Hybrid Cache Replacement Policy for Proxy Server

Abstract: As the World Wide Web (WWW) usage has grown exponentially in last two decades, so has grown the recognition that Webproxy caching and Web prefetching techniques play an important role in reducing server loads, client response latencies, network traffic and bottlenecks. The sophisticated combinations of these two techniques cause significant performance improvements of the Web infrastructure and Quality of Service. The heart of a caching system is its page replacement policy, which needs to make efficient replacement decision when its cache is full and a new document needs to be stored. Several replacement policies based on recency, frequency, size, cost of fetching object and access latency have been proposed for improving the performance of Web caching by many researchers. However, it is difficult to have anomnipotentpolicy that performs best in all environments as each policy has different design rational to optimize different resources. In this paper we have implemented Hybrid Cache Replacement policy for proxy server, based on frequency, recency and the prefetch sequence of each object and also proposed the design for an integrated Cache-Prefetching System model which employs the above policy. The simulation results show that our proposed replacement policy performs better than other policies proposed in the literature in terms of Hit ratio, Byte hit ratio and Latency saving ratio.

Keywords: Web caching, Replacement policy, Web prefetching, Proxy Server, Hybrid Cache replacement policy.