Galera Cluster (Experimental)
Info:
This template creates a MariaDB Galera cluster on top of Rancher. Using the Galera plugin, the MariaDB cluster runs in a multi-master replicated mode.
When deployed from the catalog, a three node cluster is created with a database, root password, database user and password. The cluster is set up for replication between all of the nodes. The cluster sits behind a light weight proxy layer that forwards all reads/writes to a single server in order for transaction locks. The proxy layer is fronted by a Rancher load balancer.
Clients should access the cluster through the load balancer so they do not need to be updated in the event of a failure.
When the cluster is completely stopped and started, user intervention is required to bring it back online. Instructions can be found in the Galera documentation.
The replication mechanism used in the cluster is based on the MySQL dump method. This has the side effect of taking a long time to bring in a new node when there are large data sets.
Usage:
Once deployed, use a mysql client to connect:
mysql -u<db_user> -p -h<galera-lb>