Using multisource replication

A familiar replication topology is one where we have a single master server and several slave servers. Another alternative topology is where we have a single slave server connected to multiple master servers. This is called multisource replication.

Getting ready

For this recipe, we'll be working on the assumption that we have three servers, db01, db02, and db03, which are each running a fresh install of MariaDB. The first two will be our replication masters, and the last one will be our replication slave as shown in the following diagram:

We'll further assume that all three servers are on the same subnet, 192.168.4.0, with the final part of their individual IP addresses being 101, 102, and 103, respectively.

How to do it...

1. On all three servers, launch the mysql command-line client and run the following command to add our replication user:

   GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.*
     TO replicant@'192.168.4.%' IDENTIFIED BY 'sup3rs3kr37p455w0rd';
   

2. Quit the...