A programming model for service replication in distributed object systems

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