On the scale and performance of cooperative Web proxy caching

TLDR

While algorithms for cooperative proxy caching have been widely studied, little is understood about cooperative‑caching performance in the large‑scale World Wide Web environment. This paper investigates the potential advantages and drawbacks of inter‑proxy cooperation using trace‑based analysis and analytic modelling. The study evaluates cooperation between 200 small‑organization proxies and two large‑organization proxies (23,000 and 60,000 clients) via trace analysis, and extends the findings with a model to project behavior in regions with millions of clients. The results show that cooperative caching yields performance benefits only within limited population bounds, and the model indicates how future Web‑access trends and traffic may affect these benefits.

Abstract

While algorithms for cooperative proxy caching have been widely studied, little is understood about cooperative-caching performance in the large-scale World Wide Web environment. This paper uses both trace-based analysis and analytic modelling to show the potential advantages and drawbacks of inter-proxy cooperation. With our traces, we evaluate quantitatively the performance-improvement potential of cooperation between 200 small-organization proxies within a university environment, and between two large-organization proxies handling 23,000 and 60,000 clients, respectively. With our model, we extend beyond these populations to project cooperative caching behavior in regions with millions of clients. Overall, we demonstrate that cooperative caching has performance benefits only within limited population bounds. We also use our model to examine the implications of future trends in Web-access behavior and traffic.