Replication Techniques

There are three approaches to conducting replication in a distributed system:

• Single-leader replication
• Multi-leader replication
• Leaderless replication

Let’s explore these replication techniques.

Single-leader replication

Each node storing a copy of the database is called a replica. A database system may have many replicas. With replication, these replica nodes are in sync, and they remain consistent over time.

In single-leader replication, one of the replicas is called the leader. All writes from clients are handled by the leader.

Other replicas are called followers. Followers do not handle writes at all. They keep in sync with the leader and serve read requests to the clients.

Briefly, this is how single-leader replication works: