A Reduced Cache Digest For The Content Representation Of Web Caching

Web Caching can store web object temporarily in order to satisfy repeated web request for the object. Now, the research emphasis is the cooperation of web caching. The technique can shorten latency time; improve web performance and extended capacity. Accordingly, it resolves the scarcity of web bandwidth come with the INTERNET development.The key of web caching cooperation is the representation of caching content. Now, we put forward another means to represent the caching content: Reduced Cache Digest (RCD). RCD has the frequency information of requested objects. It generates digest for each cache server and divides web objects into three groups: recent frequent and unpopular. RCD uses recent and frequent group togenerate digest. In order to build RCD in L7 switch, we research the data structure and update method of RCD. We also research the impact of memory size and grouping proportion on RCD.In order to evaluate the performance of RCD, we build a model of LAN that can access Internet. It has two cache servers, two switches and some client. The NLANR cache trace file simulates user requests. By this model, we first adjust parameters of RCD and CD. To RCD when the proportion of recent group is 37.5%, To RCD when release digest every 1-hour, their performance is the best. After we find the best parameters, we compare the performance of RCD and CD. We find: RCD has more true hit and less false miss than CD, but RCD has more false hit.In short, the performance of RCD is better than CD. Furthermore, RCD doesn't need to release digest between caches that save bandwidth of network.