High availability with the new Galera Cluster for MySQL and MariaDB
The new Galera Cluster 4 for MySQL 8 is now available, and allows you to increase the availability of your services and applications. Learn about the advantages of the new Galera Cluster in this post.
The release of Galera Cluster 4 for MySQL 8, which includes MySQL 8.0.19 and Galera Replication Library 4.5 with wsrep API version 26, was announced at the end of May.
Among the main features that distinguish Galera Cluster from its competitors are its True Multi-master and synchronous replication features. We present below the pre-Galera Cluster replication process to realize the advantages.
The native replication model
The replication was executed from a Master-Database, which was copied to other Slave-Databases (Master-Slave Model), and since the process was neither synchronous nor fully automatic, there was a Slave-lag effect.
As such, versions of the Slaves tended to differ from Master, which could in some circumstances cause partial data loss and an inefficient failure recovery process, especially in websites and applications with large numbers of database transactions.
The Galera Cluster replication model
Galera Cluster is an open-source software whose function is the replication of MySQL and MariaDB databases, and which allows each new copy of the database to be treated as Master, and synchronized instantly.
This way there is no difference in versions between the different nodes, eliminating the need to perform failover processes (which implies unavailability of services), without the need for intervention.
Advantages of the new Galera Cluster
As an open-source software, Galera Cluster can be implemented in a transparent way, without major changes in the application.
In the new Galera 4 version, one of the advantages is the streaming replication, which makes the replication of large transactions divided into small parts, and applied in small fragments allowing a faster loading.
- There are no failover requirements – the nodes are all active and are all “master” nodes;
- Applications can read and write to any node in the Galera cluster;
- Horizontal scalability, for both reading and writing;
- Synchronous replication, multi-master, active-active;
- Support for adding new nodes to the online cluster;
- Removal of nodes in an agile way;
- Parallel replication;
- No data loss.
Eurotux has extensive experience in critical database administration, and is prepared to implement Galera Cluster in its infrastructure.
