From daf498e099394e206709bbc7a330be4a989e31d5 Mon Sep 17 00:00:00 2001 From: Eric Eastwood Date: Thu, 14 Oct 2021 18:53:45 -0500 Subject: Fix 500 error on `/messages` when we accumulate more than 5 backward extremities (#11027) Found while working on the Gitter backfill script and noticed it only happened after we sent 7 batches, https://gitlab.com/gitterHQ/webapp/-/merge_requests/2229#note_665906390 When there are more than 5 backward extremities for a given depth, backfill will throw an error because we sliced the extremity list to 5 but then try to iterate over the full list. This causes us to look for state that we never fetched and we get a `KeyError`. Before when calling `/messages` when there are more than 5 backward extremities: ``` Traceback (most recent call last): File "/usr/local/lib/python3.8/site-packages/synapse/http/server.py", line 258, in _async_render_wrapper callback_return = await self._async_render(request) File "/usr/local/lib/python3.8/site-packages/synapse/http/server.py", line 446, in _async_render callback_return = await raw_callback_return File "/usr/local/lib/python3.8/site-packages/synapse/rest/client/room.py", line 580, in on_GET msgs = await self.pagination_handler.get_messages( File "/usr/local/lib/python3.8/site-packages/synapse/handlers/pagination.py", line 396, in get_messages await self.hs.get_federation_handler().maybe_backfill( File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 133, in maybe_backfill return await self._maybe_backfill_inner(room_id, current_depth, limit) File "/usr/local/lib/python3.8/site-packages/synapse/handlers/federation.py", line 386, in _maybe_backfill_inner likely_extremeties_domains = get_domains_from_state(states[e_id]) KeyError: '$zpFflMEBtZdgcMQWTakaVItTLMjLFdKcRWUPHbbSZJl' ``` --- changelog.d/11027.bugfix | 1 + 1 file changed, 1 insertion(+) create mode 100644 changelog.d/11027.bugfix (limited to 'changelog.d') diff --git a/changelog.d/11027.bugfix b/changelog.d/11027.bugfix new file mode 100644 index 0000000000..ae6cc44470 --- /dev/null +++ b/changelog.d/11027.bugfix @@ -0,0 +1 @@ +Fix 500 error on `/messages` when the server accumulates more than 5 backwards extremities at a given depth for a room. -- cgit 1.4.1