Making HAProxy High Available for MySQL Galera Cluster

oli.sennhauser@fromdual.com (Oli Sennhauser) — Sun, 14 Dec 2014 18:37:50 +0000

After properly installing and testing a Galera Cluster we see that the set-up is not finished yet. It needs something in front of the Galera Cluster that balances the load over all nodes.
So we install a load balancer in front of the Galera Cluster. Typically nowadays HAProxy is chosen for this purpose. But then we find, that the whole Galera Cluster is still not high available in case the load balancer fails or dies. So we need a second load balancer for high availability.
But how should we properly failover when the HAProxy load balancer dies? For this purpose we put a Virtual IP (VIP) in front of the HAProxy load balancer pair. The Virtual IP is controlled and failovered with Keepalived.

Virtual Ip on FromDual GmbH

Making HAProxy High Available for MySQL Galera Cluster