Obtaining the optimal cache document replacement policy for the caching system of an EC website

Adopting a proper cache document replacement policy is critical to the performance of a caching system. Among the existing cache document replacement policies, no one policy can surpass all the other policies in every case. Besides, the most suitable cache document replacement policy for a caching system is often chosen from the existing policies, which cannot guarantee the optimality of the chosen policy. These phenomena motivate us to construct a cache document replacement policy which content can be tailored to the specific requirements of a caching system. In this study, the optimal linear combination (OLC) cache document replacement policy tailored to the requirements of the caching system is to be found out. To evaluate the effectiveness of the proposed methodology, an experimental EC website has been constructed, and the log file of the website server was used as the data source to evaluate the performances of various cache document replacement policies under different cache sizes. In our simulation experiments, the OLC policies outperformed the other traditional policies by increasing the hit rate and the byte hit rate up to 7% and 11%, respectively.