Using transaction isolation levels for ensuring replicated database consistency in mobile computing environments

摘要

Replicating databases over several servers is an efficient strategy to improve data availability and to increase transaction throughput rate. However, due to inherent limitations of mobile and other loosely-coupled environments, the replica control protocols responsible for ensuring replicated database consistency should be revisited. This paper proposes a new replica control protocol which guarantees the consistency of replicated databases in a mobile computing environment. The key benefit of the proposed protocol is to ensure consistency by means of the notion of transaction isolation levels without the use of a locking mechanism. Thus, a user may trade the degree of replica consistency for a potential increase in data availability and transaction through-put rate. The proposed protocol uses a read-any/write-any approach and reduces the number of messages exchanged among the replicated servers. Experimental results show the potential efficiency of the proposed approach.