Replication

Replication is the process of copying data from one database to another. Replication is used to increase availability and scalability of databases. There are two types of replication: master-slave and master-master.

Master-slave Replication:

The master serves reads and writes, replicating writes to one or more slaves, which serve only reads. Slaves can also replicate to additional slaves in a tree-like fashion. If the master goes offline, the system can continue to operate in read-only mode until a slave is promoted to a master or a new master is provisioned.

Master-master Replication:

Both masters serve reads and writes and coordinate with each other on writes. If either master goes down, the system can continue to operate with both reads and writes.