Tuxedo: A Peer-to-Peer Caching System

We are witnessing two trends in Web content access: (a) increasing amounts of dynamic and personalized Web content, and (b) a significant growth in “on-the-move” access using various mobile resource-constrained devices by nomadic users. Web caching and the content distribution network (CDN) are popular solutions for improving Web access latency and have the effect of moving content closer to the client. However, these solutions typically do not work well with dynamically generated and personalized content. Transcoding is a popular solution to resolve server-client mismatches (device heterogeneity), but is unable to benefit from caching in general. These trends necessitate revisiting the traditional Web caching and CDN approaches. In this paper, we proposed Tuxedo, a peer-to-peer caching system, that complements to existing hierarchical-based Web caching for efficient delivery of Web content and value-added edge services. Tuxedo allows multiple caches (peers) to efficiently share not only original Web documents, but also computing resources for transcoding (by sharing transcoded versions) and other value-added edge services. The novelty of Tuxedo includes an adaptive neighbor set algorithm for different Web servers, and a hierarchical cache digest for sharing of transcoded versions and value-added services. Together, these two protocols contribute to the scalable and decentralized features of the Tuxedo system.