Percona -> MariaDB has been super smooth. With Percona over the years I've had a few updates that didn't apply and I had to go in and fix things like repo locations or keys as things evolved, but mostly it was just a workhorse. I guess one issue we had was it would never autostart on a reboot (despite "systemctl enable"), but I was never able to track it down in a reproducible way.

With MariaDB I'm using the digitalocean repos and I guess we'll see how stable those are.

Galera has been great, have used it for 5+ years and only a couple hiccups. This is a rather small database, but nearly mission critical. A couple times the cluster failed to start and I had to figure out the most recent node and manually bootstrap from it. I built some small shell tools to tell me if the cluster was happy, and bootstrap, because I had to do it so in frequently I could never remember the queries and files involved, and didn't want to have to read through my docs when the cluster was down.

Our use case is a small e-mail relay, so the win with galera is each e-mail server also runs a database node, and since they are master/master we can take one node down at a time for maintenance without having to do any failovers or the like.

thanks! good to know