diff options
| -rw-r--r-- | changelog.d/14905.feature | 1 | ||||
| -rw-r--r-- | docs/upgrade.md | 13 | ||||
| -rw-r--r-- | synapse/config/experimental.py | 2 | ||||
| -rw-r--r-- | synapse/storage/databases/main/stream.py | 40 |
4 files changed, 49 insertions, 7 deletions
diff --git a/changelog.d/14905.feature b/changelog.d/14905.feature new file mode 100644 index 0000000000..f13a4af981 --- /dev/null +++ b/changelog.d/14905.feature @@ -0,0 +1 @@ +Faster joins: request partial joins by default. Admins can opt-out of this for the time being---see the upgrade notes. diff --git a/docs/upgrade.md b/docs/upgrade.md index 0d486a3c82..6316db563b 100644 --- a/docs/upgrade.md +++ b/docs/upgrade.md @@ -90,6 +90,19 @@ process, for example: # Upgrading to v1.76.0 +## Faster joins are enabled by default + +When joining a room for the first time, Synapse 1.76.0rc1 will request a partial join from the other server by default. Previously, server admins had to opt-in to this using an experimental config flag. + +Server admins can opt out of this feature for the time being by setting + +```yaml +experimental: + faster_joins: false +``` + +in their server config. + ## Changes to the account data replication streams Synapse has changed the format of the account data and devices replication diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py index 89586db763..2590c88cde 100644 --- a/synapse/config/experimental.py +++ b/synapse/config/experimental.py @@ -84,7 +84,7 @@ class ExperimentalConfig(Config): # experimental support for faster joins over federation # (MSC2775, MSC3706, MSC3895) # requires a target server that can provide a partial join response (MSC3706) - self.faster_joins_enabled: bool = experimental.get("faster_joins", False) + self.faster_joins_enabled: bool = experimental.get("faster_joins", True) # MSC3720 (Account status endpoint) self.msc3720_enabled: bool = experimental.get("msc3720_enabled", False) diff --git a/synapse/storage/databases/main/stream.py b/synapse/storage/databases/main/stream.py index 63d8350530..d28fc65df9 100644 --- a/synapse/storage/databases/main/stream.py +++ b/synapse/storage/databases/main/stream.py @@ -67,7 +67,7 @@ from synapse.storage.database import ( make_in_list_sql_clause, ) from synapse.storage.databases.main.events_worker import EventsWorkerStore -from synapse.storage.engines import BaseDatabaseEngine, PostgresEngine +from synapse.storage.engines import BaseDatabaseEngine, PostgresEngine, Sqlite3Engine from synapse.storage.util.id_generators import MultiWriterIdGenerator from synapse.types import PersistedEventPosition, RoomStreamToken from synapse.util.caches.descriptors import cached @@ -944,12 +944,40 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore): room_id stream_key """ - sql = ( - "SELECT coalesce(MIN(topological_ordering), 0) FROM events" - " WHERE room_id = ? AND stream_ordering >= ?" - ) + if isinstance(self.database_engine, PostgresEngine): + min_function = "LEAST" + elif isinstance(self.database_engine, Sqlite3Engine): + min_function = "MIN" + else: + raise RuntimeError(f"Unknown database engine {self.database_engine}") + + # This query used to be + # SELECT COALESCE(MIN(topological_ordering), 0) FROM events + # WHERE room_id = ? and events.stream_ordering >= {stream_key} + # which returns 0 if the stream_key is newer than any event in + # the room. That's not wrong, but it seems to interact oddly with backfill, + # requiring a second call to /messages to actually backfill from a remote + # homeserver. + # + # Instead, rollback the stream ordering to that after the most recent event in + # this room. + sql = f""" + WITH fallback(max_stream_ordering) AS ( + SELECT MAX(stream_ordering) + FROM events + WHERE room_id = ? + ) + SELECT COALESCE(MIN(topological_ordering), 0) FROM events + WHERE + room_id = ? + AND events.stream_ordering >= {min_function}( + ?, + (SELECT max_stream_ordering FROM fallback) + ) + """ + row = await self.db_pool.execute( - "get_current_topological_token", None, sql, room_id, stream_key + "get_current_topological_token", None, sql, room_id, room_id, stream_key ) return row[0][0] if row else 0 |