Parameterized Model Checking of Synchronous Distributed Algorithms by Abstraction

Parameterized verification of fault-tolerant distributed algorithms has recently gained more and more attention. Most of the existing work considers asynchronous distributed systems (interleaving semantics). However, there exists a considerable distributed computing literature on synchronous fault-tolerant distributed algorithms: conceptually, all processes proceed in lock-step rounds, that is, synchronized steps of all (correct) processes bring the system into the next state. We introduce an abstraction technique for synchronous fault-tolerant distributed algorithms that reduces parameterized verification of synchronous fault-tolerant distributed algorithms to finite-state model checking of an abstract system. Using the TLC model checker, we automatically verified several algorithms from the literature, some of which were not automatically verified before. Our benchmarks include fault-tolerant algorithms that solve atomic commitment, 2-set agreement, and consensus.