A programming model for service replication in distributed object systems

With the growing emphasis on distributed applications, sophisticated progra mming models for handling replication become important. Control replication as an issue has so far been considered in the larger context of distribute d systems such as ISIS and Arjuna. We present a programming model called Sh adowObjects for programming replicated services to cater to the needs of co ntrol replication in distributed object oriented systems. The ShadowObjects model provides primitives for building highly available and redundant serv ices. Replication in ShadowObjects is encapsulated and a replica access con trol mechanism is provided. Messages accessing the services exported by a s erver object can be captured on-the-fly, and can be appropriately scheduled on the replicas. The ShadowObjects model can be used to develop applicatio ns for distributed systems. (C) 1999 Academic Press.