Viewstamped Replication
Viewstamped Replication is a foundational consensus protocol for building fault-tolerant distributed systems, particularly replicated state machines. It ensures that multiple replicas (servers) agree on a sequence of operations (a log) despite failures, using a leader-based approach with views to handle leader changes. The protocol provides strong consistency (linearizability) and is designed to tolerate crash failures in asynchronous networks.
Developers should learn Viewstamped Replication when building or maintaining distributed systems that require high availability and consistency, such as databases, file systems, or coordination services. It is particularly useful in scenarios where fault tolerance is critical, as it provides a proven theoretical foundation for consensus, and understanding it helps in grasping modern protocols like Raft, which was inspired by it. Use cases include implementing replicated storage, distributed locks, or any service where multiple nodes must agree on state changes.