With our 3 controller servers running on a bare bones Ubuntu install, it's time to start getting the services required for OpenStack up and running. Before any of the actual cloud services can be installed, we need a shared database and message queue. Because our design goal here is both redundancy and load balancing, we can't just install a basic MySQL package. A little researched showed that there are 3 options for a MySQL compatible multi-master cluster: MySQL w/ a wsrep patch, MariaDB, or Percona XtraDB Cluster. In all cases Galera is used as the actual clustering mechanism. For ease of installation (and because it has solid Ubuntu package support), we decided to use MariaDB + Galera for the clustered database.
