Distributed Concurrency Control Performance: A Study of Algorithms, Distribution, and Replication

ABSTRACT- Many concurrency control algorithms have been proposed for use in distributed database systems. Despite the large number of available algorithms, and the fact that distributed database systems are becoming a commercial reality, distributed concurrency control performance tradeoffs are still not well understood. In this paper we attempt to shed light on some of the important issues by studying four representative algorithms-distributed 2PL, wound-wait, basic timestamp ordering. and a distributed optimistic algorithm- using a detailed model of a distributed DBMS. We examine the performance of these algorithms for various levels of contention, “distributedness ” of the workload, and data replication. The results should prove useful to designers of future distributed database systems. 1