Configuring HA Proxy for the MariaDB Galera cluster
With our MariaDB Galera cluster configured, each node can take traffic, and the writes are seamlessly replicated to other nodes in the cluster. We could use any of the MariaDB node addresses and place them in our configuration files, but if that node failed, we would not have a database to attach to and our OpenStack environment would fail. A possible solution to this is to front the MariaDB cluster using Load Balancing. Given that any of the nodes can take reads and writes, with data consistency, Load Balancing is a great solution. Generally, physical Load Balancers, such as those from F5 or Brocade, are recommended. In the absence of physical Load Balancers, High Availability (HA) Proxy can be used.
Getting ready
Install two servers, both running Ubuntu 14.04, which are configured on the same management network as our OpenStack environment and the MariaDB Galera cluster. In the following steps, the two nodes will be on the IP addresses...