A basic MySQL or MariaDB replication arrangement uses a simple method to perform replication. Any changes to schema or data on the master are recorded in its binary log. The slave regularly asks the master for any new entries to its binary log, based on position numbers in that log. The slave will record any new entries the master sends it in a relay log and then execute them on its copy of the databases. This system works well with a straightforward master-slave configuration, when there is only one master and one or more slaves.
With recent releases of MySQL and MariaDB, a slave can have multiple sources for replication. This may seem absurd at first until you consider one of the inherent points of replication: load balancing. Slaves are typically used for Read load balancing—to spread traffic related to SELECT statements among several servers. With multi-source replication, Writes can also be load balanced. For a large organization with …[Read more]