Policy:

Since creation of a replica has larger overhead than normal method invocation, it does not always improve performance. Unfortunately, there are no general rules to tell when replication is beneficial, but rather, rules are heuristic and situation-dependent. For example, in product, v2 should be replicated only when it is larger than a certain size. To incorporate such rules, replication mechanism should be flexible so that users can specify their own heuristics. For example, we could have an extended annotation syntax, which accepts an optional expression to decide whether specified objects are to be replicated using run-time values. Our ABCL/R3 allows meta-programming of interpretation of the annotations to cope with such cases.