A scalable Web cache consistency architecture

The rapid increase in web usage has Icd to dramat.ically increased loads on the network infra.st.ructure aud on individual web servers. To ameliorate these mounting burdens, there has been much recent interest in web caching architectures and algorithms. )Veb caching rcduccs network load, server load, and the latency of responses. However, web caching has the disadvantage that. the pages returned to clients by caches may be stale, in that. they may not be consistent with the version currently on the server. In t.his paper WC describe a scalable web cache consistency architecture that provides fairly tight bounds on the st.aleness of pages. Our architecture borrows heavily from the literature. and can best he described as an invalidation approach made scalable by using a caching hierarchy and apl'lication-level multicast routing to convey the invalidations.