Galera is a multimaster cluster for MariaDB, which is based on synchronous replication between all cluster nodes. Effectively, Galera treats a cluster of MariaDB nodes as one single master node that reads and writes to all nodes. Galera replication happens at transaction commit time, by broadcasting the transaction write set to the cluster for application. Client connects directly to the DBMS and experiences close to the native DBMS behavior. write set replication (wsrep) API defines the interface between Galera replication and the DBMS:
In this section, we will install Galera cluster packages for MariaDB on our three controller nodes, then we will configure Pacemaker to monitor all Galera services.
Pacemaker can be stopped on all cluster nodes, as shown, if it is running from the previous steps:
# pcs cluster stop --all