ra_server: Add a new last_applied state query
#462
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
[Why] `ra_server_proc` was querying `overview` up until now to get the last applied index as part of the handling of conditions for queries. This call was very expensive, leading to really poor performance of conditional queries (like a whopping 3000 times slower). [How] We add a dedicated state query to get the `last_applied` value only.
…eded [Why] If the query has a condition, the result of the call to `determine_leader/2` is not used. Furthermore, it is called again by another function further down the line.
the-mikedavis
approved these changes
Jul 26, 2024
dumbbell
added a commit
to rabbitmq/khepri
that referenced
this pull request
Jul 31, 2024
[Why] `ra:member_overview/2` is a very expensive call. [How] We just need the last index and the current term from the leader and `ra:key_metrics/2` provides this piece of information too. The difference is huge: in my benchmark, the query rate goes from 15 queries per second to 100k. This is in association with a related change in Ra; see rabbitmq/ra#462.
dumbbell
added a commit
to rabbitmq/khepri
that referenced
this pull request
Aug 13, 2024
[Why] `ra:member_overview/2` is a very expensive call. [How] We just need the last index and the current term from the leader and `ra:key_metrics/2` provides this piece of information too. The difference is huge: in my benchmark, the query rate goes from 15 queries per second to 100k. This is in association with a related change in Ra; see rabbitmq/ra#462.
dumbbell
added a commit
to rabbitmq/khepri
that referenced
this pull request
Aug 13, 2024
[Why] `ra:member_overview/2` is a very expensive call. [How] We just need the last index and the current term from the leader and `ra:key_metrics/2` provides this piece of information too. The difference is huge: in my benchmark, the query rate goes from 15 queries per second to 100k. This is in association with a related change in Ra; see rabbitmq/ra#462.
dumbbell
added a commit
to rabbitmq/khepri
that referenced
this pull request
Aug 13, 2024
[Why] `ra:member_overview/2` is a very expensive call. [How] We just need the last index and the current term from the leader and `ra:key_metrics/2` provides this piece of information too. The difference is huge: in my benchmark, the query rate goes from 15 queries per second to 100k. This is in association with a related change in Ra; see rabbitmq/ra#462.
dumbbell
added a commit
to rabbitmq/khepri
that referenced
this pull request
Aug 14, 2024
[Why] `ra:member_overview/2` is a very expensive call. [How] We just need the last index and the current term from the leader and `ra:key_metrics/2` provides this piece of information too. The difference is huge: in my benchmark, the query rate goes from 15 queries per second to 100k. This is in association with a related change in Ra; see rabbitmq/ra#462.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Why
ra_server_procwas queryingoverviewup until now to get the last applied index as part of the handling of conditions for queries.This call was very expensive, leading to really poor performance of conditional queries (like a whopping 3000 times slower).
How
We add a dedicated state query to get the
last_appliedvalue only.