Fix federation stall on concurrent access errors

changelog.d/9639.bugfix

@@ -0,0 +1 @@
+Fix bug where federation sending can stall due to `concurrent access` database exceptions when it falls behind.

synapse/storage/databases/main/transactions.py

@@ -22,7 +22,6 @@
 from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.storage._base import SQLBaseStore, db_to_json
 from synapse.storage.database import DatabasePool, LoggingTransaction
-from synapse.storage.engines import PostgresEngine, Sqlite3Engine
 from synapse.types import JsonDict
 from synapse.util.caches.expiringcache import ExpiringCache
 
@@ -312,49 +311,23 @@ async def store_destination_rooms_entries(
  stream_ordering: the stream_ordering of the event
  """
 
- return await self.db_pool.runInteraction(
- "store_destination_rooms_entries",
- self._store_destination_rooms_entries_txn,
- destinations,
- room_id,
- stream_ordering,
+ await self.db_pool.simple_upsert_many(
+ table="destinations",
+ key_names=("destination",),
+ key_values=[(d,) for d in destinations],
+ value_names=[],
+ value_values=[],
+ desc="store_destination_rooms_entries_dests",
  )
 
- def _store_destination_rooms_entries_txn(
- self,
- txn: LoggingTransaction,
- destinations: Iterable[str],
- room_id: str,
- stream_ordering: int,
- ) -> None:
-
- # ensure we have a `destinations` row for this destination, as there is
- # a foreign key constraint.
- if isinstance(self.database_engine, PostgresEngine):
- q = """
- INSERT INTO destinations (destination)
- VALUES (?)
- ON CONFLICT DO NOTHING;
- """
- elif isinstance(self.database_engine, Sqlite3Engine):
- q = """
- INSERT OR IGNORE INTO destinations (destination)
- VALUES (?);
- """
- else:
- raise RuntimeError("Unknown database engine")
-
- txn.execute_batch(q, ((destination,) for destination in destinations))
-
  rows = [(destination, room_id) for destination in destinations]
-
- self.db_pool.simple_upsert_many_txn(
- txn,
+ await self.db_pool.simple_upsert_many(
  table="destination_rooms",
  key_names=("destination", "room_id"),
  key_values=rows,
  value_names=["stream_ordering"],
  value_values=[(stream_ordering,)] * len(rows),
+ desc="store_destination_rooms_entries_rooms",
  )
 
  async def get_destination_last_successful_stream_ordering(