New Galera cluster running in production
Two important databases are using the new (mariadb) galera cluster now: https://connect.opensuse.org and https://progress.opensuse.org are now completely migrated.
As we reported in one of our last news, we setup a new galera cluster for all our applications that make use of MySQL. This cluster should allow us to do maintenance on one of the cluster nodes at any time - and also should scale the workload between the nodes, via the HaProxy in front.
One problem, that affected us for example in case of progress.opensuse.org, are the MyISAM tables: Galera is not really ready (yet?) to sync the content of such tables (even if you can enable the "experimental" feature, if you don't care much about your data). As result, we do not only need to have a look and migrate each an every single MyISAM table - but more worse, we also need to have a look at the used code of the application to identify problematic SQL statements (like DELAYED inserts for example) - and patch it where needed.
But the good news for the two databases mentioned: so far everything seems (still) to work. Other applications will follow one by one (as some like connect need adaptions).