Combined coherence and prefetching mechanisms for effective web caching

The cache coherence and prefetching are both important mechanisms of web caching. The coherence is for updating the stale documents, and prefetching is for reducing the response latency. Based on the analysis of major algorithms of coherence and prefetching, we have identified the difference and commonness of the two mechanisms. Both mechanisms need the collaboration of proxy client and web server. Therefore, if coherence and prefetching are combined, the number of requests the web server receives will decrease, as well as the corresponding connecting time (e.g. DNS lookup, TCP connection, HTTP head request). In addition, this combination will save the network bandwidth.