diff options
| -rw-r--r-- | changelog.d/16640.misc | 1 | ||||
| -rw-r--r-- | synapse/replication/tcp/handler.py | 34 | ||||
| -rw-r--r-- | synapse/replication/tcp/streams/_base.py | 18 |
3 files changed, 53 insertions, 0 deletions
diff --git a/changelog.d/16640.misc b/changelog.d/16640.misc new file mode 100644 index 0000000000..3b1cc2185d --- /dev/null +++ b/changelog.d/16640.misc @@ -0,0 +1 @@ +More efficiently handle no-op `POSITION` over replication. diff --git a/synapse/replication/tcp/handler.py b/synapse/replication/tcp/handler.py index afd03137f0..1748182663 100644 --- a/synapse/replication/tcp/handler.py +++ b/synapse/replication/tcp/handler.py @@ -588,6 +588,21 @@ class ReplicationCommandHandler: logger.debug("Handling '%s %s'", cmd.NAME, cmd.to_line()) + # Check if we can early discard this position. We can only do so for + # connected streams. + stream = self._streams[cmd.stream_name] + if stream.can_discard_position( + cmd.instance_name, cmd.prev_token, cmd.new_token + ) and self.is_stream_connected(conn, cmd.stream_name): + logger.debug( + "Discarding redundant POSITION %s/%s %s %s", + cmd.instance_name, + cmd.stream_name, + cmd.prev_token, + cmd.new_token, + ) + return + self._add_command_to_stream_queue(conn, cmd) async def _process_position( @@ -599,6 +614,18 @@ class ReplicationCommandHandler: """ stream = self._streams[stream_name] + if stream.can_discard_position( + cmd.instance_name, cmd.prev_token, cmd.new_token + ) and self.is_stream_connected(conn, cmd.stream_name): + logger.debug( + "Discarding redundant POSITION %s/%s %s %s", + cmd.instance_name, + cmd.stream_name, + cmd.prev_token, + cmd.new_token, + ) + return + # We're about to go and catch up with the stream, so remove from set # of connected streams. for streams in self._streams_by_connection.values(): @@ -657,6 +684,13 @@ class ReplicationCommandHandler: self._streams_by_connection.setdefault(conn, set()).add(stream_name) + def is_stream_connected( + self, conn: IReplicationConnection, stream_name: str + ) -> bool: + """Return if stream has been successfully connected and is ready to + receive updates""" + return stream_name in self._streams_by_connection.get(conn, ()) + def on_REMOTE_SERVER_UP( self, conn: IReplicationConnection, cmd: RemoteServerUpCommand ) -> None: diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py index 58a44029aa..cc34dfb322 100644 --- a/synapse/replication/tcp/streams/_base.py +++ b/synapse/replication/tcp/streams/_base.py @@ -144,6 +144,16 @@ class Stream: """ raise NotImplementedError() + def can_discard_position( + self, instance_name: str, prev_token: int, new_token: int + ) -> bool: + """Whether or not a position command for this stream can be discarded. + + Useful for streams that can never go backwards and where we already know + the stream ID for the instance has advanced. + """ + return False + def discard_updates_and_advance(self) -> None: """Called when the stream should advance but the updates would be discarded, e.g. when there are no currently connected workers. @@ -221,6 +231,14 @@ class _StreamFromIdGen(Stream): def minimal_local_current_token(self) -> Token: return self._stream_id_gen.get_minimal_local_current_token() + def can_discard_position( + self, instance_name: str, prev_token: int, new_token: int + ) -> bool: + # These streams can't go backwards, so we know we can ignore any + # positions where the tokens are from before the current token. + + return new_token <= self.current_token(instance_name) + def current_token_without_instance( current_token: Callable[[], int] |