From a6ea1a957e8e38ca3f98d4da32ee49a40fcb4807 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 28 Oct 2020 12:11:45 +0000 Subject: [PATCH] Don't pull event from DB when handling replication traffic. (#8669) I was trying to make it so that we didn't have to start a background task when handling RDATA, but that is a bigger job (due to all the code in `generic_worker`). However I still think not pulling the event from the DB may help reduce some DB usage due to replication, even if most workers will simply go and pull that event from the DB later anyway. Co-authored-by: Patrick Cloke --- changelog.d/8669.misc | 1 + synapse/notifier.py | 68 +++++++++++++++---- synapse/replication/tcp/client.py | 20 +++--- synapse/replication/tcp/streams/events.py | 21 +++--- .../storage/databases/main/events_worker.py | 8 ++- 5 files changed, 87 insertions(+), 31 deletions(-) create mode 100644 changelog.d/8669.misc diff --git a/changelog.d/8669.misc b/changelog.d/8669.misc new file mode 100644 index 000000000..5228105cd --- /dev/null +++ b/changelog.d/8669.misc @@ -0,0 +1 @@ +Don't pull event from DB when handling replication traffic. diff --git a/synapse/notifier.py b/synapse/notifier.py index eb56b26f2..a17352ef4 100644 --- a/synapse/notifier.py +++ b/synapse/notifier.py @@ -28,6 +28,7 @@ from typing import ( Union, ) +import attr from prometheus_client import Counter from twisted.internet import defer @@ -173,6 +174,17 @@ class EventStreamResult(namedtuple("EventStreamResult", ("events", "tokens"))): return bool(self.events) +@attr.s(slots=True, frozen=True) +class _PendingRoomEventEntry: + event_pos = attr.ib(type=PersistedEventPosition) + extra_users = attr.ib(type=Collection[UserID]) + + room_id = attr.ib(type=str) + type = attr.ib(type=str) + state_key = attr.ib(type=Optional[str]) + membership = attr.ib(type=Optional[str]) + + class Notifier: """ This class is responsible for notifying any listeners when there are new events available for it. @@ -190,9 +202,7 @@ class Notifier: self.storage = hs.get_storage() self.event_sources = hs.get_event_sources() self.store = hs.get_datastore() - self.pending_new_room_events = ( - [] - ) # type: List[Tuple[PersistedEventPosition, EventBase, Collection[UserID]]] + self.pending_new_room_events = [] # type: List[_PendingRoomEventEntry] # Called when there are new things to stream over replication self.replication_callbacks = [] # type: List[Callable[[], None]] @@ -255,7 +265,29 @@ class Notifier: max_room_stream_token: RoomStreamToken, extra_users: Collection[UserID] = [], ): - """ Used by handlers to inform the notifier something has happened + """Unwraps event and calls `on_new_room_event_args`. + """ + self.on_new_room_event_args( + event_pos=event_pos, + room_id=event.room_id, + event_type=event.type, + state_key=event.get("state_key"), + membership=event.content.get("membership"), + max_room_stream_token=max_room_stream_token, + extra_users=extra_users, + ) + + def on_new_room_event_args( + self, + room_id: str, + event_type: str, + state_key: Optional[str], + membership: Optional[str], + event_pos: PersistedEventPosition, + max_room_stream_token: RoomStreamToken, + extra_users: Collection[UserID] = [], + ): + """Used by handlers to inform the notifier something has happened in the room, room event wise. This triggers the notifier to wake up any listeners that are @@ -266,7 +298,16 @@ class Notifier: until all previous events have been persisted before notifying the client streams. """ - self.pending_new_room_events.append((event_pos, event, extra_users)) + self.pending_new_room_events.append( + _PendingRoomEventEntry( + event_pos=event_pos, + extra_users=extra_users, + room_id=room_id, + type=event_type, + state_key=state_key, + membership=membership, + ) + ) self._notify_pending_new_room_events(max_room_stream_token) self.notify_replication() @@ -284,18 +325,19 @@ class Notifier: users = set() # type: Set[UserID] rooms = set() # type: Set[str] - for event_pos, event, extra_users in pending: - if event_pos.persisted_after(max_room_stream_token): - self.pending_new_room_events.append((event_pos, event, extra_users)) + for entry in pending: + if entry.event_pos.persisted_after(max_room_stream_token): + self.pending_new_room_events.append(entry) else: if ( - event.type == EventTypes.Member - and event.membership == Membership.JOIN + entry.type == EventTypes.Member + and entry.membership == Membership.JOIN + and entry.state_key ): - self._user_joined_room(event.state_key, event.room_id) + self._user_joined_room(entry.state_key, entry.room_id) - users.update(extra_users) - rooms.add(event.room_id) + users.update(entry.extra_users) + rooms.add(entry.room_id) if users or rooms: self.on_new_event( diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py index e27ee216f..2618eb1e5 100644 --- a/synapse/replication/tcp/client.py +++ b/synapse/replication/tcp/client.py @@ -141,21 +141,25 @@ class ReplicationDataHandler: if row.type != EventsStreamEventRow.TypeId: continue assert isinstance(row, EventsStreamRow) + assert isinstance(row.data, EventsStreamEventRow) - event = await self.store.get_event( - row.data.event_id, allow_rejected=True - ) - if event.rejected_reason: + if row.data.rejected: continue extra_users = () # type: Tuple[UserID, ...] - if event.type == EventTypes.Member: - extra_users = (UserID.from_string(event.state_key),) + if row.data.type == EventTypes.Member and row.data.state_key: + extra_users = (UserID.from_string(row.data.state_key),) max_token = self.store.get_room_max_token() event_pos = PersistedEventPosition(instance_name, token) - self.notifier.on_new_room_event( - event, event_pos, max_token, extra_users + self.notifier.on_new_room_event_args( + event_pos=event_pos, + max_room_stream_token=max_token, + extra_users=extra_users, + room_id=row.data.room_id, + event_type=row.data.type, + state_key=row.data.state_key, + membership=row.data.membership, ) # Notify any waiting deferreds. The list is ordered by position so we diff --git a/synapse/replication/tcp/streams/events.py b/synapse/replication/tcp/streams/events.py index 82e9e0d64..86a62b71e 100644 --- a/synapse/replication/tcp/streams/events.py +++ b/synapse/replication/tcp/streams/events.py @@ -15,12 +15,15 @@ # limitations under the License. import heapq from collections.abc import Iterable -from typing import List, Tuple, Type +from typing import TYPE_CHECKING, List, Optional, Tuple, Type import attr from ._base import Stream, StreamUpdateResult, Token +if TYPE_CHECKING: + from synapse.server import HomeServer + """Handling of the 'events' replication stream This stream contains rows of various types. Each row therefore contains a 'type' @@ -81,12 +84,14 @@ class BaseEventsStreamRow: class EventsStreamEventRow(BaseEventsStreamRow): TypeId = "ev" - event_id = attr.ib() # str - room_id = attr.ib() # str - type = attr.ib() # str - state_key = attr.ib() # str, optional - redacts = attr.ib() # str, optional - relates_to = attr.ib() # str, optional + event_id = attr.ib(type=str) + room_id = attr.ib(type=str) + type = attr.ib(type=str) + state_key = attr.ib(type=Optional[str]) + redacts = attr.ib(type=Optional[str]) + relates_to = attr.ib(type=Optional[str]) + membership = attr.ib(type=Optional[str]) + rejected = attr.ib(type=bool) @attr.s(slots=True, frozen=True) @@ -113,7 +118,7 @@ class EventsStream(Stream): NAME = "events" - def __init__(self, hs): + def __init__(self, hs: "HomeServer"): self._store = hs.get_datastore() super().__init__( hs.get_instance_name(), diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py index cd1f31aa6..5ae263827 100644 --- a/synapse/storage/databases/main/events_worker.py +++ b/synapse/storage/databases/main/events_worker.py @@ -1117,11 +1117,13 @@ class EventsWorkerStore(SQLBaseStore): def get_all_new_forward_event_rows(txn): sql = ( "SELECT e.stream_ordering, e.event_id, e.room_id, e.type," - " state_key, redacts, relates_to_id" + " state_key, redacts, relates_to_id, membership, rejections.reason IS NOT NULL" " FROM events AS e" " LEFT JOIN redactions USING (event_id)" " LEFT JOIN state_events USING (event_id)" " LEFT JOIN event_relations USING (event_id)" + " LEFT JOIN room_memberships USING (event_id)" + " LEFT JOIN rejections USING (event_id)" " WHERE ? < stream_ordering AND stream_ordering <= ?" " AND instance_name = ?" " ORDER BY stream_ordering ASC" @@ -1152,12 +1154,14 @@ class EventsWorkerStore(SQLBaseStore): def get_ex_outlier_stream_rows_txn(txn): sql = ( "SELECT event_stream_ordering, e.event_id, e.room_id, e.type," - " state_key, redacts, relates_to_id" + " state_key, redacts, relates_to_id, membership, rejections.reason IS NOT NULL" " FROM events AS e" " INNER JOIN ex_outlier_stream AS out USING (event_id)" " LEFT JOIN redactions USING (event_id)" " LEFT JOIN state_events USING (event_id)" " LEFT JOIN event_relations USING (event_id)" + " LEFT JOIN room_memberships USING (event_id)" + " LEFT JOIN rejections USING (event_id)" " WHERE ? < event_stream_ordering" " AND event_stream_ordering <= ?" " AND out.instance_name = ?"