diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py index 66675d08ae..71316f7d09 100644 --- a/synapse/storage/__init__.py +++ b/synapse/storage/__init__.py @@ -36,6 +36,7 @@ from .engines import PostgresEngine from .event_federation import EventFederationStore from .event_push_actions import EventPushActionsStore from .events import EventsStore +from .events_bg_updates import EventsBackgroundUpdatesStore from .filtering import FilteringStore from .group_server import GroupServerStore from .keys import KeyStore @@ -66,6 +67,7 @@ logger = logging.getLogger(__name__) class DataStore( + EventsBackgroundUpdatesStore, RoomMemberStore, RoomStore, RegistrationStore, diff --git a/synapse/storage/events.py b/synapse/storage/events.py index 418d88b8dc..f9162be9b9 100644 --- a/synapse/storage/events.py +++ b/synapse/storage/events.py @@ -1,6 +1,7 @@ # -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket Ltd -# Copyright 2018 New Vector Ltd +# Copyright 2018-2019 New Vector Ltd +# 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. @@ -219,47 +220,11 @@ class EventsStore( EventsWorkerStore, BackgroundUpdateStore, ): - EVENT_ORIGIN_SERVER_TS_NAME = "event_origin_server_ts" - EVENT_FIELDS_SENDER_URL_UPDATE_NAME = "event_fields_sender_url" - EVENT_DELETE_SOFT_FAILED_EXTREMITIES = "delete_soft_failed_extremities" def __init__(self, db_conn, hs): super(EventsStore, self).__init__(db_conn, hs) - self.register_background_update_handler( - self.EVENT_ORIGIN_SERVER_TS_NAME, self._background_reindex_origin_server_ts - ) - self.register_background_update_handler( - self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, - self._background_reindex_fields_sender, - ) - - self.register_background_index_update( - "event_contains_url_index", - index_name="event_contains_url_index", - table="events", - columns=["room_id", "topological_ordering", "stream_ordering"], - where_clause="contains_url = true AND outlier = false", - ) - - # an event_id index on event_search is useful for the purge_history - # api. Plus it means we get to enforce some integrity with a UNIQUE - # clause - self.register_background_index_update( - "event_search_event_id_idx", - index_name="event_search_event_id_idx", - table="event_search", - columns=["event_id"], - unique=True, - psql_only=True, - ) - - self.register_background_update_handler( - self.EVENT_DELETE_SOFT_FAILED_EXTREMITIES, - self._cleanup_extremities_bg_update, - ) self._event_persist_queue = _EventPeristenceQueue() - self._state_resolution_handler = hs.get_state_resolution_handler() @defer.inlineCallbacks @@ -1585,153 +1550,6 @@ class EventsStore( ret = yield self.runInteraction("count_daily_active_rooms", _count) defer.returnValue(ret) - @defer.inlineCallbacks - def _background_reindex_fields_sender(self, progress, batch_size): - target_min_stream_id = progress["target_min_stream_id_inclusive"] - max_stream_id = progress["max_stream_id_exclusive"] - rows_inserted = progress.get("rows_inserted", 0) - - INSERT_CLUMP_SIZE = 1000 - - def reindex_txn(txn): - sql = ( - "SELECT stream_ordering, event_id, json FROM events" - " INNER JOIN event_json USING (event_id)" - " WHERE ? <= stream_ordering AND stream_ordering < ?" - " ORDER BY stream_ordering DESC" - " LIMIT ?" - ) - - txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size)) - - rows = txn.fetchall() - if not rows: - return 0 - - min_stream_id = rows[-1][0] - - update_rows = [] - for row in rows: - try: - event_id = row[1] - event_json = json.loads(row[2]) - sender = event_json["sender"] - content = event_json["content"] - - contains_url = "url" in content - if contains_url: - contains_url &= isinstance(content["url"], text_type) - except (KeyError, AttributeError): - # If the event is missing a necessary field then - # skip over it. - continue - - update_rows.append((sender, contains_url, event_id)) - - sql = "UPDATE events SET sender = ?, contains_url = ? WHERE event_id = ?" - - for index in range(0, len(update_rows), INSERT_CLUMP_SIZE): - clump = update_rows[index : index + INSERT_CLUMP_SIZE] - txn.executemany(sql, clump) - - progress = { - "target_min_stream_id_inclusive": target_min_stream_id, - "max_stream_id_exclusive": min_stream_id, - "rows_inserted": rows_inserted + len(rows), - } - - self._background_update_progress_txn( - txn, self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, progress - ) - - return len(rows) - - result = yield self.runInteraction( - self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, reindex_txn - ) - - if not result: - yield self._end_background_update(self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME) - - defer.returnValue(result) - - @defer.inlineCallbacks - def _background_reindex_origin_server_ts(self, progress, batch_size): - target_min_stream_id = progress["target_min_stream_id_inclusive"] - max_stream_id = progress["max_stream_id_exclusive"] - rows_inserted = progress.get("rows_inserted", 0) - - INSERT_CLUMP_SIZE = 1000 - - def reindex_search_txn(txn): - sql = ( - "SELECT stream_ordering, event_id FROM events" - " WHERE ? <= stream_ordering AND stream_ordering < ?" - " ORDER BY stream_ordering DESC" - " LIMIT ?" - ) - - txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size)) - - rows = txn.fetchall() - if not rows: - return 0 - - min_stream_id = rows[-1][0] - event_ids = [row[1] for row in rows] - - rows_to_update = [] - - chunks = [event_ids[i : i + 100] for i in range(0, len(event_ids), 100)] - for chunk in chunks: - ev_rows = self._simple_select_many_txn( - txn, - table="event_json", - column="event_id", - iterable=chunk, - retcols=["event_id", "json"], - keyvalues={}, - ) - - for row in ev_rows: - event_id = row["event_id"] - event_json = json.loads(row["json"]) - try: - origin_server_ts = event_json["origin_server_ts"] - except (KeyError, AttributeError): - # If the event is missing a necessary field then - # skip over it. - continue - - rows_to_update.append((origin_server_ts, event_id)) - - sql = "UPDATE events SET origin_server_ts = ? WHERE event_id = ?" - - for index in range(0, len(rows_to_update), INSERT_CLUMP_SIZE): - clump = rows_to_update[index : index + INSERT_CLUMP_SIZE] - txn.executemany(sql, clump) - - progress = { - "target_min_stream_id_inclusive": target_min_stream_id, - "max_stream_id_exclusive": min_stream_id, - "rows_inserted": rows_inserted + len(rows_to_update), - } - - self._background_update_progress_txn( - txn, self.EVENT_ORIGIN_SERVER_TS_NAME, progress - ) - - return len(rows_to_update) - - result = yield self.runInteraction( - self.EVENT_ORIGIN_SERVER_TS_NAME, reindex_search_txn - ) - - if not result: - yield self._end_background_update(self.EVENT_ORIGIN_SERVER_TS_NAME) - - defer.returnValue(result) - def get_current_backfill_token(self): """The current minimum token that backfilled events have reached""" return -self._backfill_id_gen.get_current_token() @@ -2347,191 +2165,6 @@ class EventsStore( get_all_updated_current_state_deltas_txn, ) - @defer.inlineCallbacks - def _cleanup_extremities_bg_update(self, progress, batch_size): - """Background update to clean out extremities that should have been - deleted previously. - - Mainly used to deal with the aftermath of #5269. - """ - - # This works by first copying all existing forward extremities into the - # `_extremities_to_check` table at start up, and then checking each - # event in that table whether we have any descendants that are not - # soft-failed/rejected. If that is the case then we delete that event - # from the forward extremities table. - # - # For efficiency, we do this in batches by recursively pulling out all - # descendants of a batch until we find the non soft-failed/rejected - # events, i.e. the set of descendants whose chain of prev events back - # to the batch of extremities are all soft-failed or rejected. - # Typically, we won't find any such events as extremities will rarely - # have any descendants, but if they do then we should delete those - # extremities. - - def _cleanup_extremities_bg_update_txn(txn): - # The set of extremity event IDs that we're checking this round - original_set = set() - - # A dict[str, set[str]] of event ID to their prev events. - graph = {} - - # The set of descendants of the original set that are not rejected - # nor soft-failed. Ancestors of these events should be removed - # from the forward extremities table. - non_rejected_leaves = set() - - # Set of event IDs that have been soft failed, and for which we - # should check if they have descendants which haven't been soft - # failed. - soft_failed_events_to_lookup = set() - - # First, we get `batch_size` events from the table, pulling out - # their successor events, if any, and their successor events - # rejection status. - txn.execute( - """SELECT prev_event_id, event_id, internal_metadata, - rejections.event_id IS NOT NULL, events.outlier - FROM ( - SELECT event_id AS prev_event_id - FROM _extremities_to_check - LIMIT ? - ) AS f - LEFT JOIN event_edges USING (prev_event_id) - LEFT JOIN events USING (event_id) - LEFT JOIN event_json USING (event_id) - LEFT JOIN rejections USING (event_id) - """, (batch_size,) - ) - - for prev_event_id, event_id, metadata, rejected, outlier in txn: - original_set.add(prev_event_id) - - if not event_id or outlier: - # Common case where the forward extremity doesn't have any - # descendants. - continue - - graph.setdefault(event_id, set()).add(prev_event_id) - - soft_failed = False - if metadata: - soft_failed = json.loads(metadata).get("soft_failed") - - if soft_failed or rejected: - soft_failed_events_to_lookup.add(event_id) - else: - non_rejected_leaves.add(event_id) - - # Now we recursively check all the soft-failed descendants we - # found above in the same way, until we have nothing left to - # check. - while soft_failed_events_to_lookup: - # We only want to do 100 at a time, so we split given list - # into two. - batch = list(soft_failed_events_to_lookup) - to_check, to_defer = batch[:100], batch[100:] - soft_failed_events_to_lookup = set(to_defer) - - sql = """SELECT prev_event_id, event_id, internal_metadata, - rejections.event_id IS NOT NULL - FROM event_edges - INNER JOIN events USING (event_id) - INNER JOIN event_json USING (event_id) - LEFT JOIN rejections USING (event_id) - WHERE - prev_event_id IN (%s) - AND NOT events.outlier - """ % ( - ",".join("?" for _ in to_check), - ) - txn.execute(sql, to_check) - - for prev_event_id, event_id, metadata, rejected in txn: - if event_id in graph: - # Already handled this event previously, but we still - # want to record the edge. - graph[event_id].add(prev_event_id) - continue - - graph[event_id] = {prev_event_id} - - soft_failed = json.loads(metadata).get("soft_failed") - if soft_failed or rejected: - soft_failed_events_to_lookup.add(event_id) - else: - non_rejected_leaves.add(event_id) - - # We have a set of non-soft-failed descendants, so we recurse up - # the graph to find all ancestors and add them to the set of event - # IDs that we can delete from forward extremities table. - to_delete = set() - while non_rejected_leaves: - event_id = non_rejected_leaves.pop() - prev_event_ids = graph.get(event_id, set()) - non_rejected_leaves.update(prev_event_ids) - to_delete.update(prev_event_ids) - - to_delete.intersection_update(original_set) - - deleted = self._simple_delete_many_txn( - txn=txn, - table="event_forward_extremities", - column="event_id", - iterable=to_delete, - keyvalues={}, - ) - - logger.info( - "Deleted %d forward extremities of %d checked, to clean up #5269", - deleted, - len(original_set), - ) - - if deleted: - # We now need to invalidate the caches of these rooms - rows = self._simple_select_many_txn( - txn, - table="events", - column="event_id", - iterable=to_delete, - keyvalues={}, - retcols=("room_id",) - ) - room_ids = set(row["room_id"] for row in rows) - for room_id in room_ids: - txn.call_after( - self.get_latest_event_ids_in_room.invalidate, - (room_id,) - ) - - self._simple_delete_many_txn( - txn=txn, - table="_extremities_to_check", - column="event_id", - iterable=original_set, - keyvalues={}, - ) - - return len(original_set) - - num_handled = yield self.runInteraction( - "_cleanup_extremities_bg_update", _cleanup_extremities_bg_update_txn, - ) - - if not num_handled: - yield self._end_background_update(self.EVENT_DELETE_SOFT_FAILED_EXTREMITIES) - - def _drop_table_txn(txn): - txn.execute("DROP TABLE _extremities_to_check") - - yield self.runInteraction( - "_cleanup_extremities_bg_update_drop_table", - _drop_table_txn, - ) - - defer.returnValue(num_handled) - AllNewEventsResult = namedtuple( "AllNewEventsResult", diff --git a/synapse/storage/events_bg_updates.py b/synapse/storage/events_bg_updates.py new file mode 100644 index 0000000000..2eba106abf --- /dev/null +++ b/synapse/storage/events_bg_updates.py @@ -0,0 +1,401 @@ +# -*- coding: utf-8 -*- +# 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. + +import logging + +from six import text_type + +from canonicaljson import json + +from twisted.internet import defer + +from synapse.storage.background_updates import BackgroundUpdateStore + +logger = logging.getLogger(__name__) + + +class EventsBackgroundUpdatesStore(BackgroundUpdateStore): + + EVENT_ORIGIN_SERVER_TS_NAME = "event_origin_server_ts" + EVENT_FIELDS_SENDER_URL_UPDATE_NAME = "event_fields_sender_url" + EVENT_DELETE_SOFT_FAILED_EXTREMITIES = "delete_soft_failed_extremities" + + def __init__(self, db_conn, hs): + super(EventsBackgroundUpdatesStore, self).__init__(db_conn, hs) + + self.register_background_update_handler( + self.EVENT_ORIGIN_SERVER_TS_NAME, self._background_reindex_origin_server_ts + ) + self.register_background_update_handler( + self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, + self._background_reindex_fields_sender, + ) + + self.register_background_index_update( + "event_contains_url_index", + index_name="event_contains_url_index", + table="events", + columns=["room_id", "topological_ordering", "stream_ordering"], + where_clause="contains_url = true AND outlier = false", + ) + + # an event_id index on event_search is useful for the purge_history + # api. Plus it means we get to enforce some integrity with a UNIQUE + # clause + self.register_background_index_update( + "event_search_event_id_idx", + index_name="event_search_event_id_idx", + table="event_search", + columns=["event_id"], + unique=True, + psql_only=True, + ) + + self.register_background_update_handler( + self.EVENT_DELETE_SOFT_FAILED_EXTREMITIES, + self._cleanup_extremities_bg_update, + ) + + @defer.inlineCallbacks + def _background_reindex_fields_sender(self, progress, batch_size): + target_min_stream_id = progress["target_min_stream_id_inclusive"] + max_stream_id = progress["max_stream_id_exclusive"] + rows_inserted = progress.get("rows_inserted", 0) + + INSERT_CLUMP_SIZE = 1000 + + def reindex_txn(txn): + sql = ( + "SELECT stream_ordering, event_id, json FROM events" + " INNER JOIN event_json USING (event_id)" + " WHERE ? <= stream_ordering AND stream_ordering < ?" + " ORDER BY stream_ordering DESC" + " LIMIT ?" + ) + + txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size)) + + rows = txn.fetchall() + if not rows: + return 0 + + min_stream_id = rows[-1][0] + + update_rows = [] + for row in rows: + try: + event_id = row[1] + event_json = json.loads(row[2]) + sender = event_json["sender"] + content = event_json["content"] + + contains_url = "url" in content + if contains_url: + contains_url &= isinstance(content["url"], text_type) + except (KeyError, AttributeError): + # If the event is missing a necessary field then + # skip over it. + continue + + update_rows.append((sender, contains_url, event_id)) + + sql = "UPDATE events SET sender = ?, contains_url = ? WHERE event_id = ?" + + for index in range(0, len(update_rows), INSERT_CLUMP_SIZE): + clump = update_rows[index : index + INSERT_CLUMP_SIZE] + txn.executemany(sql, clump) + + progress = { + "target_min_stream_id_inclusive": target_min_stream_id, + "max_stream_id_exclusive": min_stream_id, + "rows_inserted": rows_inserted + len(rows), + } + + self._background_update_progress_txn( + txn, self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, progress + ) + + return len(rows) + + result = yield self.runInteraction( + self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME, reindex_txn + ) + + if not result: + yield self._end_background_update(self.EVENT_FIELDS_SENDER_URL_UPDATE_NAME) + + defer.returnValue(result) + + @defer.inlineCallbacks + def _background_reindex_origin_server_ts(self, progress, batch_size): + target_min_stream_id = progress["target_min_stream_id_inclusive"] + max_stream_id = progress["max_stream_id_exclusive"] + rows_inserted = progress.get("rows_inserted", 0) + + INSERT_CLUMP_SIZE = 1000 + + def reindex_search_txn(txn): + sql = ( + "SELECT stream_ordering, event_id FROM events" + " WHERE ? <= stream_ordering AND stream_ordering < ?" + " ORDER BY stream_ordering DESC" + " LIMIT ?" + ) + + txn.execute(sql, (target_min_stream_id, max_stream_id, batch_size)) + + rows = txn.fetchall() + if not rows: + return 0 + + min_stream_id = rows[-1][0] + event_ids = [row[1] for row in rows] + + rows_to_update = [] + + chunks = [event_ids[i : i + 100] for i in range(0, len(event_ids), 100)] + for chunk in chunks: + ev_rows = self._simple_select_many_txn( + txn, + table="event_json", + column="event_id", + iterable=chunk, + retcols=["event_id", "json"], + keyvalues={}, + ) + + for row in ev_rows: + event_id = row["event_id"] + event_json = json.loads(row["json"]) + try: + origin_server_ts = event_json["origin_server_ts"] + except (KeyError, AttributeError): + # If the event is missing a necessary field then + # skip over it. + continue + + rows_to_update.append((origin_server_ts, event_id)) + + sql = "UPDATE events SET origin_server_ts = ? WHERE event_id = ?" + + for index in range(0, len(rows_to_update), INSERT_CLUMP_SIZE): + clump = rows_to_update[index : index + INSERT_CLUMP_SIZE] + txn.executemany(sql, clump) + + progress = { + "target_min_stream_id_inclusive": target_min_stream_id, + "max_stream_id_exclusive": min_stream_id, + "rows_inserted": rows_inserted + len(rows_to_update), + } + + self._background_update_progress_txn( + txn, self.EVENT_ORIGIN_SERVER_TS_NAME, progress + ) + + return len(rows_to_update) + + result = yield self.runInteraction( + self.EVENT_ORIGIN_SERVER_TS_NAME, reindex_search_txn + ) + + if not result: + yield self._end_background_update(self.EVENT_ORIGIN_SERVER_TS_NAME) + + defer.returnValue(result) + + @defer.inlineCallbacks + def _cleanup_extremities_bg_update(self, progress, batch_size): + """Background update to clean out extremities that should have been + deleted previously. + + Mainly used to deal with the aftermath of #5269. + """ + + # This works by first copying all existing forward extremities into the + # `_extremities_to_check` table at start up, and then checking each + # event in that table whether we have any descendants that are not + # soft-failed/rejected. If that is the case then we delete that event + # from the forward extremities table. + # + # For efficiency, we do this in batches by recursively pulling out all + # descendants of a batch until we find the non soft-failed/rejected + # events, i.e. the set of descendants whose chain of prev events back + # to the batch of extremities are all soft-failed or rejected. + # Typically, we won't find any such events as extremities will rarely + # have any descendants, but if they do then we should delete those + # extremities. + + def _cleanup_extremities_bg_update_txn(txn): + # The set of extremity event IDs that we're checking this round + original_set = set() + + # A dict[str, set[str]] of event ID to their prev events. + graph = {} + + # The set of descendants of the original set that are not rejected + # nor soft-failed. Ancestors of these events should be removed + # from the forward extremities table. + non_rejected_leaves = set() + + # Set of event IDs that have been soft failed, and for which we + # should check if they have descendants which haven't been soft + # failed. + soft_failed_events_to_lookup = set() + + # First, we get `batch_size` events from the table, pulling out + # their successor events, if any, and their successor events + # rejection status. + txn.execute( + """SELECT prev_event_id, event_id, internal_metadata, + rejections.event_id IS NOT NULL, events.outlier + FROM ( + SELECT event_id AS prev_event_id + FROM _extremities_to_check + LIMIT ? + ) AS f + LEFT JOIN event_edges USING (prev_event_id) + LEFT JOIN events USING (event_id) + LEFT JOIN event_json USING (event_id) + LEFT JOIN rejections USING (event_id) + """, (batch_size,) + ) + + for prev_event_id, event_id, metadata, rejected, outlier in txn: + original_set.add(prev_event_id) + + if not event_id or outlier: + # Common case where the forward extremity doesn't have any + # descendants. + continue + + graph.setdefault(event_id, set()).add(prev_event_id) + + soft_failed = False + if metadata: + soft_failed = json.loads(metadata).get("soft_failed") + + if soft_failed or rejected: + soft_failed_events_to_lookup.add(event_id) + else: + non_rejected_leaves.add(event_id) + + # Now we recursively check all the soft-failed descendants we + # found above in the same way, until we have nothing left to + # check. + while soft_failed_events_to_lookup: + # We only want to do 100 at a time, so we split given list + # into two. + batch = list(soft_failed_events_to_lookup) + to_check, to_defer = batch[:100], batch[100:] + soft_failed_events_to_lookup = set(to_defer) + + sql = """SELECT prev_event_id, event_id, internal_metadata, + rejections.event_id IS NOT NULL + FROM event_edges + INNER JOIN events USING (event_id) + INNER JOIN event_json USING (event_id) + LEFT JOIN rejections USING (event_id) + WHERE + prev_event_id IN (%s) + AND NOT events.outlier + """ % ( + ",".join("?" for _ in to_check), + ) + txn.execute(sql, to_check) + + for prev_event_id, event_id, metadata, rejected in txn: + if event_id in graph: + # Already handled this event previously, but we still + # want to record the edge. + graph[event_id].add(prev_event_id) + continue + + graph[event_id] = {prev_event_id} + + soft_failed = json.loads(metadata).get("soft_failed") + if soft_failed or rejected: + soft_failed_events_to_lookup.add(event_id) + else: + non_rejected_leaves.add(event_id) + + # We have a set of non-soft-failed descendants, so we recurse up + # the graph to find all ancestors and add them to the set of event + # IDs that we can delete from forward extremities table. + to_delete = set() + while non_rejected_leaves: + event_id = non_rejected_leaves.pop() + prev_event_ids = graph.get(event_id, set()) + non_rejected_leaves.update(prev_event_ids) + to_delete.update(prev_event_ids) + + to_delete.intersection_update(original_set) + + deleted = self._simple_delete_many_txn( + txn=txn, + table="event_forward_extremities", + column="event_id", + iterable=to_delete, + keyvalues={}, + ) + + logger.info( + "Deleted %d forward extremities of %d checked, to clean up #5269", + deleted, + len(original_set), + ) + + if deleted: + # We now need to invalidate the caches of these rooms + rows = self._simple_select_many_txn( + txn, + table="events", + column="event_id", + iterable=to_delete, + keyvalues={}, + retcols=("room_id",) + ) + room_ids = set(row["room_id"] for row in rows) + for room_id in room_ids: + txn.call_after( + self.get_latest_event_ids_in_room.invalidate, + (room_id,) + ) + + self._simple_delete_many_txn( + txn=txn, + table="_extremities_to_check", + column="event_id", + iterable=original_set, + keyvalues={}, + ) + + return len(original_set) + + num_handled = yield self.runInteraction( + "_cleanup_extremities_bg_update", _cleanup_extremities_bg_update_txn, + ) + + if not num_handled: + yield self._end_background_update(self.EVENT_DELETE_SOFT_FAILED_EXTREMITIES) + + def _drop_table_txn(txn): + txn.execute("DROP TABLE _extremities_to_check") + + yield self.runInteraction( + "_cleanup_extremities_bg_update_drop_table", + _drop_table_txn, + ) + + defer.returnValue(num_handled)