From 6de09e07a6f7d043589205c25594852900a6626b Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 17 Jul 2019 15:33:37 +0100 Subject: [PATCH 1/7] Add membership column to current_state_events table. It turns out that doing a join is surprisingly expensive for the DB to do when room_membership table is larger than the disk cache. --- synapse/storage/events.py | 26 ++++++++++--------- synapse/storage/prepare_database.py | 2 +- synapse/storage/roommember.py | 6 ++--- .../56/current_state_events_membership.sql | 19 ++++++++++++++ synapse/storage/user_directory.py | 8 +++--- 5 files changed, 41 insertions(+), 20 deletions(-) create mode 100644 synapse/storage/schema/delta/56/current_state_events_membership.sql diff --git a/synapse/storage/events.py b/synapse/storage/events.py index b486ca50e..b70457bfc 100644 --- a/synapse/storage/events.py +++ b/synapse/storage/events.py @@ -918,8 +918,6 @@ class EventsStore( min_stream_order = events_and_contexts[0][0].internal_metadata.stream_ordering max_stream_order = events_and_contexts[-1][0].internal_metadata.stream_ordering - self._update_current_state_txn(txn, state_delta_for_room, min_stream_order) - self._update_forward_extremities_txn( txn, new_forward_extremities=new_forward_extremeties, @@ -993,6 +991,10 @@ class EventsStore( backfilled=backfilled, ) + # We call this last as it assumes we've inserted the events into + # room_memberships, where applicable. + self._update_current_state_txn(txn, state_delta_for_room, min_stream_order) + def _update_current_state_txn(self, txn, state_delta_by_room, stream_id): for room_id, current_state_tuple in iteritems(state_delta_by_room): to_delete, to_insert = current_state_tuple @@ -1062,16 +1064,16 @@ class EventsStore( ), ) - self._simple_insert_many_txn( - txn, - table="current_state_events", - values=[ - { - "event_id": ev_id, - "room_id": room_id, - "type": key[0], - "state_key": key[1], - } + # We include the membership in the current state table, hence we do + # a lookup when we insert. This assumes that all events have already + # been inserted into room_memberships. + txn.executemany( + """INSERT INTO current_state_events + (room_id, type, state_key, event_id, membership) + VALUES (?, ?, ?, ?, (SELECT membership FROM room_memberships WHERE event_id = ?)) + """, + [ + (room_id, key[0], key[1], ev_id, ev_id) for key, ev_id in iteritems(to_insert) ], ) diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py index 7c4e1dc7e..d20eacda5 100644 --- a/synapse/storage/prepare_database.py +++ b/synapse/storage/prepare_database.py @@ -27,7 +27,7 @@ logger = logging.getLogger(__name__) # Remember to update this number every time a change is made to database # schema files, so the users will be informed on server restarts. -SCHEMA_VERSION = 55 +SCHEMA_VERSION = 56 dir_path = os.path.abspath(os.path.dirname(__file__)) diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py index 32cfd010a..4946afe63 100644 --- a/synapse/storage/roommember.py +++ b/synapse/storage/roommember.py @@ -224,7 +224,7 @@ class RoomMemberWorkerStore(EventsWorkerStore): results = [] if membership_list: where_clause = "user_id = ? AND (%s) AND forgotten = 0" % ( - " OR ".join(["membership = ?" for _ in membership_list]), + " OR ".join(["m.membership = ?" for _ in membership_list]), ) args = [user_id] @@ -453,8 +453,8 @@ class RoomMemberWorkerStore(EventsWorkerStore): sql = """ SELECT state_key FROM current_state_events AS c - INNER JOIN room_memberships USING (event_id) - WHERE membership = 'join' + INNER JOIN room_memberships AS m USING (event_id) + WHERE m.membership = 'join' AND type = 'm.room.member' AND c.room_id = ? AND state_key LIKE ? diff --git a/synapse/storage/schema/delta/56/current_state_events_membership.sql b/synapse/storage/schema/delta/56/current_state_events_membership.sql new file mode 100644 index 000000000..5c754651c --- /dev/null +++ b/synapse/storage/schema/delta/56/current_state_events_membership.sql @@ -0,0 +1,19 @@ +/* Copyright 2019 The Matrix.org Foundation C.I.C. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +-- We add membership to current state so that we don't need to join against +-- room_memberships, which can be surprisingly costly (we do such queries +-- very frequently). +ALTER TABLE current_state_events ADD membership TEXT; diff --git a/synapse/storage/user_directory.py b/synapse/storage/user_directory.py index 83466e25d..7fd16fe65 100644 --- a/synapse/storage/user_directory.py +++ b/synapse/storage/user_directory.py @@ -618,15 +618,15 @@ class UserDirectoryStore(StateDeltasStore, BackgroundUpdateStore): sql = """ SELECT room_id FROM ( SELECT c.room_id FROM current_state_events AS c - INNER JOIN room_memberships USING (event_id) + INNER JOIN room_memberships AS m USING (event_id) WHERE type = 'm.room.member' - AND membership = 'join' + AND m.membership = 'join' AND state_key = ? ) AS f1 INNER JOIN ( SELECT c.room_id FROM current_state_events AS c - INNER JOIN room_memberships USING (event_id) + INNER JOIN room_memberships AS m USING (event_id) WHERE type = 'm.room.member' - AND membership = 'join' + AND m.membership = 'join' AND state_key = ? ) f2 USING (room_id) """ From c618a5d348295b69885953cd1970fe1f339a4e9f Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 17 Jul 2019 15:50:08 +0100 Subject: [PATCH 2/7] Add background update for current_state_events.membership column --- synapse/storage/roommember.py | 51 +++++++++++++++++++ .../56/current_state_events_membership.sql | 3 ++ 2 files changed, 54 insertions(+) diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py index 4946afe63..275fef1f6 100644 --- a/synapse/storage/roommember.py +++ b/synapse/storage/roommember.py @@ -53,6 +53,7 @@ ProfileInfo = namedtuple("ProfileInfo", ("avatar_url", "display_name")) MemberSummary = namedtuple("MemberSummary", ("members", "count")) _MEMBERSHIP_PROFILE_UPDATE_NAME = "room_membership_profile_update" +_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME = "current_state_events_membership" class RoomMemberWorkerStore(EventsWorkerStore): @@ -602,6 +603,10 @@ class RoomMemberStore(RoomMemberWorkerStore): self.register_background_update_handler( _MEMBERSHIP_PROFILE_UPDATE_NAME, self._background_add_membership_profile ) + self.register_background_update_handler( + _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME, + self._background_current_state_membership, + ) def _store_room_members_txn(self, txn, events, backfilled): """Store a room member in the database. @@ -781,6 +786,52 @@ class RoomMemberStore(RoomMemberWorkerStore): defer.returnValue(result) + @defer.inlineCallbacks + def _background_current_state_membership(self, progress, batch_size): + """Update the new membership column on current_state_events. + """ + + if "rooms" not in progress: + rooms = yield self._simple_select_onecol( + table="current_state_events", + keyvalues={}, + retcol="DISTINCT room_id", + desc="_background_current_state_membership_get_rooms", + ) + progress["rooms"] = rooms + + rooms = progress["rooms"] + + def _background_current_state_membership_txn(txn): + processed = 0 + while rooms and processed < batch_size: + sql = """ + UPDATE current_state_events AS c + SET membership = ( + SELECT membership FROM room_memberships + WHERE event_id = c.event_id + ) + WHERE room_id = ? + """ + txn.execute(sql, (rooms.pop(),)) + processed += txn.rowcount + + self._background_update_progress_txn( + txn, _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME, progress + ) + + return processed + + result = yield self.runInteraction( + "_background_current_state_membership_update", + _background_current_state_membership_txn, + ) + + if not rooms: + yield self._end_background_update(_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME) + + defer.returnValue(result) + class _JoinedHostsCache(object): """Cache for joined hosts in a room that is optimised to handle updates diff --git a/synapse/storage/schema/delta/56/current_state_events_membership.sql b/synapse/storage/schema/delta/56/current_state_events_membership.sql index 5c754651c..ec7ad5bae 100644 --- a/synapse/storage/schema/delta/56/current_state_events_membership.sql +++ b/synapse/storage/schema/delta/56/current_state_events_membership.sql @@ -17,3 +17,6 @@ -- room_memberships, which can be surprisingly costly (we do such queries -- very frequently). ALTER TABLE current_state_events ADD membership TEXT; + +INSERT INTO background_updates (update_name, progress_json) VALUES + ('current_state_events_membership', '{}'); From 059d8c1a4e720f9a0a179f7109f38302885bc9a4 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 17 Jul 2019 16:09:14 +0100 Subject: [PATCH 3/7] Track if current_state_events.membership is up to date --- synapse/storage/roommember.py | 45 +++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py index 275fef1f6..f913abf8d 100644 --- a/synapse/storage/roommember.py +++ b/synapse/storage/roommember.py @@ -24,6 +24,8 @@ from canonicaljson import json from twisted.internet import defer from synapse.api.constants import EventTypes, Membership +from synapse.metrics.background_process_metrics import run_as_background_process +from synapse.storage._base import LoggingTransaction from synapse.storage.events_worker import EventsWorkerStore from synapse.types import get_domain_from_id from synapse.util.async_helpers import Linearizer @@ -57,6 +59,49 @@ _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME = "current_state_events_membership" class RoomMemberWorkerStore(EventsWorkerStore): + def __init__(self, db_conn, hs): + super(RoomMemberWorkerStore, self).__init__(db_conn, hs) + + # Is the current_state_events.membership up to date? Or is the + # background update still running? + self._current_state_events_membership_up_to_date = False + + txn = LoggingTransaction( + db_conn.cursor(), + name="_check_safe_current_state_events_membership_updated", + database_engine=self.database_engine, + after_callbacks=[], + exception_callbacks=[], + ) + self._check_safe_current_state_events_membership_updated_txn(txn) + txn.close() + + def _check_safe_current_state_events_membership_updated_txn(self, txn): + """Checks if it is safe to assume the new current_state_events + membership column is up to date + """ + + pending_update = self._simple_select_one_txn( + txn, + table="background_updates", + keyvalues={"update_name": _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME}, + retcols=["update_name"], + allow_none=True, + ) + + self._current_state_events_membership_up_to_date = not pending_update + + # If the update is still running, reschedule to run. + if pending_update: + self._clock.call_later( + 15.0, + run_as_background_process, + "_check_safe_current_state_events_membership_updated", + self.runInteraction, + "_check_safe_current_state_events_membership_updated", + self._check_safe_current_state_events_membership_updated_txn, + ) + @cachedInlineCallbacks(max_entries=100000, iterable=True, cache_context=True) def get_hosts_in_room(self, room_id, cache_context): """Returns the set of all hosts currently in the room From 8e1ada9e6fdebe0cedaf39794a326196a9bd90d0 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 17 Jul 2019 16:17:17 +0100 Subject: [PATCH 4/7] Use the current_state_events.membership column --- synapse/storage/roommember.py | 54 ++++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 17 deletions(-) diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py index f913abf8d..6541da3b8 100644 --- a/synapse/storage/roommember.py +++ b/synapse/storage/roommember.py @@ -115,14 +115,23 @@ class RoomMemberWorkerStore(EventsWorkerStore): @cached(max_entries=100000, iterable=True) def get_users_in_room(self, room_id): def f(txn): - sql = ( - "SELECT m.user_id FROM room_memberships as m" - " INNER JOIN current_state_events as c" - " ON m.event_id = c.event_id " - " AND m.room_id = c.room_id " - " AND m.user_id = c.state_key" - " WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?" - ) + # If we can assume current_state_events.membership is up to date + # then we can avoid a join, which is a Very Good Thing given how + # frequently this function gets called. + if self._current_state_events_membership_up_to_date: + sql = """ + SELECT state_key FROM current_state_events + WHERE type = 'm.room.member' AND room_id = ? AND membership = ? + """ + else: + sql = """ + SELECT state_key FROM room_memberships as m + INNER JOIN current_state_events as c + ON m.event_id = c.event_id + AND m.room_id = c.room_id + AND m.user_id = c.state_key + WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ? + """ txn.execute(sql, (room_id, Membership.JOIN)) return [to_ascii(r[0]) for r in txn] @@ -144,15 +153,26 @@ class RoomMemberWorkerStore(EventsWorkerStore): # first get counts. # We do this all in one transaction to keep the cache small. # FIXME: get rid of this when we have room_stats - sql = """ - SELECT count(*), m.membership FROM room_memberships as m - INNER JOIN current_state_events as c - ON m.event_id = c.event_id - AND m.room_id = c.room_id - AND m.user_id = c.state_key - WHERE c.type = 'm.room.member' AND c.room_id = ? - GROUP BY m.membership - """ + + # If we can assume current_state_events.membership is up to date + # then we can avoid a join, which is a Very Good Thing given how + # frequently this function gets called. + if self._current_state_events_membership_up_to_date: + sql = """ + SELECT count(*), membership FROM current_state_events + WHERE type = 'm.room.member' AND room_id = ? + GROUP BY membership + """ + else: + sql = """ + SELECT count(*), m.membership FROM room_memberships as m + INNER JOIN current_state_events as c + ON m.event_id = c.event_id + AND m.room_id = c.room_id + AND m.user_id = c.state_key + WHERE c.type = 'm.room.member' AND c.room_id = ? + GROUP BY m.membership + """ txn.execute(sql, (room_id,)) res = {} From 89c885909aeb4591756c011f5eb339d7301591d5 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 17 Jul 2019 16:22:26 +0100 Subject: [PATCH 5/7] Newsfile --- changelog.d/5706.misc | 1 + 1 file changed, 1 insertion(+) create mode 100644 changelog.d/5706.misc diff --git a/changelog.d/5706.misc b/changelog.d/5706.misc new file mode 100644 index 000000000..5e15dfd5f --- /dev/null +++ b/changelog.d/5706.misc @@ -0,0 +1 @@ +Reduce database IO usage by optimising queries for current membership. From ebc5ed1296c433e97d4dcf1c8a5fc1477506e84e Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Fri, 19 Jul 2019 13:29:02 +0100 Subject: [PATCH 6/7] Update comment for new column --- .../schema/delta/56/current_state_events_membership.sql | 3 +++ 1 file changed, 3 insertions(+) diff --git a/synapse/storage/schema/delta/56/current_state_events_membership.sql b/synapse/storage/schema/delta/56/current_state_events_membership.sql index ec7ad5bae..b2e08cd85 100644 --- a/synapse/storage/schema/delta/56/current_state_events_membership.sql +++ b/synapse/storage/schema/delta/56/current_state_events_membership.sql @@ -16,6 +16,9 @@ -- We add membership to current state so that we don't need to join against -- room_memberships, which can be surprisingly costly (we do such queries -- very frequently). +-- This will be null for non-membership events and the content.membership key +-- for membership events. (Will also be null for membership events until the +-- background update job has finished). ALTER TABLE current_state_events ADD membership TEXT; INSERT INTO background_updates (update_name, progress_json) VALUES From bd2e1a2aa86b81d232f9d14d2a82a04de4b1643d Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Fri, 19 Jul 2019 13:36:04 +0100 Subject: [PATCH 7/7] LoggingTransaction accepts None for callback lists. Its a bit disingenuousto give LoggingTransaction lists to append callbacks to if we're not going to run the callbacks. --- synapse/storage/_base.py | 18 ++++++++++++++++-- synapse/storage/event_push_actions.py | 2 -- synapse/storage/roommember.py | 2 -- 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py index 2f940dbae..a7c93efa4 100644 --- a/synapse/storage/_base.py +++ b/synapse/storage/_base.py @@ -86,7 +86,21 @@ _CURRENT_STATE_CACHE_NAME = "cs_cache_fake" class LoggingTransaction(object): """An object that almost-transparently proxies for the 'txn' object passed to the constructor. Adds logging and metrics to the .execute() - method.""" + method. + + Args: + txn: The database transcation object to wrap. + name (str): The name of this transactions for logging. + database_engine (Sqlite3Engine|PostgresEngine) + after_callbacks(list|None): A list that callbacks will be appended to + that have been added by `call_after` which should be run on + successful completion of the transaction. None indicates that no + callbacks should be allowed to be scheduled to run. + exception_callbacks(list|None): A list that callbacks will be appended + to that have been added by `call_on_exception` which should be run + if transaction ends with an error. None indicates that no callbacks + should be allowed to be scheduled to run. + """ __slots__ = [ "txn", @@ -97,7 +111,7 @@ class LoggingTransaction(object): ] def __init__( - self, txn, name, database_engine, after_callbacks, exception_callbacks + self, txn, name, database_engine, after_callbacks=None, exception_callbacks=None ): object.__setattr__(self, "txn", txn) object.__setattr__(self, "name", name) diff --git a/synapse/storage/event_push_actions.py b/synapse/storage/event_push_actions.py index eca77069f..dcfb67e02 100644 --- a/synapse/storage/event_push_actions.py +++ b/synapse/storage/event_push_actions.py @@ -79,8 +79,6 @@ class EventPushActionsWorkerStore(SQLBaseStore): db_conn.cursor(), name="_find_stream_orderings_for_times_txn", database_engine=self.database_engine, - after_callbacks=[], - exception_callbacks=[], ) self._find_stream_orderings_for_times_txn(cur) cur.close() diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py index 6541da3b8..257bcdb2f 100644 --- a/synapse/storage/roommember.py +++ b/synapse/storage/roommember.py @@ -70,8 +70,6 @@ class RoomMemberWorkerStore(EventsWorkerStore): db_conn.cursor(), name="_check_safe_current_state_events_membership_updated", database_engine=self.database_engine, - after_callbacks=[], - exception_callbacks=[], ) self._check_safe_current_state_events_membership_updated_txn(txn) txn.close()