Prefetching and Performance Evaluation of Web Caching Algorithms

Caching is a technique first used by memory management to reduce bus traffic and latency of data access. Web traffic has increasedtremendously since the beginning of the 1990s.With the significant increase of Web traffic, caching techniques are applied to Web caching toreduce network traffic, user-perceived latency, and server load by caching the documents in local proxies. In this paper, analization of bothadvantages and disadvantages of some current Web cache replacement algorithms including lowest relative value algorithm, least weightedusage algorithm and least unified-value (LUV) algorithm is done. Based on our analysis, we proposed a new algorithm, called least gradereplacement (LGR), which takes recency, frequency, perfect-history, and document size into account for Web cache optimization. The optimalrecency coefficients were determined by using 2- and 4-way set associative caches. The cache size was varied from 32 k to 256 k in thesimulation. The simulation results showed that the new algorithm (LGR) is better than LRU and LFU in terms of hit ratio (BR) and byte hit ratio (BHR).