Web caching and content distribution: a view from the interior

Research in Web caching has yielded analytical tools to model the behavior of large-scale Web caches. Recently, Wolman et al. have proposed an analytical model and used it to evaluate the potential of cooperative Web proxy caching for large populations. This paper shows how to apply the Wolman model to study the behavior of interior cache servers in multi-level caching systems. Focusing on interior caches gives a di erent perspective on the model's implications, and it allows three new uses of the model. First, we apply the model to large-scale caching systems in which the interior nodes belong to third-party content distribution services. Second, we explore the e ectiveness of content distribution services as conventional Web proxy caching becomes more prevalent. Finally, we correlate the model's predictions of interior cache behavior with empirical observations from the root caches of the NLANR cache hierarchy.