Probabilistic Data Consistency for Wide-Area Applications H. Zou, N. Soparkar, and F. Jahanian   View Paper (PDF)   Return to Internet, Performance, and Systems Management Abstract A growing and diverse range of wide-area applications rely on distributed data management services which often employ data replication to meet availability and response time constraints imposed by the target domains. Since many of these applications can tolerate some staleness in the data they access, the constraints may be better met by exploiting relaxed data consistency among copies in the system. However, in the current Internet architecture, it is nearly impossible to provide deterministic guarantees for the bounds on data inconsistency among copies. We present an approach for providing probabilistic data access guarantees while maintaining availability and timing predictability. Our proposed service, which can be superimposed on traditional replication schemes, guarantees with a certain probability that the value returned to satisfy a client request will be temporally consistent with the newest copy of the same object in the system. We also include a discussion on a Solaris-based implementation of the proposed probabilistic data access service, and present a performance evaluation of its implementation on a prototype replication layer. Keywords: wide-area applications, replication, temporal consistency, probabilistic consistency, deterministic guarantees DiSC'01 Copyright ©2002 ACM Inc.