* Increase DB/CPU perf of `_is_server_still_joined` check.
For rooms with large amount of state a single user leaving could cause
us to go and load a lot of membership events and then pull out
membership state in a large number of batches.
* Newsfile
* Update synapse/storage/persist_events.py
Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Fix adding if too soon
* Update docstring
* Review comments
* Woops typo
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
