Dropping a node from MariaDB Galera Cluster

MariaDB Galera Cluster exists so that we can eliminate single points of failure in our infrastructure. Once set up, a single node can be taken out of the cluster for maintenance without impacting the rest of the cluster or causing downtime for our applications.

Getting ready

Create MariaDB Galera Cluster as described in the Installing MariaDB Galera Cluster recipe earlier in this chapter. In this recipe, we'll be shutting down db03.

How to do it...

1. On db03, run the following command to check whether the node is up to date:

   mysql -e "SHOW STATUS LIKE 'wsrep_local_state_comment'"
   

2. If the value is synced, then the node is up to date and we can safely shut down the node with the following command:

   sudo service mysql stop
   

3. On the other cluster nodes, run the following command to check whether the node has been destroyed:

   mysql -e "SHOW STATUS LIKE 'wsrep_%'"
   

4. We'll know the node is destroyed if the number of nodes in wsrep_cluster_size is 2 and the IP address...