I upgraded one of the nodes of a four node MMR delta syncrepl openldap
system today to 2.4.44 + the backported ITS 8432 patch (the other three
nodes were still running 2.4.41, which all four had been running for
quite some time with no issues) and within a few hours they started blowing
up with the infinite replication issue referred to in ITS 8432, all the
accesslogs were filled with the same modification repeated over and
over. I ended up having to slapcat the db, restore the upgraded node to
2.4.41, and then reload the db on all of them to recover.
From what I understand the bug was supposed to have existed in versions
before 2.4.44, but I had never seen it in 2.4.41, and backing out
to that version seems to have restored stability. I remember seeing
another ITS regarding an issue even with the 8432 patch applied if
you're using the memberOf overlay (although that number escapes me at
the moment), but I thought that only applied if you were updating group
memberships and the change that blew up my system was a password change.
Is it possible updating one node to the fixed version somehow triggered
the bug in one of the other nodes? Do I need to upgrade all the nodes at
the same time? Or are there possibly still edge cases where 2.4.44 with
the patch are still broken? I did a test run of the upgrade in my dev
environment, including the staged rollout with temporarily mixed
versions, but it doesn't really have the same load and variety of access
patterns that production sees.