diff options
Diffstat (limited to 'synapse/storage/util')
| -rw-r--r-- | synapse/storage/util/id_generators.py | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py index 51f680d05d..d7e40aaa8b 100644 --- a/synapse/storage/util/id_generators.py +++ b/synapse/storage/util/id_generators.py @@ -24,6 +24,7 @@ from typing_extensions import Deque from synapse.metrics.background_process_metrics import run_as_background_process from synapse.storage.database import DatabasePool, LoggingTransaction +from synapse.storage.types import Cursor from synapse.storage.util.sequence import PostgresSequenceGenerator logger = logging.getLogger(__name__) @@ -548,7 +549,7 @@ class MultiWriterIdGenerator: # do. break - def _update_stream_positions_table_txn(self, txn): + def _update_stream_positions_table_txn(self, txn: Cursor): """Update the `stream_positions` table with newly persisted position. """ @@ -598,10 +599,13 @@ class _MultiWriterCtxManager: stream_ids = attr.ib(type=List[int], factory=list) async def __aenter__(self) -> Union[int, List[int]]: + # It's safe to run this in autocommit mode as fetching values from a + # sequence ignores transaction semantics anyway. self.stream_ids = await self.id_gen._db.runInteraction( "_load_next_mult_id", self.id_gen._load_next_mult_id_txn, self.multiple_ids or 1, + db_autocommit=True, ) # Assert the fetched ID is actually greater than any ID we've already @@ -632,10 +636,16 @@ class _MultiWriterCtxManager: # # We only do this on the success path so that the persisted current # position points to a persisted row with the correct instance name. + # + # We do this in autocommit mode as a) the upsert works correctly outside + # transactions and b) reduces the amount of time the rows are locked + # for. If we don't do this then we'll often hit serialization errors due + # to the fact we default to REPEATABLE READ isolation levels. if self.id_gen._writers: await self.id_gen._db.runInteraction( "MultiWriterIdGenerator._update_table", self.id_gen._update_stream_positions_table_txn, + db_autocommit=True, ) return False |