代理缓存替换一致性算法的研究  

Research on replacement and consistency algorithm for web proxy cache

作　　者：韩向春[1] 边玮[1] 沈峰[1] 樊书娟[1] 

机构地区：[1]燕山大学信息科学与工程学院,河北秦皇岛066004

出　　处：《计算机工程与设计》2009年第11期2734-2736,2813,共4页Computer Engineering and Design

摘　　要：代理缓存技术能很好的解决Internet发展中出现的访问延迟过长、服务器过载等一系列的问题。针对代理缓存的一致性策略和替换策略还没有很好地结合起来的技术现状,设计并实现了一种新的优化代理缓存的替换一致性算法—RCA算法。这种算法包括一致性策略和替换策略两部分,一致性策略采用自适应TTL机制,替换策略是结合了LFU和LRU,并引入老化机制的LFRU算法。通过Trace-Driven模拟实验,结果表明RCA算法在文档命中率和文档字节命中率比上均优于传统的几个替换算法。With the rapid expansion oflntemet, it has come forth that the delay of access, the heavy loads of web servers and so on. Web proxy caching technique provides a solution to the above problems. Cache consistency policies are not typicaUy well combined with the cache replacement policies and affect the performance of proxy cache accordingly, hence a new algorithm called replacement and consistency algorithm （RCA） is designed and implemented. The algorithm incorporates cache consistency policy with cache replacement policy in which the cache consistency policy is adaptive TTL mechanism, while the cache replacement policy is called LFRU algorithm based on LFU and LRU model, and inducted aging mechanism. Using trace-driven simulation, the results show that RCA algorithm is better than several traditional algorithms both in document hit rate and document byte hit rate.

关 键 词：代理缓存 一致性策略 替换策略 LFRU算法 命中率 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]