Performance evaluation for implementations of a network of proxy caches

摘要

In a network of proxy-level caches, such as IRCache (www.ircache.net), nodes collaborate with one another to satisfy object requests. However, since collaboration in current implementations of proxy cache networks is typically limited to sharing cache contents, there may be unnecessary redundancies in storing objects. It is expected that a mechanism that considers the objects cached at every node in the network would be more effective for reducing user delays. In this study we construct algorithms for different implementations of such a mechanism using the theoretical approach of Tawarmalani et al. [Tawarmalani, M., Karthik, K., and De, P., Allocating Objects in a Network of Caches: Centralized and Decentralized Analyses, (2007) Purdue University Working Paper] that investigate caching policies where nodes do consider objects held by their neighbors. The caching implementations are also compared and contrasted with numerical computations using simulated data. The performance results should provide useful directions for computer network administrators to develop proxy caching implementations that are suited for differing network and demand characteristics. There is a significant potential for deploying proxy cache networks in order to reduce the delays experienced by web users due to increasing congestion on the Internet. Therefore we believe that this study contributes to network caching research that is beneficial for Internet users.