MariaDB replication is a mechanism that permits us to replicate data to another instance on another host. Replication is generally used for the following reasons:
Scale out reads: Replication permits scaling between several read databases to grow the read capacity
Providing high availability: With multiple slaves, you have no read Single Point Of Failure (SPOF)
Data analysis: Replication can be useful to have a replicated environment to allow querying without impacting the production environment
Disaster recovery: You can have a distant copy of a master if a major issue occurs on your primary site
Security: Replication can be used to add a read-only database on a DMZ for example
Replication works in an asynchronous mode, which means, if you have a low or degraded bandwidth, you will have a replication delta (slave late/with more delay) depending on your write load. The more write queries you have, the more information will need to be replicated and the faster...