From d9b8d274949df7356e880a67d3aac1b25613ab1f Mon Sep 17 00:00:00 2001 From: Brendan Abolivier Date: Thu, 7 May 2020 11:35:23 +0200 Subject: [PATCH] Add a configuration setting for the dummy event threshold (#7422) Add dummy_events_threshold which allows configuring the number of forward extremities a room needs for Synapse to send forward extremities in it. --- changelog.d/7422.feature | 1 + docs/sample_config.yaml | 12 ++++++++++++ synapse/config/server.py | 15 +++++++++++++++ synapse/handlers/message.py | 4 +++- 4 files changed, 31 insertions(+), 1 deletion(-) create mode 100644 changelog.d/7422.feature diff --git a/changelog.d/7422.feature b/changelog.d/7422.feature new file mode 100644 index 0000000000..d6d5bb2169 --- /dev/null +++ b/changelog.d/7422.feature @@ -0,0 +1 @@ +Add a configuration setting to tweak the threshold for dummy events. diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index fc970986c6..98ead7dc0e 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -253,6 +253,18 @@ listeners: # 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/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(), )