集群缓存系统中代理缓存技术的研究

针对集群缓存系统的特点,对其内部各代理缓存进行了详细的研究.在缓存副本的存储方面,采用了面向网站的存储方案,更好的实现个性化服务的功能;在缓存副本的管理方面,采用了将替换和一致性结合在一起的RCA算法,使得整个系统有较高的命中陈旧率;在代理协作方面,通过重定向的方法将请求从未命中的代理转发给缓存了请求的代理,避免了代理之间复制对象,有效地减少了缓存对象的冗余度.通过理论分析推导,证明了它能大大减少访问延迟、有效地减轻了Web服务器的负担.实验证明,本协作方案有较高的命中率.

Research on proxy cache in cluster-based caching system

According to cluster-based caching system, the research on proxy cache is done systemically. The site-oriented cache structure is used to support intelligent process better. A new algorithm called RCA is proposed and designed, which incorporates cache consistency policy with cache replacement policy. It is better than traditional algorithm in hit-staleness. By using redirector, the request will be sent to the peer proxy. Therefore, the redundant duplicates among proxies are greatly reduced and efficient use of the storage of the proxy cache is increased. After analyzed in theory, it is proved that the delay of access time will greatly reduce. It is also proved that hit-rate is higher than ICPS and CRISP in our experiment.