Object-based protocol for replicated objects

Objects support abstract methods in object-based systems. We discuss a novel object-based locking (OBL) protocol to lock replicated objects by extending the quorum-based protocol handling read and write requests to abstract methods. Unless two methods op/sub 1/ and op/sub 2/ conflict, the quorum sets of the methods may not intersect even if op/sub 1/ and op/sub 2/ update the replicas. Here, a pair of replicas A and B compute op/sub 1/ and opt, respectively. If op/sub 1/ and op/sub 2/ do not conflict, A and B can later compute op/sub 2/ and op/sub 1/, respectively. We newly propose a version vector to identify what methods are computed on a replica. We discuss the OBL protocol where the replicas exchange the compatible methods by using the version vector.