Merge pull request #5294 from matrix-org/erikj/speed_up_room_stats

Speed up room stats background update

1 files changed, 66 insertions, 64 deletions

diff --git a/synapse/storage/stats.py b/synapse/storage/stats.py
index eb0ced5b5e..1c0b183a56 100644
--- a/synapse/storage/stats.py
+++ b/synapse/storage/stats.py
@@ -18,6 +18,7 @@ import logging
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
+from synapse.storage.prepare_database import get_statements
 from synapse.storage.state_deltas import StateDeltasStore
 from synapse.util.caches.descriptors import cached
 
@@ -69,12 +70,25 @@ class StatsStore(StateDeltasStore):
 
         # Get all the rooms that we want to process.
         def _make_staging_area(txn):
-            sql = (
-                "CREATE TABLE IF NOT EXISTS "
-                + TEMP_TABLE
-                + "_rooms(room_id TEXT NOT NULL, events BIGINT NOT NULL)"
-            )
-            txn.execute(sql)
+            # Create the temporary tables
+            stmts = get_statements("""
+                -- We just recreate the table, we'll be reinserting the
+                -- correct entries again later anyway.
+                DROP TABLE IF EXISTS {temp}_rooms;
+
+                CREATE TABLE IF NOT EXISTS {temp}_rooms(
+                    room_id TEXT NOT NULL,
+                    events BIGINT NOT NULL
+                );
+
+                CREATE INDEX {temp}_rooms_events
+                    ON {temp}_rooms(events);
+                CREATE INDEX {temp}_rooms_id
+                    ON {temp}_rooms(room_id);
+            """.format(temp=TEMP_TABLE).splitlines())
+
+            for statement in stmts:
+                txn.execute(statement)
 
             sql = (
                 "CREATE TABLE IF NOT EXISTS "
@@ -83,15 +97,16 @@ class StatsStore(StateDeltasStore):
             )
             txn.execute(sql)
 
-            # Get rooms we want to process from the database
+            # Get rooms we want to process from the database, only adding
+            # those that we haven't (i.e. those not in room_stats_earliest_token)
             sql = """
-                SELECT room_id, count(*) FROM current_state_events
-                GROUP BY room_id
-            """
+                INSERT INTO %s_rooms (room_id, events)
+                SELECT c.room_id, count(*) FROM current_state_events AS c
+                LEFT JOIN room_stats_earliest_token AS t USING (room_id)
+                WHERE t.room_id IS NULL
+                GROUP BY c.room_id
+            """ % (TEMP_TABLE,)
             txn.execute(sql)
-            rooms = [{"room_id": x[0], "events": x[1]} for x in txn.fetchall()]
-            self._simple_insert_many_txn(txn, TEMP_TABLE + "_rooms", rooms)
-            del rooms
 
         new_pos = yield self.get_max_stream_id_in_current_state_deltas()
         yield self.runInteraction("populate_stats_temp_build", _make_staging_area)
@@ -179,46 +194,39 @@ class StatsStore(StateDeltasStore):
 
             current_state_ids = yield self.get_current_state_ids(room_id)
 
-            join_rules = yield self.get_event(
-                current_state_ids.get((EventTypes.JoinRules, "")), allow_none=True
-            )
-            history_visibility = yield self.get_event(
-                current_state_ids.get((EventTypes.RoomHistoryVisibility, "")),
-                allow_none=True,
-            )
-            encryption = yield self.get_event(
-                current_state_ids.get((EventTypes.RoomEncryption, "")), allow_none=True
-            )
-            name = yield self.get_event(
-                current_state_ids.get((EventTypes.Name, "")), allow_none=True
-            )
-            topic = yield self.get_event(
-                current_state_ids.get((EventTypes.Topic, "")), allow_none=True
-            )
-            avatar = yield self.get_event(
-                current_state_ids.get((EventTypes.RoomAvatar, "")), allow_none=True
+            join_rules_id = current_state_ids.get((EventTypes.JoinRules, ""))
+            history_visibility_id = current_state_ids.get(
+                (EventTypes.RoomHistoryVisibility, "")
             )
-            canonical_alias = yield self.get_event(
-                current_state_ids.get((EventTypes.CanonicalAlias, "")), allow_none=True
-            )
-
-            def _or_none(x, arg):
-                if x:
-                    return x.content.get(arg)
+            encryption_id = current_state_ids.get((EventTypes.RoomEncryption, ""))
+            name_id = current_state_ids.get((EventTypes.Name, ""))
+            topic_id = current_state_ids.get((EventTypes.Topic, ""))
+            avatar_id = current_state_ids.get((EventTypes.RoomAvatar, ""))
+            canonical_alias_id = current_state_ids.get((EventTypes.CanonicalAlias, ""))
+
+            state_events = yield self.get_events([
+                join_rules_id, history_visibility_id, encryption_id, name_id,
+                topic_id, avatar_id, canonical_alias_id,
+            ])
+
+            def _get_or_none(event_id, arg):
+                event = state_events.get(event_id)
+                if event:
+                    return event.content.get(arg)
                 return None
 
             yield self.update_room_state(
                 room_id,
                 {
-                    "join_rules": _or_none(join_rules, "join_rule"),
-                    "history_visibility": _or_none(
-                        history_visibility, "history_visibility"
+                    "join_rules": _get_or_none(join_rules_id, "join_rule"),
+                    "history_visibility": _get_or_none(
+                        history_visibility_id, "history_visibility"
                     ),
-                    "encryption": _or_none(encryption, "algorithm"),
-                    "name": _or_none(name, "name"),
-                    "topic": _or_none(topic, "topic"),
-                    "avatar": _or_none(avatar, "url"),
-                    "canonical_alias": _or_none(canonical_alias, "alias"),
+                    "encryption": _get_or_none(encryption_id, "algorithm"),
+                    "name": _get_or_none(name_id, "name"),
+                    "topic": _get_or_none(topic_id, "topic"),
+                    "avatar": _get_or_none(avatar_id, "url"),
+                    "canonical_alias": _get_or_none(canonical_alias_id, "alias"),
                 },
             )
 
@@ -233,18 +241,9 @@ class StatsStore(StateDeltasStore):
                 current_token = self._get_max_stream_id_in_current_state_deltas_txn(txn)
 
                 current_state_events = len(current_state_ids)
-                joined_members = self._get_user_count_in_room_txn(
-                    txn, room_id, Membership.JOIN
-                )
-                invited_members = self._get_user_count_in_room_txn(
-                    txn, room_id, Membership.INVITE
-                )
-                left_members = self._get_user_count_in_room_txn(
-                    txn, room_id, Membership.LEAVE
-                )
-                banned_members = self._get_user_count_in_room_txn(
-                    txn, room_id, Membership.BAN
-                )
+
+                membership_counts = self._get_user_counts_in_room_txn(txn, room_id)
+
                 total_state_events = self._get_total_state_event_counts_txn(
                     txn, room_id
                 )
@@ -257,10 +256,10 @@ class StatsStore(StateDeltasStore):
                     {
                         "bucket_size": self.stats_bucket_size,
                         "current_state_events": current_state_events,
-                        "joined_members": joined_members,
-                        "invited_members": invited_members,
-                        "left_members": left_members,
-                        "banned_members": banned_members,
+                        "joined_members": membership_counts.get(Membership.JOIN, 0),
+                        "invited_members": membership_counts.get(Membership.INVITE, 0),
+                        "left_members": membership_counts.get(Membership.LEAVE, 0),
+                        "banned_members": membership_counts.get(Membership.BAN, 0),
                         "state_events": total_state_events,
                     },
                 )
@@ -270,10 +269,13 @@ class StatsStore(StateDeltasStore):
                     {"room_id": room_id, "token": current_token},
                 )
 
+                # We've finished a room. Delete it from the table.
+                self._simple_delete_one_txn(
+                    txn, TEMP_TABLE + "_rooms", {"room_id": room_id},
+                )
+
             yield self.runInteraction("update_room_stats", _fetch_data)
 
-            # We've finished a room. Delete it from the table.
-            yield self._simple_delete_one(TEMP_TABLE + "_rooms", {"room_id": room_id})
             # Update the remaining counter.
             progress["remaining"] -= 1
             yield self.runInteraction(