Galera arbitrator comes with the galera cluster and it’s a daemon to avoid an split brain situation for a mysql cluster typically configured with two nodes. An split brain in clustering is a situation where one node of a cluster is not
MySQL Multi Master replication with Galera
Galera is a synchronous multi-master cluster for MySQL/InnoDB databases. Some features and benefits of Galera are: Synchronous replication. Multi master topology. Read/Write to any cluster node. Automatic membership control. Data consistency between replica nodes. Read and write nodes scalability. Distributed