diff options
Diffstat (limited to '')
| -rw-r--r-- | changelog.d/9935.feature | 1 | ||||
| -rw-r--r-- | synapse/handlers/federation.py | 123 |
2 files changed, 55 insertions, 69 deletions
diff --git a/changelog.d/9935.feature b/changelog.d/9935.feature new file mode 100644 index 0000000000..eeda5bf50e --- /dev/null +++ b/changelog.d/9935.feature @@ -0,0 +1 @@ +Improve performance of backfilling in large rooms. diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index e8330a2b50..798ed75b30 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -552,8 +552,12 @@ class FederationHandler(BaseHandler): destination: str, room_id: str, event_id: str, - ) -> Tuple[List[EventBase], List[EventBase]]: - """Requests all of the room state at a given event from a remote homeserver. + ) -> List[EventBase]: + """Requests all of the room state at a given event from a remote + homeserver. + + Will also fetch any missing events reported in the `auth_chain_ids` + section of `/state_ids`. Args: destination: The remote homeserver to query for the state. @@ -561,8 +565,7 @@ class FederationHandler(BaseHandler): event_id: The id of the event we want the state at. Returns: - A list of events in the state, not including the event itself, and - a list of events in the auth chain for the given event. + A list of events in the state, not including the event itself. """ ( state_event_ids, @@ -571,68 +574,53 @@ class FederationHandler(BaseHandler): destination, room_id, event_id=event_id ) - desired_events = set(state_event_ids + auth_event_ids) - - event_map = await self._get_events_from_store_or_dest( - destination, room_id, desired_events - ) + # Fetch the state events from the DB, and check we have the auth events. + event_map = await self.store.get_events(state_event_ids, allow_rejected=True) + auth_events_in_store = await self.store.have_seen_events(auth_event_ids) - failed_to_fetch = desired_events - event_map.keys() - if failed_to_fetch: - logger.warning( - "Failed to fetch missing state/auth events for %s %s", - event_id, - failed_to_fetch, + # Check for missing events. We handle state and auth event seperately, + # as we want to pull the state from the DB, but we don't for the auth + # events. (Note: we likely won't use the majority of the auth chain, and + # it can be *huge* for large rooms, so it's worth ensuring that we don't + # unnecessarily pull it from the DB). + missing_state_events = set(state_event_ids) - set(event_map) + missing_auth_events = set(auth_event_ids) - set(auth_events_in_store) + if missing_state_events or missing_auth_events: + await self._get_events_and_persist( + destination=destination, + room_id=room_id, + events=missing_state_events | missing_auth_events, ) - remote_state = [ - event_map[e_id] for e_id in state_event_ids if e_id in event_map - ] - - auth_chain = [event_map[e_id] for e_id in auth_event_ids if e_id in event_map] - auth_chain.sort(key=lambda e: e.depth) - - return remote_state, auth_chain - - async def _get_events_from_store_or_dest( - self, destination: str, room_id: str, event_ids: Iterable[str] - ) -> Dict[str, EventBase]: - """Fetch events from a remote destination, checking if we already have them. - - Persists any events we don't already have as outliers. - - If we fail to fetch any of the events, a warning will be logged, and the event - will be omitted from the result. Likewise, any events which turn out not to - be in the given room. + if missing_state_events: + new_events = await self.store.get_events( + missing_state_events, allow_rejected=True + ) + event_map.update(new_events) - This function *does not* automatically get missing auth events of the - newly fetched events. Callers must include the full auth chain of - of the missing events in the `event_ids` argument, to ensure that any - missing auth events are correctly fetched. + missing_state_events.difference_update(new_events) - Returns: - map from event_id to event - """ - fetched_events = await self.store.get_events(event_ids, allow_rejected=True) - - missing_events = set(event_ids) - fetched_events.keys() + if missing_state_events: + logger.warning( + "Failed to fetch missing state events for %s %s", + event_id, + missing_state_events, + ) - if missing_events: - logger.debug( - "Fetching unknown state/auth events %s for room %s", - missing_events, - room_id, - ) + if missing_auth_events: + auth_events_in_store = await self.store.have_seen_events( + missing_auth_events + ) + missing_auth_events.difference_update(auth_events_in_store) - await self._get_events_and_persist( - destination=destination, room_id=room_id, events=missing_events - ) + if missing_auth_events: + logger.warning( + "Failed to fetch missing auth events for %s %s", + event_id, + missing_auth_events, + ) - # we need to make sure we re-load from the database to get the rejected - # state correct. - fetched_events.update( - (await self.store.get_events(missing_events, allow_rejected=True)) - ) + remote_state = list(event_map.values()) # check for events which were in the wrong room. # @@ -640,8 +628,8 @@ class FederationHandler(BaseHandler): # auth_events at an event in room A are actually events in room B bad_events = [ - (event_id, event.room_id) - for event_id, event in fetched_events.items() + (event.event_id, event.room_id) + for event in remote_state if event.room_id != room_id ] @@ -658,9 +646,10 @@ class FederationHandler(BaseHandler): room_id, ) - del fetched_events[bad_event_id] + if bad_events: + remote_state = [e for e in remote_state if e.room_id == room_id] - return fetched_events + return remote_state async def _get_state_after_missing_prev_event( self, @@ -963,27 +952,23 @@ class FederationHandler(BaseHandler): # For each edge get the current state. - auth_events = {} state_events = {} events_to_state = {} for e_id in edges: - state, auth = await self._get_state_for_room( + state = await self._get_state_for_room( destination=dest, room_id=room_id, event_id=e_id, ) - auth_events.update({a.event_id: a for a in auth}) - auth_events.update({s.event_id: s for s in state}) state_events.update({s.event_id: s for s in state}) events_to_state[e_id] = state required_auth = { a_id - for event in events - + list(state_events.values()) - + list(auth_events.values()) + for event in events + list(state_events.values()) for a_id in event.auth_event_ids() } + auth_events = await self.store.get_events(required_auth, allow_rejected=True) auth_events.update( {e_id: event_map[e_id] for e_id in required_auth if e_id in event_map} ) |