Setting up MariaDB Galera Cluster for High Availability

MariaDB is an open-source relational database management system that is a fork of the popular MySQL database. It is designed to provide high availability and scalability for applications and services that require a highly available database backend.

In this blog, we will be discussing the setup of a MariaDB Galera Cluster, which is a multi-node database cluster that provides automatic failover and load balancing. With Galera Cluster, you can ensure that your database is always available, even in the event of a single node failure.

Prerequisites

• At least three servers with MariaDB installed and configured
• A shared storage system (such as NFS or GlusterFS) for storing the database files
• Network connectivity between all nodes

Step 1: Configure Galera Replication on Each Node

On each node, open the MariaDB configuration file (my.cnf) and add the following lines:

[mysqld]
wsrep_provider=/usr/lib/galera/libgalera_smm.so
wsrep_cluster_address="gcomm://<IP1>,<IP2>,<IP3>"
binlog_format=row
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2

Replace <IP1>, <IP2>, <IP3> with the IP addresses of your cluster nodes.

Step 2: Start the Cluster

On the first node, start MariaDB and initialize the Galera Cluster:

systemctl start mysql
galera_new_cluster

Step 3: Join Additional Nodes

On the remaining nodes, start MariaDB and join the cluster:

SET GLOBAL wsrep_cluster_address = "gcomm://<IP1>,<IP2>,<IP3>";

Step 4: Verify Cluster Status

To verify the status of your cluster, log in to MariaDB on any node and run the following command:

SHOW STATUS LIKE 'wsrep_cluster_size';

The output should show the number of nodes in your cluster.

Conclusion

In this blog, we covered the steps to set up a MariaDB Galera Cluster for high availability. With Galera Cluster, you can ensure that your database is always available, even in the event of a single node failure. Whether you're running a small application or a large enterprise service, MariaDB Galera Cluster can help you achieve high availability and scalability for your database backend.