Formal Verification of a Distributed Dynamic Reconfiguration Protocol

Abstract

We present a formal, machine checked TLA+ safety proof of MongoRaftReconfig, a distributed dynamic reconfiguration protocol. MongoRaftReconfig was designed for and implemented in MongoDB, a distributed database whose replication protocol is derived from the Raft consensus algorithm. We present an inductive invariant for MongoRaftReconfig that is formalized in TLA+ and formally proved using the TLA+ proof system (TLAPS). We also present a formal TLAPS proof of two key safety properties of MongoRaftReconfig, LeaderCompleteness and StateMachineSafety. To our knowledge, these are the first machine checked inductive invariant and safety proof of a dynamic reconfiguration protocol for a Raft based replication system.

First two authors contributed equally

References in corpus (3)

• eXtreme Modelling in Practice
• On Symmetry and Quantification: A New Approach to Verify Distributed Protocols
• Towards an Automatic Proof of Lamport's Paxos

Cited by in corpus (1)

• Verification of GossipSub in ACL2s