Persist events in parrellel if possible

synapse/storage/events.py

@@ -20,6 +20,7 @@ from twisted.internet import defer, reactor
 from synapse.events import FrozenEvent, USE_FROZEN_DICTS
 from synapse.events.utils import prune_event
 
+from synapse.util import unwrapFirstError
 from synapse.util.logcontext import preserve_context_over_deferred
 from synapse.util.logutils import log_function
 from synapse.api.constants import EventTypes
@@ -75,6 +76,8 @@ class EventsStore(SQLBaseStore):
                 for x in xrange(0, len(events_and_contexts), 100)
             ]
 
+            if is_new_state:
+                # If is_new_state then we have to do chunks in order
                 for chunk in chunks:
                     yield self.runInteraction(
                         "persist_events",
@@ -83,6 +86,21 @@ class EventsStore(SQLBaseStore):
                         backfilled=backfilled,
                         is_new_state=is_new_state,
                     )
+            else:
+                # Otherwise, do them sequentially
+                yield defer.gatherResults(
+                    [
+                        self.runInteraction(
+                            "persist_events",
+                            self._persist_events_txn,
+                            events_and_contexts=chunk,
+                            backfilled=backfilled,
+                            is_new_state=is_new_state,
+                        )
+                        for chunk in chunks
+                    ],
+                    consumeErrors=True,
+                ).addErrback(unwrapFirstError)
 
     @defer.inlineCallbacks
     @log_function