In order to continue with T239791: DB: perform rolling restart of mariadb daemons to pick up CA changes we'd need to restart MySQL on m3 host (db1128).
As we have to restart MySQL, we will also upgrade it to the newer version.
We'd like if you can help us and set phabricator on read-only before we do the restart, as we normally do when there's a maintenance involving this master.
This restart shouldn't take more than a few seconds, the proxy will failover reads to the other replica, so reads shouldn't be affected that much, writes will obviously blocked for a few seconds.
We should probably email wikitech-l@ once we've picked up a date/time.
I was thinking about Wednesday 12th February at 06:00 AM UTC? Would that work for you @mmodell? I can do it earlier if needed, like 05:00 AM UTC if that works best for you.