Primary-Backup Replication Algorithm

Primary-backup replication

Primary-backup replication is a technique where we designate a single node amongst the replicas as the leader, or primary, that receives all the updates.

This technique is also known as single-master replication.

We commonly refer to the remaining replicas as followers or secondaries. These can only handle read requests. Every time the leader receives an update, it executes it locally and also propagates the update to the other nodes. This ensures that all the replicas maintain a consistent view of the data.