.NET Architecture & System Design Interview Question #53

What is database replication?

Database Scaling, Partitioning, NoSQL & Data Consistency Mid-Level Intermediate

Quick Interview Answer

Database replication maintains copies of data on multiple database instances. Replicas may be used for high availability, disaster recovery, geographic distribution, or read scaling.

Detailed Explanation

Database replication maintains copies of data on multiple database instances. Replicas may be used for high availability, disaster recovery, geographic distribution, or read scaling.

Replication can be synchronous or asynchronous depending on the technology and required guarantees. Architects must understand replication lag, failover behavior, consistency, and which node is allowed to accept writes.

Code Example

Primary
  |   |  \ replication
  v   v
Replica 1   Replica 2