What is replication in data storage systems or databases?

Replication in data storage systems and databases is the process of copying and maintaining identical data across multiple servers or nodes.

Goals of replication:

• Increased fault tolerance: if one server fails, data remains accessible on another.
• Load balancing: read requests can be distributed among replicas.
• Data localization: replicas can be located closer to users to speed up access.

Depending on the architecture, replication can be synchronous (writes are confirmed on all replicas) or asynchronous (writes are confirmed immediately, replicas are updated later).

An example in Go is using a library for database operations that supports replication, or implementing replication logic between nodes using channels and goroutines.