Using checkpoints to localize the effects of faults in distributed systems

A checkpointing scheme can be used to ensure forward progress of a computation (program) even when failures occur. In a distributed system, many autonomous programs can execute concurrently and obtain services from a set of shared servers. In such a system, it is desirable to to restrict a checkpoint or rollback operation to a single program to localize the effects of failures, even when processes of different programs communicate with servers. This can be achieved by a scheme based on message logging and consistent checkpoints when the system is deterministic. When the system (communication network or programs) is nondeterministic, the semantics of the server functions should be exploited to reduce the additional synchronization that needs to be introduced to ensure locality. The authors illustrate this by presenting efficient algorithms for a file server that do not require the logging of messages on stable storage