基于对象角色的高精度缓存替换算法*

现有的Web缓存器的实现主要是基于传统的内存缓存算法，由于Web业务请求的异质性，传统的替换算法不能在Web环境中有效工作。研究了Web缓存替换操作的依据，分析了以往替换算法的不足，考虑到Web文档的大小、访问代价、访问频率、访问兴趣度以及最近一次被访问的时间对缓存替换的影响，提出了Web缓存对象角色的概念，建立了一种新的基于对象角色的高精度Web缓存替换算法(ORB算法)；并以NASA和DEC的代理服务器数据为例，将该算法与LRU、LFU、SIZE、Hybrid算法进行了仿真实验对比，结果证明，ORB算

High-precision cache replacement algorithm based on object role

Currently, the implementation of Web caching is mostly based on traditional cache updating algorithms. However, due to the diversity of the Web traffic pattern, the traditional algorithms for cache updating can not be used in Web environment effectively. This paper studied the basis of Web caching replacement operations, and analyzed the deficiency of previous replacement algorithm. As the size, the access cost, the access frequency and the recently visiting time of Web document affect caching replacement, proposed the concept of Web caching objects roles. Created a new high accuracy Web caching replacement algorithm (ORB algorithm) based on objects roles. In case of NASA and DES proxy server data is used for example, and compared the algorithm with LRU, LFU, SIZE, Hybrid algorithms. The result shows that ORB algorithm has better performance than the others.