MariaDB 10.4 will come with new Galera Replication version 4. This presentation will outline the new features of Galera 4 Replication as present in MariaDB 10.4 and share the early user experiences with it.
Galera is a generic replication plugin, making it possible to deploy synchronous multi-master cluster topologies with database servers supporting Galera Replication plugin API (i.e write set replication, wsrep API) . Currently both MySQL and MariaDB servers have Galera Replication support, and today there are thousands of MySQL and MariaDB based cluster installations, around the world, processing production system loads in bare-metal or cloud deployments.
With Galera 4, MariaDB 10.4 cluster further extends the capabilities of the synchronous Galera replication. The most prominent feature in Galera 4 version, is streaming replication technology, which implements distributed transaction processing within the cluster. With streaming replication, a transaction can be launched to execute in all cluster nodes in parallel. With this, a large transaction can be executed in small fragments due out the transaction life time, and cluster will not choke with the replication of one large transaction write set, as happened in earlier Galera Cluster versions.
Streaming replication works as a foundation for many more features, to be released in short term. e.g. XA transaction support will now be possible thanks to streaming replication technology.