We talk about the Master Slave replication strategy for reliability and data backups. This database concept is often asked in system design interviews with discussions on consistency and availability tradeoffs.
Very closely tied to the master slave architecture is the concept of distributed consensus. When designing a system, we must make sure that the individual components can agree on a particular value. (Leader election, distributed transactions, etc…) Some popular techniques are 2 phase commit, Multi Version Concurrency Control, SAGAs and Quorum.
0:00 Problem Statement
1:24 Synchronous replication vs. Asynchronous replication
3:36 Peer to Peer data transfer
4:44 Split brain problem
Also useful when used with Master Slave replication is sharding. You can check out the video mentioned below.