get a new release!
This will be my first time upgrading. If I have PrivacyIDEA running in a clustered environment, with two PI servers, each running a master-master MySQL cluster, do I need to do anything special on the second server? I know I still need to run the upgrade to update the installed files, but I want to make sure running it on the second server won’t cause problems when it sees the updates done to the DB are already there.
A maintenance release - i.e. a version change in the last number 2.23.1 -> 2.23.4 does not introduce new features or any DB change. So this is basically a change of code.
Anyways, in a HA setup you could stop the second service. Upgrade the first service, run DB schema upgrade (not necessary when upgrading from A.B.x -> A.B.z), upgrade the second server and start the second webserver again. The schema upgrade would be progagated via SQL redundancy.
So,yes, basically upgrade the code on both machines.
In case you are worried about upgrades, reliability, responsibility or response times, you know there are also professional SLAs offered by NetKnights.