The deployment of 1.31.0-wmf.22 revealed a critical bug[1] immediately
after I pushed the new branch to group1 wikis. Group1 was rolled back to
wmf.21 pending the resolution of T187942. Refer to Phabricator for details
and discussion. I will attempt to resume the train later today, assuming
blockers[2] have been resolved.
1. Replication lag detection broken in wmf.22
https://phabricator.wikimedia.org/T187942
2. 1.31.0-wmf.22 deployment blockers
https://phabricator.wikimedia.org/T183961