Commit Graph

1 Commits (ef331c52af7606062d9d7584e6c004cf363d01eb)

Author SHA1 Message Date
Kegsay f8d3a762c4
Add a per-room mutex to federationapi when processing transactions (#1810)
* Add a per-room mutex to federationapi when processing transactions

This has numerous benefits:
 - Prevents us doing lots of state resolutions in busy rooms. Previously, room forks would always result
   in a state resolution being performed immediately, without checking if we were already doing this in
   a different transaction. Now they will queue up, resulting in fewer calls to `/state_ids`, `/g_m_e`, etc.
 - Prevents memory usage from growing too large as a result and potentially OOMing.

And costs:
 - High traffic rooms will be slightly slower due to head-of-line blocking from other servers,
   though this has always been an issue as roomserver has a per-room mutex already.

* Fix unit tests

* Correct mutex lock ordering
2021-03-30 10:01:32 +01:00