Replication

Replication serves as a safeguard against potential failures, allowing the system to maintain continuity of service even when individual components malfunction or become unavailable.

This aspect of replication has a close relationship with recovery, which will be covered later in this chapter. In short, some replication techniques can prevent system downtime, which requires recovery. Also, some replication techniques enable and enhance recovery processes.

Another aspect of replication is that it can improve system performance by distributing load to multiple nodes, as well as by allowing the system to scale based on traffic.

The copy of the data or running instances is usually called a replica. There are many areas where replication is applicable. Let’s take a look.

Data redundancy

Multiple replicas are distributed across different nodes or servers. If one node fails, the data can still be accessed from the replicated copies on other nodes. It also...