There are at least five distinct paradigms for replication: Group Communication [0], Viewstamped Replication [1], MultiPaxos [2], Raft [3], and Shared Logs [4]. In a previous post, I did a deep-dive on MultiPaxos, showing that it implements a specific abstraction: State Machine Replication or SMR. The SMR API allows servers to propose commands and play them back in a durable total order:
