Introduction to Database Replication

Why databases replicate data, and the reliability and latency trade-offs of copying writes across nodes.

WHY IS REPLICATION NEEDED?

One server = one point of failure. If it crashes, your app goes down.

3 reasons to replicate: 1. High Availability — if one server dies, another takes over. App stays up. 2. Read Scalability — 10 followers = 10x read capacity. Share the load. 3. Low Latency — users in India get data from India server, not New York.

3 ARCHITECTURE - TYPES

LEADER-FOLLOWER (Master Slave)

Leaderless Replication

Multi-Leader Replication

3 COMMIT - TYPES

Semi Synchronous

Asynchronous