Sequential Consistency in Distributed Systems

Recently, distributed shared memory (DSM) systems have received much attention because such an abstraction simpliies programming. It has been shown that many practical applications using DSMs require competing operations. We have aimed at unifying theory and implementations of protocols for sequential consistency, which provides competing operations. By adopting concepts from concurrency control, we developed theory for sequential consistency, called a sequentializabil-ity theory. This paper rst presents the sequentializability theory, and then demonstrates the correctness of existing protocols using the theory. Finally, the paper presents a new protocol which requires signiicantly less communication than previously proposed protocols in systems which do not provide hardware atomic broadcasting facilities.