Galera Cluster is a contemporary multi-master database cluster that is designed keeping in mind the contemporary replication, MySQL (or MariaDB), and InnoDB. It is used to direct read and write databases to any node. An individual node can be lost if the operation is uninterrupted and when the complex failover procedures are not being used.
How Does MariaDB Galera Cluster Work?
Galera Cluster is only available on Linux and supports the InnoDB storage engine. It consists of the database server that uses the Galera Replication Plugins to direct replication efficiently. MariaDB replication plugin API is extended to deliver all the information and secure necessary for true multi-master, synchronous replication. This extended API is known as Write-Set Replication API (or wsrep).
This API enables MariaDB Galera Cluster to deliver certification-based replication. It consists of database rows to replicate and the information related to the entire locks held by the database during the transaction. Then, in the applier queue, each node certifies the replicated write-set against another write-set. This write-set is applied to the conflicting locks that are not required. Now, the transaction is considered committed. Later, each of these nodes continues to apply it to the tablespace.