diff options
| -rw-r--r-- | synapse/storage/background_updates.py | 83 |
1 files changed, 53 insertions, 30 deletions
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py index 813ad59e56..d4cf0fc59b 100644 --- a/synapse/storage/background_updates.py +++ b/synapse/storage/background_updates.py @@ -228,46 +228,69 @@ class BackgroundUpdateStore(SQLBaseStore): columns (list[str]): columns/expressions to include in index """ - # if this is postgres, we add the indexes concurrently. Otherwise - # we fall back to doing it inline - if isinstance(self.database_engine, engines.PostgresEngine): - conc = True - else: - conc = False - # We don't use partial indices on SQLite as it wasn't introduced - # until 3.8, and wheezy has 3.7 - where_clause = None - - sql = ( - "CREATE INDEX %(conc)s %(name)s ON %(table)s (%(columns)s)" - " %(where_clause)s" - ) % { - "conc": "CONCURRENTLY" if conc else "", - "name": index_name, - "table": table, - "columns": ", ".join(columns), - "where_clause": "WHERE " + where_clause if where_clause else "" - } - - def create_index_concurrently(conn): + def create_index_psql(conn): conn.rollback() # postgres insists on autocommit for the index conn.set_session(autocommit=True) - c = conn.cursor() - c.execute(sql) - conn.set_session(autocommit=False) - def create_index(conn): + try: + c = conn.cursor() + + # If a previous attempt to create the index was interrupted, + # we may already have a half-built index. Let's just drop it + # before trying to create it again. + + sql = "DROP INDEX IF EXISTS %s" % (index_name,) + logger.debug("[SQL] %s", sql) + c.execute(sql) + + sql = ( + "CREATE INDEX CONCURRENTLY %(name)s ON %(table)s" + " (%(columns)s) %(where_clause)s" + ) % { + "name": index_name, + "table": table, + "columns": ", ".join(columns), + "where_clause": "WHERE " + where_clause if where_clause else "" + } + logger.debug("[SQL] %s", sql) + c.execute(sql) + finally: + conn.set_session(autocommit=False) + + def create_index_sqlite(conn): + # Sqlite doesn't support concurrent creation of indexes. + # + # We don't use partial indices on SQLite as it wasn't introduced + # until 3.8, and wheezy has 3.7 + # + # We assume that sqlite doesn't give us invalid indices; however + # we may still end up with the index existing but the + # background_updates not having been recorded if synapse got shut + # down at the wrong moment - hance we use IF NOT EXISTS. (SQLite + # has supported CREATE TABLE|INDEX IF NOT EXISTS since 3.3.0.) + sql = ( + "CREATE INDEX IF NOT EXISTS %(name)s ON %(table)s" + " (%(columns)s)" + ) % { + "name": index_name, + "table": table, + "columns": ", ".join(columns), + } + c = conn.cursor() + logger.debug("[SQL] %s", sql) c.execute(sql) + if isinstance(self.database_engine, engines.PostgresEngine): + runner = create_index_psql + else: + runner = create_index_sqlite + @defer.inlineCallbacks def updater(progress, batch_size): logger.info("Adding index %s to %s", index_name, table) - if conc: - yield self.runWithConnection(create_index_concurrently) - else: - yield self.runWithConnection(create_index) + yield self.runWithConnection(runner) yield self._end_background_update(update_name) defer.returnValue(1) |