Proceedings 21st International Conference on Distributed Computing Systems (2001)
Apr. 16, 2001 to Apr. 19, 2001
Bhuvan Urgaonkar , University of Massachusetts
Anoop George Ninan , University of Massachusetts
Mohammad Salimullah Raunak , University of Massachusetts
Prashant Shenoy , University of Massachusetts
Krithi Ramamritham , University of Massachusetts
Abstract: Existing web proxy caches employ cache consistency mechanisms to ensure that locally cached data is consistent with that at the server. In this paper, we argue that techniques for maintaining consistency of individual objects are not sufficient-a proxy should employ additional mechanisms to ensure that related web objects are mutually consistent with one another. We formally define the notion of mutual consistency and the semantics provided by a mutual consistency mechanism to end-users. We then present techniques for maintaining mutual consistency in the temporal and value domains. A novel aspect of our techniques is that they can adapt to the variations in the rate of change of the source data, resulting in judicious use of proxy and network resources. We evaluate our approaches using real-world web traces and show that (i) careful tuning can result in substantial savings in the network overhead incurred without any substantial loss in fidelity of the consistency guarantees, and (ii) the incremental cost of providing mutual consistency guarantees over mechanisms to provide individual consistency guarantees is small.
B. Urgaonkar, A. G. Ninan, M. S. Raunak, P. Shenoy and K. Ramamritham, "Maintaining Mutual Consistency for Cached Web Objects," Proceedings 21st International Conference on Distributed Computing Systems(ICDCS), Mesa, AZ, 2001, pp. 0371.