Replication and fault-tolerance in the ISIS system

The ISIS system transforms abstract type specifications into fault-tolerant distributed implementations while insulating users from the mechanisms used tO achieve fault-toleram:e.This paper discusses tedmiques for obtaining a fault-tolerant implementation from a now distributed specification and for achieving improved performanc~ by concurrently updating replicated data.The system itself is based on a small set of communication primitives, which are interesting because they achieve high levels of concurrency while respecting higher level ordering requirements.The performance of distributed fault-tolerant services runnin 8 on this initial version of ISIS is found to be nearly as good as that of non-distributed, fault-intolerant ones.