In an earlier article we have gone through the process of Certification Based Replication in Galera Cluster for MySQL and MariaDB. To recall the overview, Galera Cluster is a multi-master cluster setup that uses the Galera Replication Plugin for synchronous and certification based database replication. This article examines the concept of Isolation Levels in Galera Cluster, that is an inherent feature of the MySQL InnoDB database engine.
In the earlier articles, we have covered the basics of Galera Cluster for MySQL and MariaDB and another article about MariaDB Galera Cluster in particular. To recall the overview of Galera Cluster – It is a synchronous multi-master cluster that uses the InnoDB storage engine (XtraDB also for MariaDB). It is actually the Galera replication plugin that extends the wsrep API of the underlying DBMS, MySQL or MariaDB. Galera Cluster uses Certification based synchronous replication in the multi master server setup. In this article we will look into the technical aspects of Galera Cluster Certification based replication functionality.
Galera Cluster for MySQL is a MySQL multi-master cluster setup that uses the Galera Replication Plugin. The replication is synchronous so that any changes happened at any one master node is immediately replicated to other master nodes as broadcasted transaction commits. This synchronization provides high-availability, high up-time and scalability. All master nodes in the cluster are available both READS/WRITES. The Galera Replication Plugin provides automatic node control to implement dropping of failed nodes from the cluster and rejoining recovered nodes back to the cluster. This prevents data loss and clients can connect to any node, as decided by the Replication Load Balancer. Since changes are synchronized between all nodes, unlike conventional replication, there is no slave lag, lost transactions and client latencies are kept at a minimum level.