Implementing Fault-Tolerant Distributed Objects

This paper describes a technique for implementing k-resilient objects–distributed objects that remain available, and whose operations are guaranteed to progress to completion, despite up to k site failures. The implementation is derived from the object specification automatically, and does not require any information beyond what would be required for a nonresilient nondistributed implementation. It is therefore unnecessary for an applications programmer to have knowledge of the complex protocols nonnally employed to implement fault-tolerant objects. Our technique is used in ISIS, a system being developed at Cornell to support resilient objects.