Slowdown Tolerance

Geo-distributed replicated state machines (RSMs) are at the heart of many production distributed systems, offering linearizability and fault tolerance via consensus protocols. Avicenna is the first consensus protocol for geo-distributed RSMs that maintains low normal-case latency while tolerating a single fail-slow replica.

Replicated state machines are linearizable, fault-tolerant groups of replicas that are coordinated using a consensus algorithm. Copilot replication is the first 1-slowdown-tolerant consensus protocol: it delivers normal latency despite the slowdown of any 1 replica.