Glossary term
What is Consensus? Meaning for developers
Getting machines to agree on one value despite failures. Example: Electing exactly one leader.
Learn it properly · System DesignLesson 24: Database Replication: Leader, Follower and BeyondOne database server will eventually die, drown in reads, or be too far from your users. How leader-follower replication works, what replication lag does to real users, why failover is so hard, and how multi-leader and quorum systems handle conflicts.