Move event stream handling out of slave store. (#7491)

This allows us to have the logic on both master and workers, which is necessary to move event persistence off master.

We also combine the instantiation of ID generators from DataStore and slave stores to the base worker stores. This allows us to select which process writes events independently of the master/worker splits.

changelog.d/7491.misc

@@ -0,0 +1 @@
+Move event stream handling out of slave store.

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()
@@ -92,81 +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, instance_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().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,))

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(),

synapse/storage/data_stores/main/__init__.py

@@ -24,7 +24,6 @@
 from synapse.storage.database import Database
 from synapse.storage.engines import PostgresEngine
 from synapse.storage.util.id_generators import (
-    ChainedIdGenerator,
     IdGenerator,
     MultiWriterIdGenerator,
     StreamIdGenerator,
@@ -125,19 +124,6 @@ def __init__(self, database: Database, db_conn, 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"
         )
@@ -164,9 +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")]
         )

synapse/storage/data_stores/main/cache.py

@@ -16,8 +16,13 @@
 
 import itertools
 import logging
-from typing import Any, Iterable, Optional
+from typing import Any, Iterable, Optional, Tuple
 
+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
@@ -66,7 +71,22 @@ def get_all_updated_caches_txn(txn):
         )
 
     def process_replication_rows(self, stream_name, instance_name, token, rows):
-        if stream_name == "caches":
+        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)
 
@@ -85,6 +105,84 @@ def process_replication_rows(self, stream_name, instance_name, token, rows):
 
         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,))
+
+    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.
+
+        This should only be used to invalidate caches where slaves won't
+        otherwise know from other replication streams that the cache should
+        be invalidated.
+        """
+        cache_func = getattr(self, cache_name, None)
+        if not cache_func:
+            return
+
+        cache_func.invalidate(keys)
+        await self.db.runInteraction(
+            "invalidate_cache_and_stream",
+            self._send_invalidation_to_replication,
+            cache_func.__name__,
+            keys,
+        )
+
     def _invalidate_cache_and_stream(self, txn, cache_func, keys):
         """Invalidates the cache and adds it to the cache stream so slaves
         will know to invalidate their caches.

synapse/storage/data_stores/main/events_worker.py

@@ -37,8 +37,10 @@
 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, cached, cachedInlineCallbacks
 from synapse.util.iterutils import batch_iter
@@ -74,6 +76,31 @@ 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,
@@ -85,6 +112,14 @@ def __init__(self, database: Database, db_conn, hs):
         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.