summary refs log tree commit diff
path: root/changelog.d
diff options
context:
space:
mode:
authorEric Eastwood <erice@element.io>2021-10-14 18:53:45 -0500
committerGitHub <noreply@github.com>2021-10-14 18:53:45 -0500
commitdaf498e099394e206709bbc7a330be4a989e31d5 (patch)
tree4745df6d8fa6d78006d0db278576c41d8e42a2e8 /changelog.d
parentEnsure each charset is attempted only once during media preview. (#11089) (diff)
downloadsynapse-daf498e099394e206709bbc7a330be4a989e31d5.tar.xz
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'
```
Diffstat (limited to 'changelog.d')
-rw-r--r--changelog.d/11027.bugfix1
1 files changed, 1 insertions, 0 deletions
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.