What is the difference between replication mechanisms and the master server in a database?

In a database, the main server (master) is the primary node that handles all write operations (insert, update, delete). It is responsible for transaction processing and maintaining data integrity.

Replication is the process of copying data from the main server to one or more subordinate servers (replicas). Replicas are typically used for load distribution on reads, increasing fault tolerance, and backup.

Main differences:

• Role: the main server handles writes, replicas handle reads.
• Synchronization: replicas receive updates from the main server, usually with some delay.
• Load: replicas offload the main server by handling read requests.

An example in the context of Golang — when working with a database, you can configure a connection pool so that write requests go to the main server, and read requests go to the replicas.