Optimistic Recovery in Distributed Systems

Optimistic Recovery is a new technique supporting application-independent transparent recovery from processor failures in distributed systems. In optimistic recovery communication, computation and checkpointing proceed asynchronously. Synchronization is replaced by causal dependency tracking, which enables a posteriori reconstruction of a consistent distributed system state following a failure using process rollback and message replay. Because there is no synchronization among computation, communication, and checkpointing, optimistic recovery can tolerate the failure of an arbitrary number of processors and yields better throughput and response time than other general recovery techniques whenever failures are infrequent. © 1985, ACM. All rights reserved.