PCR: caching replacement algorithm in proxy server

The efficiency of caching is a key factor affecting the performance of content delivery network (CDN). The main aim of current CDN caching is to obtain a higher hit ratio, since the validation and freshness of outdated pages have not received due consideration in their replacement model. In this paper, a new improved cache profit model is clearly defined, and the freshness factors of web pages have been taken into adequate account. Based on the profit model, a new replacement algorithm – proxy cache replacement (PCR) – is recommended, and it can be proved optimal under the rational hypothesis. To conclude, a series of comparative experiments verified the efficiency of PCR in web caching replacement.