diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/federation/federation_server.py | 17 | ||||
| -rw-r--r-- | synapse/storage/databases/main/event_federation.py | 104 |
2 files changed, 119 insertions, 2 deletions
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 2892a11d7d..145b9161d9 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -1024,6 +1024,23 @@ class FederationServer(FederationBase): origin, event = next + # Prune the event queue if it's getting large. + # + # We do this *after* handling the first event as the common case is + # that the queue is empty (/has the single event in), and so there's + # no need to do this check. + pruned = await self.store.prune_staged_events_in_room(room_id, room_version) + if pruned: + # If we have pruned the queue check we need to refetch the next + # event to handle. + next = await self.store.get_next_staged_event_for_room( + room_id, room_version + ) + if not next: + break + + origin, event = next + lock = await self.store.try_acquire_lock( _INBOUND_EVENT_HANDLING_LOCK_NAME, room_id ) diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py index 547e43ab98..44018c1c31 100644 --- a/synapse/storage/databases/main/event_federation.py +++ b/synapse/storage/databases/main/event_federation.py @@ -16,11 +16,11 @@ import logging from queue import Empty, PriorityQueue from typing import Collection, Dict, Iterable, List, Optional, Set, Tuple -from prometheus_client import Gauge +from prometheus_client import Counter, Gauge from synapse.api.constants import MAX_DEPTH from synapse.api.errors import StoreError -from synapse.api.room_versions import RoomVersion +from synapse.api.room_versions import EventFormatVersions, RoomVersion from synapse.events import EventBase, make_event_from_dict from synapse.metrics.background_process_metrics import wrap_as_background_process from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause @@ -44,6 +44,12 @@ number_pdus_in_federation_queue = Gauge( "The total number of events in the inbound federation staging", ) +pdus_pruned_from_federation_queue = Counter( + "synapse_federation_server_number_inbound_pdu_pruned", + "The number of events in the inbound federation staging that have been " + "pruned due to the queue getting too long", +) + logger = logging.getLogger(__name__) @@ -1277,6 +1283,100 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas return origin, event + async def prune_staged_events_in_room( + self, + room_id: str, + room_version: RoomVersion, + ) -> bool: + """Checks if there are lots of staged events for the room, and if so + prune them down. + + Returns: + Whether any events were pruned + """ + + # First check the size of the queue. + count = await self.db_pool.simple_select_one_onecol( + table="federation_inbound_events_staging", + keyvalues={"room_id": room_id}, + retcol="COALESCE(COUNT(*), 0)", + desc="prune_staged_events_in_room_count", + ) + + if count < 100: + return False + + # If the queue is too large, then we want clear the entire queue, + # keeping only the forward extremities (i.e. the events not referenced + # by other events in the queue). We do this so that we can always + # backpaginate in all the events we have dropped. + rows = await self.db_pool.simple_select_list( + table="federation_inbound_events_staging", + keyvalues={"room_id": room_id}, + retcols=("event_id", "event_json"), + desc="prune_staged_events_in_room_fetch", + ) + + # Find the set of events referenced by those in the queue, as well as + # collecting all the event IDs in the queue. + referenced_events: Set[str] = set() + seen_events: Set[str] = set() + for row in rows: + event_id = row["event_id"] + seen_events.add(event_id) + event_d = db_to_json(row["event_json"]) + + # We don't bother parsing the dicts into full blown event objects, + # as that is needlessly expensive. + + # We haven't checked that the `prev_events` have the right format + # yet, so we check as we go. + prev_events = event_d.get("prev_events", []) + if not isinstance(prev_events, list): + logger.info("Invalid prev_events for %s", event_id) + continue + + if room_version.event_format == EventFormatVersions.V1: + for prev_event_tuple in prev_events: + if not isinstance(prev_event_tuple, list) or len(prev_events) != 2: + logger.info("Invalid prev_events for %s", event_id) + break + + prev_event_id = prev_event_tuple[0] + if not isinstance(prev_event_id, str): + logger.info("Invalid prev_events for %s", event_id) + break + + referenced_events.add(prev_event_id) + else: + for prev_event_id in prev_events: + if not isinstance(prev_event_id, str): + logger.info("Invalid prev_events for %s", event_id) + break + + referenced_events.add(prev_event_id) + + to_delete = referenced_events & seen_events + if not to_delete: + return False + + pdus_pruned_from_federation_queue.inc(len(to_delete)) + logger.info( + "Pruning %d events in room %s from federation queue", + len(to_delete), + room_id, + ) + + await self.db_pool.simple_delete_many( + table="federation_inbound_events_staging", + keyvalues={"room_id": room_id}, + iterable=to_delete, + column="event_id", + desc="prune_staged_events_in_room_delete", + ) + + return True + async def get_all_rooms_with_staged_incoming_events(self) -> List[str]: """Get the room IDs of all events currently staged.""" return await self.db_pool.simple_select_onecol( |