diff --git a/synapse/config/server.py b/synapse/config/server.py
index c6d58effd4..6d88231843 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -505,6 +505,9 @@ class ServerConfig(Config):
"cleanup_extremities_with_dummy_events", True
)
+ # The number of forward extremities in a room needed to send a dummy event.
+ self.dummy_events_threshold = config.get("dummy_events_threshold", 10)
+
self.enable_ephemeral_messages = config.get("enable_ephemeral_messages", False)
# Inhibits the /requestToken endpoints from returning an error that might leak
@@ -823,6 +826,18 @@ class ServerConfig(Config):
# bind_addresses: ['::1', '127.0.0.1']
# type: manhole
+ # Forward extremities can build up in a room due to networking delays between
+ # homeservers. Once this happens in a large room, calculation of the state of
+ # that room can become quite expensive. To mitigate this, once the number of
+ # forward extremities reaches a given threshold, Synapse will send an
+ # org.matrix.dummy_event event, which will reduce the forward extremities
+ # in the room.
+ #
+ # This setting defines the threshold (i.e. number of forward extremities in the
+ # room) at which dummy events are sent. The default value is 10.
+ #
+ #dummy_events_threshold: 5
+
## Homeserver blocking ##
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index a324f09340..a622a600b4 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -419,6 +419,8 @@ class EventCreationHandler(object):
self._ephemeral_events_enabled = hs.config.enable_ephemeral_messages
+ self._dummy_events_threshold = hs.config.dummy_events_threshold
+
@defer.inlineCallbacks
def create_event(
self,
@@ -1085,7 +1087,7 @@ class EventCreationHandler(object):
"""
self._expire_rooms_to_exclude_from_dummy_event_insertion()
room_ids = await self.store.get_rooms_with_many_extremities(
- min_count=10,
+ min_count=self._dummy_events_threshold,
limit=5,
room_id_filter=self._rooms_to_exclude_from_dummy_event_insertion.keys(),
)
|
