I'm still trying to find time for a writeup of how we use MySQL Galera, but I'll take this chance to note again that any big MySQL houses out there should really take a look at it and see if it will work within your environment. Basically it's a true multi-master MySQL environment with shared-nothing (kind of like MySQL cluster). We've run into our share of bugs, be we're perhaps more of an edge case. We create a TON of temporary tables and were encountering a bug which was eating up memory slowly. That has been fixed for a couple releases now and everything has been groovy.

Basically though, the cluster takes care of ejecting bad slaves so you'll never need to worry about the replication status, etc.

Oh, and feel free to contact me through profile if you have any questions about it. We have a good long use of it now and pretty much know about most/all of the things to watch out for.