diff --git a/changelog.d/11583.bugfix b/changelog.d/11583.bugfix
new file mode 100644
index 0000000000..d2ed113e21
--- /dev/null
+++ b/changelog.d/11583.bugfix
@@ -0,0 +1 @@
+Fix a performance regression in `/sync` handling, introduced in 1.49.0.
diff --git a/synapse/rest/client/sync.py b/synapse/rest/client/sync.py
index dd90ffa123..8c4b0f6e5d 100644
--- a/synapse/rest/client/sync.py
+++ b/synapse/rest/client/sync.py
@@ -525,7 +525,15 @@ class SyncRestServlet(RestServlet):
time_now=time_now,
# Don't bother to bundle aggregations if the timeline is unlimited,
# as clients will have all the necessary information.
- bundle_aggregations=room.timeline.limited,
+ # bundle_aggregations=room.timeline.limited,
+ #
+ # richvdh 2021-12-15: disable this temporarily as it has too high an
+ # overhead for initialsyncs. We need to figure out a way that the
+ # bundling can be done *before* the events are stored in the
+ # SyncResponseCache so that this part can be synchronous.
+ #
+ # Ensure to re-enable the test at tests/rest/client/test_relations.py::RelationsTestCase.test_bundled_aggregations.
+ bundle_aggregations=False,
token_id=token_id,
event_format=event_formatter,
only_event_fields=only_fields,
diff --git a/tests/rest/client/test_relations.py b/tests/rest/client/test_relations.py
index 55f4f0b1d0..c026d526ef 100644
--- a/tests/rest/client/test_relations.py
+++ b/tests/rest/client/test_relations.py
@@ -577,11 +577,11 @@ class RelationsTestCase(unittest.HomeserverTestCase):
assert_bundle(channel.json_body["event"]["unsigned"].get("m.relations"))
# Request sync.
- channel = self.make_request("GET", "/sync", access_token=self.user_token)
- self.assertEquals(200, channel.code, channel.json_body)
- room_timeline = channel.json_body["rooms"]["join"][self.room]["timeline"]
- self.assertTrue(room_timeline["limited"])
- _find_and_assert_event(room_timeline["events"])
+ # channel = self.make_request("GET", "/sync", access_token=self.user_token)
+ # self.assertEquals(200, channel.code, channel.json_body)
+ # room_timeline = channel.json_body["rooms"]["join"][self.room]["timeline"]
+ # self.assertTrue(room_timeline["limited"])
+ # _find_and_assert_event(room_timeline["events"])
# Note that /relations is tested separately in test_aggregation_get_event_for_thread
# since it needs different data configured.
|
