That explains it. Your discussion of triggers was unrelated to Galera. Thanks!

I must have been unclear. I tried to make it clear that triggers work just fine (as do events). However, my experience with people using triggers (and especially events) is that most people expect them to do something else than they actually do. This experience is already from classic MySQL replication and I have simply continued to advocate the same advice for Galera users: Don’t use features that you don’t understand. (For the same reasons, I discourage most people from using Pacemaker or SANs too…)

In the case of events this is particularly easy to understand: Most people expect an event to fire only once. In reality it will fire on each node. I have also seen attempts to manage this so that an event would fire only on the master, and then if there is a failover your scripts will enable and disable the event on nodes so that it will again be enabled only on the new master. This imo only makes things worse…

Still, it would be wrong to say that events (or triggers) don’t work with MySQL replication, or with Galera, because they work just fine. The problem is just that most people don’t understand what will actually happen if you use them.