Improving the Efficiency of Object Invocations by Dynamic object Replication

Replication is a technique which is widely used for speeding up access to passive objects. Consistency requirements of distributed object oriented programming languages, however, limit the scope of object replication to coarse grain objects or objects which are modiied infrequently. This is due to the fact that the overhead for global synchronization and preserving replica consistency often outweighs the beneets of local object access. This paper presents an algorithm which dynamically chooses whether an object invocation should be realized either through remote invocation or through ac-cessing a local object replica. The algorithm uses heuristics which consider recent object access patterns as well as the cost for access synchronization and replica conistency. Finally, the results of performance measurements are presented which indicate that dynamic object replication is a feasible approach to improving the eeciency of object invocation in distributed environments.