diff --git a/changelog.d/3584.misc b/changelog.d/3584.misc new file mode 100644 index 0000000000..2374dc0c44 --- /dev/null +++ b/changelog.d/3584.misc @@ -0,0 +1 @@ +Lazily load state on master process when using workers to reduce DB consumption diff --git a/synapse/events/snapshot.py b/synapse/events/snapshot.py index a59064b416..189212b0fa 100644 --- a/synapse/events/snapshot.py +++ b/synapse/events/snapshot.py @@ -163,6 +163,9 @@ class EventContext(object): context._prev_state_id = input["prev_state_id"] context._event_type = input["event_type"] context._event_state_key = input["event_state_key"] + + context._current_state_ids = None + context._prev_state_ids = None context._fetching_state_deferred = None context.state_group = input["state_group"] @@ -214,6 +217,17 @@ class EventContext(object): defer.returnValue(self._prev_state_ids) + def get_cached_current_state_ids(self): + """Gets the current state IDs if we have them already cached. + + Returns: + dict[(str, str), str]|None: Returns None if we haven't cached the + state or if state_group is None, which happens when the associated + event is an outlier. + """ + + return self._current_state_ids + @defer.inlineCallbacks def _fill_out_state(self, store): """Called to populate the _current_state_ids and _prev_state_ids diff --git a/synapse/storage/events.py b/synapse/storage/events.py index bf4f3ee92a..c2910094d0 100644 --- a/synapse/storage/events.py +++ b/synapse/storage/events.py @@ -549,7 +549,12 @@ class EventsStore(EventsWorkerStore): if ctx.state_group in state_groups_map: continue - state_groups_map[ctx.state_group] = yield ctx.get_current_state_ids(self) + # We're only interested in pulling out state that has already + # been cached in the context. We'll pull stuff out of the DB later + # if necessary. + current_state_ids = ctx.get_cached_current_state_ids() + if current_state_ids is not None: + state_groups_map[ctx.state_group] = current_state_ids # We need to map the event_ids to their state groups. First, let's # check if the event is one we're persisting, in which case we can