
-        )
+        self.reconnect()
 
-        client_factory = DirectTcpReplicationClientFactory(
-            self.hs, "client_name", self.replication_handler
-        )
-        client_factory.handler = self.replication_handler
-
-        server = server_factory.buildProtocol(None)
-        client = client_factory.buildProtocol(None)
-
-        client.makeConnection(FakeTransport(server, reactor))
-
-        self.server_to_client_transport = FakeTransport(client, reactor)
-        server.makeConnection(self.server_to_client_transport)
+        self.master_store = hs.get_datastore()
+        self.slaved_store = self.worker_hs.get_datastore()
+        self.storage = hs.get_storage()
 
     def replicate(self):
         """Tell the master side of replication that something has happened, and then
diff --git a/tests/replication/slave/storage/test_events.py b/tests/replication/slave/storage/test_events.py
index f0561b30e3ea..1a88c7fb8005 100644
--- a/tests/replication/slave/storage/test_events.py
+++ b/tests/replication/slave/storage/test_events.py
@@ -17,17 +17,18 @@
 
 from synapse.api.room_versions import RoomVersions
 from synapse.events import FrozenEvent, _EventInternalMetadata, make_event_from_dict
-from synapse.events.snapshot import EventContext
 from synapse.handlers.room import RoomEventSource
 from synapse.replication.slave.storage.events import SlavedEventStore
 from synapse.storage.roommember import RoomsForUser
 
+from tests.server import FakeTransport
+
 from ._base import BaseSlavedStoreTestCase
 
-USER_ID = "@feeling:blue"
-USER_ID_2 = "@bright:blue"
+USER_ID = "@feeling:test"
+USER_ID_2 = "@bright:test"
 OUTLIER = {"outlier": True}
-ROOM_ID = "!room:blue"
+ROOM_ID = "!room:test"
 
 logger = logging.getLogger(__name__)
 
@@ -239,7 +240,8 @@ def test_get_rooms_for_user_with_stream_ordering_with_multi_event_persist(self):
         self.check("get_rooms_for_user_with_stream_ordering", (USER_ID_2,), set())
 
         # limit the replication rate
-        repl_transport = self.server_to_client_transport
+        repl_transport = self._server_transport
+        assert isinstance(repl_transport, FakeTransport)
         repl_transport.autoflush = False
 
         # build the join and message events and persist them in the same batch.
@@ -322,7 +324,6 @@ def build_event(
         type="m.room.message",
         key=None,
         internal={},
-        state=None,
         depth=None,
         prev_events=[],
         auth_events=[],
@@ -362,15 +363,8 @@ def build_event(
         event = make_event_from_dict(event_dict, internal_metadata_dict=internal)
 
         self.event_id += 1
-
-        if state is not None:
-            state_ids = {key: e.event_id for key, e in state.items()}
-            context = EventContext.with_state(
-                state_group=None, current_state_ids=state_ids, prev_state_ids=state_ids
-            )
-        else:
-            state_handler = self.hs.get_state_handler()
-            context = self.get_success(state_handler.compute_event_context(event))
+        state_handler = self.hs.get_state_handler()
+        context = self.get_success(state_handler.compute_event_context(event))
 
         self.master_store.add_push_actions_to_staging(
             event.event_id, {user_id: actions for user_id, actions in push_actions}
diff --git a/tests/replication/tcp/streams/test_account_data.py b/tests/replication/tcp/streams/test_account_data.py
new file mode 100644
index 000000000000..6a5116dd2a05
--- /dev/null
+++ b/tests/replication/tcp/streams/test_account_data.py
@@ -0,0 +1,117 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from synapse.replication.tcp.streams._base import (
+    _STREAM_UPDATE_TARGET_ROW_COUNT,
+    AccountDataStream,
+)
+
+from tests.replication._base import BaseStreamTestCase
+
+
+class AccountDataStreamTestCase(BaseStreamTestCase):
+    def test_update_function_room_account_data_limit(self):
+        """Test replication with many room account data updates
+        """
+        store = self.hs.get_datastore()
+
+        # generate lots of account data updates
+        updates = []
+        for i in range(_STREAM_UPDATE_TARGET_ROW_COUNT + 5):
+            update = "m.test_type.%i" % (i,)
+            self.get_success(
+                store.add_account_data_to_room("test_user", "test_room", update, {})
+            )
+            updates.append(update)
+
+        # also one global update
+        self.get_success(store.add_account_data_for_user("test_user", "m.global", {}))
+
+        # tell the notifier to catch up to avoid duplicate rows.
+        # workaround for https://github.com/matrix-org/synapse/issues/7360
+        # FIXME remove this when the above is fixed
+        self.replicate()
+
+        # check we're testing what we think we are: no rows should yet have been
+        # received
+        self.assertEqual([], self.test_handler.received_rdata_rows)
+
+        # now reconnect to pull the updates
+        self.reconnect()
+        self.replicate()
+
+        # we should have received all the expected rows in the right order
+        received_rows = self.test_handler.received_rdata_rows
+
+        for t in updates:
+            (stream_name, token, row) = received_rows.pop(0)
+            self.assertEqual(stream_name, AccountDataStream.NAME)
+            self.assertIsInstance(row, AccountDataStream.AccountDataStreamRow)
+            self.assertEqual(row.data_type, t)
+            self.assertEqual(row.room_id, "test_room")
+
+        (stream_name, token, row) = received_rows.pop(0)
+        self.assertIsInstance(row, AccountDataStream.AccountDataStreamRow)
+        self.assertEqual(row.data_type, "m.global")
+        self.assertIsNone(row.room_id)
+
+        self.assertEqual([], received_rows)
+
+    def test_update_function_global_account_data_limit(self):
+        """Test replication with many global account data updates
+        """
+        store = self.hs.get_datastore()
+
+        # generate lots of account data updates
+        updates = []
+        for i in range(_STREAM_UPDATE_TARGET_ROW_COUNT + 5):
+            update = "m.test_type.%i" % (i,)
+            self.get_success(store.add_account_data_for_user("test_user", update, {}))
+            updates.append(update)
+
+        # also one per-room update
+        self.get_success(
+            store.add_account_data_to_room("test_user", "test_room", "m.per_room", {})
+        )
+
+        # tell the notifier to catch up to avoid duplicate rows.
+        # workaround for https://github.com/matrix-org/synapse/issues/7360
+        # FIXME remove this when the above is fixed
+        self.replicate()
+
+        # check we're testing what we think we are: no rows should yet have been
+        # received
+        self.assertEqual([], self.test_handler.received_rdata_rows)
+
+        # now reconnect to pull the updates
+        self.reconnect()
+        self.replicate()
+
+        # we should have received all the expected rows in the right order
+        received_rows = self.test_handler.received_rdata_rows
+
+        for t in updates:
+            (stream_name, token, row) = received_rows.pop(0)
+            self.assertEqual(stream_name, AccountDataStream.NAME)
+            self.assertIsInstance(row, AccountDataStream.AccountDataStreamRow)
+            self.assertEqual(row.data_type, t)
+            self.assertIsNone(row.room_id)
+
+        (stream_name, token, row) = received_rows.pop(0)
+        self.assertIsInstance(row, AccountDataStream.AccountDataStreamRow)
+        self.assertEqual(row.data_type, "m.per_room")
+        self.assertEqual(row.room_id, "test_room")
+
+        self.assertEqual([], received_rows)
diff --git a/tests/replication/tcp/streams/test_events.py b/tests/replication/tcp/streams/test_events.py
index 8bd67bb9f16f..51bf0ef4e961 100644
--- a/tests/replication/tcp/streams/test_events.py
+++ b/tests/replication/tcp/streams/test_events.py
@@ -26,7 +26,7 @@
 from synapse.rest import admin
 from synapse.rest.client.v1 import login, room
 
-from tests.replication.tcp.streams._base import BaseStreamTestCase
+from tests.replication._base import BaseStreamTestCase
 from tests.test_utils.event_injection import inject_event, inject_member_event
 
 
diff --git a/tests/replication/tcp/streams/test_federation.py b/tests/replication/tcp/streams/test_federation.py
new file mode 100644
index 000000000000..2babea4e3e60
--- /dev/null
+++ b/tests/replication/tcp/streams/test_federation.py
@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from synapse.federation.send_queue import EduRow
+from synapse.replication.tcp.streams.federation import FederationStream
+
+from tests.replication._base import BaseStreamTestCase
+
+
+class FederationStreamTestCase(BaseStreamTestCase):
+    def _get_worker_hs_config(self) -> dict:
+        # enable federation sending on the worker
+        config = super()._get_worker_hs_config()
+        # TODO: make it so we don't need both of these
+        config["send_federation"] = True
+        config["worker_app"] = "synapse.app.federation_sender"
+        return config
+
+    def test_catchup(self):
+        """Basic test of catchup on reconnect
+
+        Makes sure that updates sent while we are offline are received later.
+        """
+        fed_sender = self.hs.get_federation_sender()
+        received_rows = self.test_handler.received_rdata_rows
+
+        fed_sender.build_and_send_edu("testdest", "m.test_edu", {"a": "b"})
+
+        self.reconnect()
+        self.reactor.advance(0)
+
+        # check we're testing what we think we are: no rows should yet have been
+        # received
+        self.assertEqual(received_rows, [])
+
+        # We should now see an attempt to connect to the master
+        request = self.handle_http_replication_attempt()
+        self.assert_request_is_get_repl_stream_updates(request, "federation")
+
+        # we should have received an update row
+        stream_name, token, row = received_rows.pop()
+        self.assertEqual(stream_name, "federation")
+        self.assertIsInstance(row, FederationStream.FederationStreamRow)
+        self.assertEqual(row.type, EduRow.TypeId)
+        edurow = EduRow.from_data(row.data)
+        self.assertEqual(edurow.edu.edu_type, "m.test_edu")
+        self.assertEqual(edurow.edu.origin, self.hs.hostname)
+        self.assertEqual(edurow.edu.destination, "testdest")
+        self.assertEqual(edurow.edu.content, {"a": "b"})
+
+        self.assertEqual(received_rows, [])
+
+        # additional updates should be transferred without an HTTP hit
+        fed_sender.build_and_send_edu("testdest", "m.test1", {"c": "d"})
+        self.reactor.advance(0)
+        # there should be no http hit
+        self.assertEqual(len(self.reactor.tcpClients), 0)
+        # ... but we should have a row
+        self.assertEqual(len(received_rows), 1)
+
+        stream_name, token, row = received_rows.pop()
+        self.assertEqual(stream_name, "federation")
+        self.assertIsInstance(row, FederationStream.FederationStreamRow)
+        self.assertEqual(row.type, EduRow.TypeId)
+        edurow = EduRow.from_data(row.data)
+        self.assertEqual(edurow.edu.edu_type, "m.test1")
+        self.assertEqual(edurow.edu.origin, self.hs.hostname)
+        self.assertEqual(edurow.edu.destination, "testdest")
+        self.assertEqual(edurow.edu.content, {"c": "d"})
diff --git a/tests/replication/tcp/streams/test_receipts.py b/tests/replication/tcp/streams/test_receipts.py
index 5853314fd408..56b062ecc1d6 100644
--- a/tests/replication/tcp/streams/test_receipts.py
+++ b/tests/replication/tcp/streams/test_receipts.py
@@ -19,7 +19,7 @@
 
 from synapse.replication.tcp.streams._base import ReceiptsStream
 
-from tests.replication.tcp.streams._base import BaseStreamTestCase
+from tests.replication._base import BaseStreamTestCase
 
 USER_ID = "@feeling:blue"
 
diff --git a/tests/replication/tcp/streams/test_typing.py b/tests/replication/tcp/streams/test_typing.py
index d25a7b194eb4..fd62b263560a 100644
--- a/tests/replication/tcp/streams/test_typing.py
+++ b/tests/replication/tcp/streams/test_typing.py
@@ -15,19 +15,14 @@
 from mock import Mock
 
 from synapse.handlers.typing import RoomMember
-from synapse.replication.http import streams
 from synapse.replication.tcp.streams import TypingStream
 
-from tests.replication.tcp.streams._base import BaseStreamTestCase
+from tests.replication._base import BaseStreamTestCase
 
 USER_ID = "@feeling:blue"
 
 
 class TypingStreamTestCase(BaseStreamTestCase):
-    servlets = [
-        streams.register_servlets,
-    ]
-
     def _build_replication_data_handler(self):
         return Mock(wraps=super()._build_replication_data_handler())
 
diff --git a/tests/replication/tcp/test_commands.py b/tests/replication/tcp/test_commands.py
index 7ddfd0a733c0..60c10a441a87 100644
--- a/tests/replication/tcp/test_commands.py
+++ b/tests/replication/tcp/test_commands.py
@@ -30,7 +30,7 @@ def test_parse_one_word_command(self):
     def test_parse_rdata(self):
         line = 'RDATA events master 6287863 ["ev", ["$eventid", "!roomid", "type", null, null, null]]'
         cmd = parse_command_from_line(line)
-        self.assertIsInstance(cmd, RdataCommand)
+        assert isinstance(cmd, RdataCommand)
         self.assertEqual(cmd.stream_name, "events")
         self.assertEqual(cmd.instance_name, "master")
         self.assertEqual(cmd.token, 6287863)
@@ -38,7 +38,7 @@ def test_parse_rdata(self):
     def test_parse_rdata_batch(self):
         line = 'RDATA presence master batch ["@foo:example.com", "online"]'
         cmd = parse_command_from_line(line)
-        self.assertIsInstance(cmd, RdataCommand)
+        assert isinstance(cmd, RdataCommand)
         self.assertEqual(cmd.stream_name, "presence")
         self.assertEqual(cmd.instance_name, "master")
         self.assertIsNone(cmd.token)
diff --git a/tests/rest/admin/test_room.py b/tests/rest/admin/test_room.py
index 249c93722f47..54cd24bf645d 100644
--- a/tests/rest/admin/test_room.py
+++ b/tests/rest/admin/test_room.py
@@ -701,6 +701,47 @@ def _search_test(
         _search_test(None, "bar")
         _search_test(None, "", expected_http_code=400)
 
+    def test_single_room(self):
+        """Test that a single room can be requested correctly"""
+        # Create two test rooms
+        room_id_1 = self.helper.create_room_as(self.admin_user, tok=self.admin_user_tok)
+        room_id_2 = self.helper.create_room_as(self.admin_user, tok=self.admin_user_tok)
+
+        room_name_1 = "something"
+        room_name_2 = "else"
+
+        # Set the name for each room
+        self.helper.send_state(
+            room_id_1, "m.room.name", {"name": room_name_1}, tok=self.admin_user_tok,
+        )
+        self.helper.send_state(
+            room_id_2, "m.room.name", {"name": room_name_2}, tok=self.admin_user_tok,
+        )
+
+        url = "/_synapse/admin/v1/rooms/%s" % (room_id_1,)
+        request, channel = self.make_request(
+            "GET", url.encode("ascii"), access_token=self.admin_user_tok,
+        )
+        self.render(request)
+        self.assertEqual(200, channel.code, msg=channel.json_body)
+
+        self.assertIn("room_id", channel.json_body)
+        self.assertIn("name", channel.json_body)
+        self.assertIn("canonical_alias", channel.json_body)
+        self.assertIn("joined_members", channel.json_body)
+        self.assertIn("joined_local_members", channel.json_body)
+        self.assertIn("version", channel.json_body)
+        self.assertIn("creator", channel.json_body)
+        self.assertIn("encryption", channel.json_body)
+        self.assertIn("federatable", channel.json_body)
+        self.assertIn("public", channel.json_body)
+        self.assertIn("join_rules", channel.json_body)
+        self.assertIn("guest_access", channel.json_body)
+        self.assertIn("history_visibility", channel.json_body)
+        self.assertIn("state_events", channel.json_body)
+
+        self.assertEqual(room_id_1, channel.json_body["room_id"])
+
 
 class JoinAliasRoomTestCase(unittest.HomeserverTestCase):
 
diff --git a/tests/rest/client/v1/test_login.py b/tests/rest/client/v1/test_login.py
index 1856c7ffd5a6..eb8f6264fdb4 100644
--- a/tests/rest/client/v1/test_login.py
+++ b/tests/rest/client/v1/test_login.py
@@ -4,7 +4,7 @@
 from mock import Mock
 
 import synapse.rest.admin
-from synapse.rest.client.v1 import login
+from synapse.rest.client.v1 import login, logout
 from synapse.rest.client.v2_alpha import devices
 from synapse.rest.client.v2_alpha.account import WhoamiRestServlet
 
@@ -20,6 +20,7 @@ class LoginRestServletTestCase(unittest.HomeserverTestCase):
     servlets = [
         synapse.rest.admin.register_servlets_for_client_rest_resource,
         login.register_servlets,
+        logout.register_servlets,
         devices.register_servlets,
         lambda hs, http_server: WhoamiRestServlet(hs).register(http_server),
     ]
@@ -256,6 +257,72 @@ def _delete_device(self, access_token, user_id, password, device_id):
         self.render(request)
         self.assertEquals(channel.code, 200, channel.result)
 
+    @override_config({"session_lifetime": "24h"})
+    def test_session_can_hard_logout_after_being_soft_logged_out(self):
+        self.register_user("kermit", "monkey")
+
+        # log in as normal
+        access_token = self.login("kermit", "monkey")
+
+        # we should now be able to make requests with the access token
+        request, channel = self.make_request(
+            b"GET", TEST_URL, access_token=access_token
+        )
+        self.render(request)
+        self.assertEquals(channel.code, 200, channel.result)
+
+        # time passes
+        self.reactor.advance(24 * 3600)
+
+        # ... and we should be soft-logouted
+        request, channel = self.make_request(
+            b"GET", TEST_URL, access_token=access_token
+        )
+        self.render(request)
+        self.assertEquals(channel.code, 401, channel.result)
+        self.assertEquals(channel.json_body["errcode"], "M_UNKNOWN_TOKEN")
+        self.assertEquals(channel.json_body["soft_logout"], True)
+
+        # Now try to hard logout this session
+        request, channel = self.make_request(
+            b"POST", "/logout", access_token=access_token
+        )
+        self.render(request)
+        self.assertEquals(channel.result["code"], b"200", channel.result)
+
+    @override_config({"session_lifetime": "24h"})
+    def test_session_can_hard_logout_all_sessions_after_being_soft_logged_out(self):
+        self.register_user("kermit", "monkey")
+
+        # log in as normal
+        access_token = self.login("kermit", "monkey")
+
+        # we should now be able to make requests with the access token
+        request, channel = self.make_request(
+            b"GET", TEST_URL, access_token=access_token
+        )
+        self.render(request)
+        self.assertEquals(channel.code, 200, channel.result)
+
+        # time passes
+        self.reactor.advance(24 * 3600)
+
+        # ... and we should be soft-logouted
+        request, channel = self.make_request(
+            b"GET", TEST_URL, access_token=access_token
+        )
+        self.render(request)
+        self.assertEquals(channel.code, 401, channel.result)
+        self.assertEquals(channel.json_body["errcode"], "M_UNKNOWN_TOKEN")
+        self.assertEquals(channel.json_body["soft_logout"], True)
+
+        # Now try to hard log out all of the user's sessions
+        request, channel = self.make_request(
+            b"POST", "/logout/all", access_token=access_token
+        )
+        self.render(request)
+        self.assertEquals(channel.result["code"], b"200", channel.result)
+
 
 class CASTestCase(unittest.HomeserverTestCase):
 
diff --git a/tests/rest/client/v2_alpha/test_register.py b/tests/rest/client/v2_alpha/test_register.py
index a68a96f61861..5637ce20907f 100644
--- a/tests/rest/client/v2_alpha/test_register.py
+++ b/tests/rest/client/v2_alpha/test_register.py
@@ -25,7 +25,7 @@
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes
 from synapse.appservice import ApplicationService
-from synapse.rest.client.v1 import login
+from synapse.rest.client.v1 import login, logout
 from synapse.rest.client.v2_alpha import account, account_validity, register, sync
 
 from tests import unittest
@@ -313,6 +313,7 @@ class AccountValidityTestCase(unittest.HomeserverTestCase):
         synapse.rest.admin.register_servlets_for_client_rest_resource,
         login.register_servlets,
         sync.register_servlets,
+        logout.register_servlets,
         account_validity.register_servlets,
     ]
 
@@ -405,6 +406,39 @@ def test_manual_expire(self):
             channel.json_body["errcode"], Codes.EXPIRED_ACCOUNT, channel.result
         )
 
+    def test_logging_out_expired_user(self):
+        user_id = self.register_user("kermit", "monkey")
+        tok = self.login("kermit", "monkey")
+
+        self.register_user("admin", "adminpassword", admin=True)
+        admin_tok = self.login("admin", "adminpassword")
+
+        url = "/_matrix/client/unstable/admin/account_validity/validity"
+        params = {
+            "user_id": user_id,
+            "expiration_ts": 0,
+            "enable_renewal_emails": False,
+        }
+        request_data = json.dumps(params)
+        request, channel = self.make_request(
+            b"POST", url, request_data, access_token=admin_tok
+        )
+        self.render(request)
+        self.assertEquals(channel.result["code"], b"200", channel.result)
+
+        # Try to log the user out
+        request, channel = self.make_request(b"POST", "/logout", access_token=tok)
+        self.render(request)
+        self.assertEquals(channel.result["code"], b"200", channel.result)
+
+        # Log the user in again (allowed for expired accounts)
+        tok = self.login("kermit", "monkey")
+
+        # Try to log out all of the user's sessions
+        request, channel = self.make_request(b"POST", "/logout/all", access_token=tok)
+        self.render(request)
+        self.assertEquals(channel.result["code"], b"200", channel.result)
+
 
 class AccountValidityRenewalByEmailTestCase(unittest.HomeserverTestCase):
 
diff --git a/tests/storage/test__base.py b/tests/storage/test__base.py
index e37260a820c6..5a50e4fdd454 100644
--- a/tests/storage/test__base.py
+++ b/tests/storage/test__base.py
@@ -25,8 +25,8 @@
 from tests import unittest
 
 
-class CacheTestCase(unittest.TestCase):
-    def setUp(self):
+class CacheTestCase(unittest.HomeserverTestCase):
+    def prepare(self, reactor, clock, homeserver):
         self.cache = Cache("test")
 
     def test_empty(self):
@@ -96,7 +96,7 @@ def test_eviction_lru(self):
         cache.get(3)
 
 
-class CacheDecoratorTestCase(unittest.TestCase):
+class CacheDecoratorTestCase(unittest.HomeserverTestCase):
     @defer.inlineCallbacks
     def test_passthrough(self):
         class A(object):
@@ -239,7 +239,7 @@ def test_eviction_context(self):
         callcount2 = [0]
 
         class A(object):
-            @cached(max_entries=4)  # HACK: This makes it 2 due to cache factor
+            @cached(max_entries=2)
             def func(self, key):
                 callcount[0] += 1
                 return key
diff --git a/tests/storage/test_appservice.py b/tests/storage/test_appservice.py
index 31710949a820..ef296e7dab14 100644
--- a/tests/storage/test_appservice.py
+++ b/tests/storage/test_appservice.py
@@ -43,7 +43,7 @@ def setUp(self):
         )
 
         hs.config.app_service_config_files = self.as_yaml_files
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         self.as_token = "token1"
@@ -110,7 +110,7 @@ def setUp(self):
         )
 
         hs.config.app_service_config_files = self.as_yaml_files
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         self.as_list = [
@@ -422,7 +422,7 @@ def test_unique_works(self):
         )
 
         hs.config.app_service_config_files = [f1, f2]
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         database = hs.get_datastores().databases[0]
@@ -440,7 +440,7 @@ def test_duplicate_ids(self):
         )
 
         hs.config.app_service_config_files = [f1, f2]
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         with self.assertRaises(ConfigError) as cm:
@@ -464,7 +464,7 @@ def test_duplicate_as_tokens(self):
         )
 
         hs.config.app_service_config_files = [f1, f2]
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         with self.assertRaises(ConfigError) as cm:
diff --git a/tests/storage/test_base.py b/tests/storage/test_base.py
index cdee0a9e60b4..278961c33144 100644
--- a/tests/storage/test_base.py
+++ b/tests/storage/test_base.py
@@ -51,7 +51,8 @@ def runWithConnection(func, *args, **kwargs):
 
         config = Mock()
         config._disable_native_upserts = True
-        config.event_cache_size = 1
+        config.caches = Mock()
+        config.caches.event_cache_size = 1
         hs = TestHomeServer("test", config=config)
 
         sqlite_config = {"name": "sqlite3"}
diff --git a/tests/storage/test_event_push_actions.py b/tests/storage/test_event_push_actions.py
index d4bcf1821e56..b45bc9c1151f 100644
--- a/tests/storage/test_event_push_actions.py
+++ b/tests/storage/test_event_push_actions.py
@@ -35,6 +35,7 @@ class EventPushActionsStoreTestCase(tests.unittest.TestCase):
     def setUp(self):
         hs = yield tests.utils.setup_test_homeserver(self.addCleanup)
         self.store = hs.get_datastore()
+        self.persist_events_store = hs.get_datastores().persist_events
 
     @defer.inlineCallbacks
     def test_get_unread_push_actions_for_user_in_range_for_http(self):
@@ -76,7 +77,7 @@ def _inject_actions(stream, action):
             )
             yield self.store.db.runInteraction(
                 "",
-                self.store._set_push_actions_for_event_and_users_txn,
+                self.persist_events_store._set_push_actions_for_event_and_users_txn,
                 [(event, None)],
                 [(event, None)],
             )
diff --git a/tests/storage/test_id_generators.py b/tests/storage/test_id_generators.py
new file mode 100644
index 000000000000..55e9ecf2641c
--- /dev/null
+++ b/tests/storage/test_id_generators.py
@@ -0,0 +1,184 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from synapse.storage.database import Database
+from synapse.storage.util.id_generators import MultiWriterIdGenerator
+
+from tests.unittest import HomeserverTestCase
+from tests.utils import USE_POSTGRES_FOR_TESTS
+
+
+class MultiWriterIdGeneratorTestCase(HomeserverTestCase):
+    if not USE_POSTGRES_FOR_TESTS:
+        skip = "Requires Postgres"
+
+    def prepare(self, reactor, clock, hs):
+        self.store = hs.get_datastore()
+        self.db = self.store.db  # type: Database
+
+        self.get_success(self.db.runInteraction("_setup_db", self._setup_db))
+
+    def _setup_db(self, txn):
+        txn.execute("CREATE SEQUENCE foobar_seq")
+        txn.execute(
+            """
+            CREATE TABLE foobar (
+                stream_id BIGINT NOT NULL,
+                instance_name TEXT NOT NULL,
+                data TEXT
+            );
+            """
+        )
+
+    def _create_id_generator(self, instance_name="master") -> MultiWriterIdGenerator:
+        def _create(conn):
+            return MultiWriterIdGenerator(
+                conn,
+                self.db,
+                instance_name=instance_name,
+                table="foobar",
+                instance_column="instance_name",
+                id_column="stream_id",
+                sequence_name="foobar_seq",
+            )
+
+        return self.get_success(self.db.runWithConnection(_create))
+
+    def _insert_rows(self, instance_name: str, number: int):
+        def _insert(txn):
+            for _ in range(number):
+                txn.execute(
+                    "INSERT INTO foobar VALUES (nextval('foobar_seq'), ?)",
+                    (instance_name,),
+                )
+
+        self.get_success(self.db.runInteraction("test_single_instance", _insert))
+
+    def test_empty(self):
+        """Test an ID generator against an empty database gives sensible
+        current positions.
+        """
+
+        id_gen = self._create_id_generator()
+
+        # The table is empty so we expect an empty map for positions
+        self.assertEqual(id_gen.get_positions(), {})
+
+    def test_single_instance(self):
+        """Test that reads and writes from a single process are handled
+        correctly.
+        """
+
+        # Prefill table with 7 rows written by 'master'
+        self._insert_rows("master", 7)
+
+        id_gen = self._create_id_generator()
+
+        self.assertEqual(id_gen.get_positions(), {"master": 7})
+        self.assertEqual(id_gen.get_current_token("master"), 7)
+
+        # Try allocating a new ID gen and check that we only see position
+        # advanced after we leave the context manager.
+
+        async def _get_next_async():
+            with await id_gen.get_next() as stream_id:
+                self.assertEqual(stream_id, 8)
+
+                self.assertEqual(id_gen.get_positions(), {"master": 7})
+                self.assertEqual(id_gen.get_current_token("master"), 7)
+
+        self.get_success(_get_next_async())
+
+        self.assertEqual(id_gen.get_positions(), {"master": 8})
+        self.assertEqual(id_gen.get_current_token("master"), 8)
+
+    def test_multi_instance(self):
+        """Test that reads and writes from multiple processes are handled
+        correctly.
+        """
+        self._insert_rows("first", 3)
+        self._insert_rows("second", 4)
+
+        first_id_gen = self._create_id_generator("first")
+        second_id_gen = self._create_id_generator("second")
+
+        self.assertEqual(first_id_gen.get_positions(), {"first": 3, "second": 7})
+        self.assertEqual(first_id_gen.get_current_token("first"), 3)
+        self.assertEqual(first_id_gen.get_current_token("second"), 7)
+
+        # Try allocating a new ID gen and check that we only see position
+        # advanced after we leave the context manager.
+
+        async def _get_next_async():
+            with await first_id_gen.get_next() as stream_id:
+                self.assertEqual(stream_id, 8)
+
+                self.assertEqual(
+                    first_id_gen.get_positions(), {"first": 3, "second": 7}
+                )
+
+        self.get_success(_get_next_async())
+
+        self.assertEqual(first_id_gen.get_positions(), {"first": 8, "second": 7})
+
+        # However the ID gen on the second instance won't have seen the update
+        self.assertEqual(second_id_gen.get_positions(), {"first": 3, "second": 7})
+
+        # ... but calling `get_next` on the second instance should give a unique
+        # stream ID
+
+        async def _get_next_async():
+            with await second_id_gen.get_next() as stream_id:
+                self.assertEqual(stream_id, 9)
+
+                self.assertEqual(
+                    second_id_gen.get_positions(), {"first": 3, "second": 7}
+                )
+
+        self.get_success(_get_next_async())
+
+        self.assertEqual(second_id_gen.get_positions(), {"first": 3, "second": 9})
+
+        # If the second ID gen gets told about the first, it correctly updates
+        second_id_gen.advance("first", 8)
+        self.assertEqual(second_id_gen.get_positions(), {"first": 8, "second": 9})
+
+    def test_get_next_txn(self):
+        """Test that the `get_next_txn` function works correctly.
+        """
+
+        # Prefill table with 7 rows written by 'master'
+        self._insert_rows("master", 7)
+
+        id_gen = self._create_id_generator()
+
+        self.assertEqual(id_gen.get_positions(), {"master": 7})
+        self.assertEqual(id_gen.get_current_token("master"), 7)
+
+        # Try allocating a new ID gen and check that we only see position
+        # advanced after we leave the context manager.
+
+        def _get_next_txn(txn):
+            stream_id = id_gen.get_next_txn(txn)
+            self.assertEqual(stream_id, 8)
+
+            self.assertEqual(id_gen.get_positions(), {"master": 7})
+            self.assertEqual(id_gen.get_current_token("master"), 7)
+
+        self.get_success(self.db.runInteraction("test", _get_next_txn))
+
+        self.assertEqual(id_gen.get_positions(), {"master": 8})
+        self.assertEqual(id_gen.get_current_token("master"), 8)
diff --git a/tests/storage/test_room.py b/tests/storage/test_room.py
index 086adeb8fd39..3b78d488965b 100644
--- a/tests/storage/test_room.py
+++ b/tests/storage/test_room.py
@@ -55,6 +55,17 @@ def test_get_room(self):
             (yield self.store.get_room(self.room.to_string())),
         )
 
+    @defer.inlineCallbacks
+    def test_get_room_with_stats(self):
+        self.assertDictContainsSubset(
+            {
+                "room_id": self.room.to_string(),
+                "creator": self.u_creator.to_string(),
+                "public": True,
+            },
+            (yield self.store.get_room_with_stats(self.room.to_string())),
+        )
+
 
 class RoomEventsStoreTestCase(unittest.TestCase):
     @defer.inlineCallbacks
diff --git a/tests/test_event_auth.py b/tests/test_event_auth.py
index 6c2351cf559f..69b4c5d6c2f9 100644
--- a/tests/test_event_auth.py
+++ b/tests/test_event_auth.py
@@ -136,21 +136,18 @@ def test_msc2432_alias_event(self):
 
         # creator should be able to send aliases
         event_auth.check(
-            RoomVersions.MSC2432_DEV,
-            _alias_event(creator),
-            auth_events,
-            do_sig_check=False,
+            RoomVersions.V6, _alias_event(creator), auth_events, do_sig_check=False,
         )
 
         # No particular checks are done on the state key.
         event_auth.check(
-            RoomVersions.MSC2432_DEV,
+            RoomVersions.V6,
             _alias_event(creator, state_key=""),
             auth_events,
             do_sig_check=False,
         )
         event_auth.check(
-            RoomVersions.MSC2432_DEV,
+            RoomVersions.V6,
             _alias_event(creator, state_key="test.com"),
             auth_events,
             do_sig_check=False,
@@ -159,8 +156,38 @@ def test_msc2432_alias_event(self):
         # Per standard auth rules, the member must be in the room.
         with self.assertRaises(AuthError):
             event_auth.check(
-                RoomVersions.MSC2432_DEV,
-                _alias_event(other),
+                RoomVersions.V6, _alias_event(other), auth_events, do_sig_check=False,
+            )
+
+    def test_msc2209(self):
+        """
+        Notifications power levels get checked due to MSC2209.
+        """
+        creator = "@creator:example.com"
+        pleb = "@joiner:example.com"
+
+        auth_events = {
+            ("m.room.create", ""): _create_event(creator),
+            ("m.room.member", creator): _join_event(creator),
+            ("m.room.power_levels", ""): _power_levels_event(
+                creator, {"state_default": "30", "users": {pleb: "30"}}
+            ),
+            ("m.room.member", pleb): _join_event(pleb),
+        }
+
+        # pleb should be able to modify the notifications power level.
+        event_auth.check(
+            RoomVersions.V1,
+            _power_levels_event(pleb, {"notifications": {"room": 100}}),
+            auth_events,
+            do_sig_check=False,
+        )
+
+        # But an MSC2209 room rejects this change.
+        with self.assertRaises(AuthError):
+            event_auth.check(
+                RoomVersions.V6,
+                _power_levels_event(pleb, {"notifications": {"room": 100}}),
                 auth_events,
                 do_sig_check=False,
             )
diff --git a/tests/test_metrics.py b/tests/test_metrics.py
index 270f853d602e..f5f63d8ed699 100644
--- a/tests/test_metrics.py
+++ b/tests/test_metrics.py
@@ -15,6 +15,7 @@
 # limitations under the License.
 
 from synapse.metrics import REGISTRY, InFlightGauge, generate_latest
+from synapse.util.caches.descriptors import Cache
 
 from tests import unittest
 
@@ -129,3 +130,36 @@ def test_get_build(self):
         self.assertTrue(b"osversion=" in items[0])
         self.assertTrue(b"pythonversion=" in items[0])
         self.assertTrue(b"version=" in items[0])
+
+
+class CacheMetricsTests(unittest.HomeserverTestCase):
+    def test_cache_metric(self):
+        """
+        Caches produce metrics reflecting their state when scraped.
+        """
+        CACHE_NAME = "cache_metrics_test_fgjkbdfg"
+        cache = Cache(CACHE_NAME, max_entries=777)
+
+        items = {
+            x.split(b"{")[0].decode("ascii"): x.split(b" ")[1].decode("ascii")
+            for x in filter(
+                lambda x: b"cache_metrics_test_fgjkbdfg" in x,
+                generate_latest(REGISTRY).split(b"\n"),
+            )
+        }
+
+        self.assertEqual(items["synapse_util_caches_cache_size"], "0.0")
+        self.assertEqual(items["synapse_util_caches_cache_max_size"], "777.0")
+
+        cache.prefill("1", "hi")
+
+        items = {
+            x.split(b"{")[0].decode("ascii"): x.split(b" ")[1].decode("ascii")
+            for x in filter(
+                lambda x: b"cache_metrics_test_fgjkbdfg" in x,
+                generate_latest(REGISTRY).split(b"\n"),
+            )
+        }
+
+        self.assertEqual(items["synapse_util_caches_cache_size"], "1.0")
+        self.assertEqual(items["synapse_util_caches_cache_max_size"], "777.0")
diff --git a/tests/util/test_expiring_cache.py b/tests/util/test_expiring_cache.py
index 50bc7702d20b..49ffeebd0ed5 100644
--- a/tests/util/test_expiring_cache.py
+++ b/tests/util/test_expiring_cache.py
@@ -21,7 +21,7 @@
 from .. import unittest
 
 
-class ExpiringCacheTestCase(unittest.TestCase):
+class ExpiringCacheTestCase(unittest.HomeserverTestCase):
     def test_get_set(self):
         clock = MockClock()
         cache = ExpiringCache("test", clock, max_len=1)
diff --git a/tests/util/test_lrucache.py b/tests/util/test_lrucache.py
index 786947375df2..0adb2174af98 100644
--- a/tests/util/test_lrucache.py
+++ b/tests/util/test_lrucache.py
@@ -22,7 +22,7 @@
 from .. import unittest
 
 
-class LruCacheTestCase(unittest.TestCase):
+class LruCacheTestCase(unittest.HomeserverTestCase):
     def test_get_set(self):
         cache = LruCache(1)
         cache["key"] = "value"
@@ -84,7 +84,7 @@ def test_clear(self):
         self.assertEquals(len(cache), 0)
 
 
-class LruCacheCallbacksTestCase(unittest.TestCase):
+class LruCacheCallbacksTestCase(unittest.HomeserverTestCase):
     def test_get(self):
         m = Mock()
         cache = LruCache(1)
@@ -233,7 +233,7 @@ def test_eviction(self):
         self.assertEquals(m3.call_count, 1)
 
 
-class LruCacheSizedTestCase(unittest.TestCase):
+class LruCacheSizedTestCase(unittest.HomeserverTestCase):
     def test_evict(self):
         cache = LruCache(5, size_callback=len)
         cache["key1"] = [0]
diff --git a/tests/util/test_stream_change_cache.py b/tests/util/test_stream_change_cache.py
index 6857933540d6..13b753e367fa 100644
--- a/tests/util/test_stream_change_cache.py
+++ b/tests/util/test_stream_change_cache.py
@@ -1,11 +1,9 @@
-from mock import patch
-
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 from tests import unittest
 
 
-class StreamChangeCacheTests(unittest.TestCase):
+class StreamChangeCacheTests(unittest.HomeserverTestCase):
     """
     Tests for StreamChangeCache.
     """
@@ -54,7 +52,6 @@ def test_has_entity_changed(self):
         self.assertTrue(cache.has_entity_changed("user@foo.com", 0))
         self.assertTrue(cache.has_entity_changed("not@here.website", 0))
 
-    @patch("synapse.util.caches.CACHE_SIZE_FACTOR", 1.0)
     def test_entity_has_changed_pops_off_start(self):
         """
         StreamChangeCache.entity_has_changed will respect the max size and
diff --git a/tests/utils.py b/tests/utils.py
index f9be62b499fd..59c020a051e9 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -167,6 +167,7 @@ def default_config(name, parse=False):
         # disable user directory updates, because they get done in the
         # background, which upsets the test runner.
         "update_user_directory": False,
+        "caches": {"global_factor": 1},
     }
 
     if parse:
diff --git a/tox.ini b/tox.ini
index 8aef52021dbe..3bb4d45e2a97 100644
--- a/tox.ini
+++ b/tox.ini
@@ -180,16 +180,17 @@ commands = mypy \
             synapse/api \
             synapse/appservice \
             synapse/config \
+            synapse/event_auth.py \
             synapse/events/spamcheck.py \
-            synapse/federation/federation_base.py \
-            synapse/federation/federation_client.py \
-            synapse/federation/federation_server.py \
-            synapse/federation/sender \
-            synapse/federation/transport \
+            synapse/federation \
             synapse/handlers/auth.py \
             synapse/handlers/cas_handler.py \
             synapse/handlers/directory.py \
+            synapse/handlers/oidc_handler.py \
             synapse/handlers/presence.py \
+            synapse/handlers/room_member.py \
+            synapse/handlers/room_member_worker.py \
+            synapse/handlers/saml_handler.py \
             synapse/handlers/sync.py \
             synapse/handlers/ui_auth \
             synapse/logging/ \
@@ -203,9 +204,10 @@ commands = mypy \
             synapse/storage/data_stores/main/ui_auth.py \
             synapse/storage/database.py \
             synapse/storage/engines \
+            synapse/storage/util \
             synapse/streams \
             synapse/util/caches/stream_change_cache.py \
-            tests/replication/tcp/streams \
+            tests/replication \
             tests/test_utils \
             tests/rest/client/v2_alpha/test_auth.py \
             tests/util/test_stream_change_cache.py