On disk caching of Web objects in proxy servers

Abstract

With the increasing popularity of the world wide web, it may be desirable to store copies of popular documents in proxy caches and thus diminish the delay times for URL requests. Web documents have to be treated as indivisible objects for the purpose of caching. In this paper we study the problem of caching web documents on disks. In web applications, the objects are of non-homogeneous size, and this leads to a problem in physical placement in any scheme which tries to emulate LRU. One solution is to use the FIFO scheme which simplifies the disk placement issue, because the order of physical placement can be completely dictated by the order of entry of an object into the cache. In this paper, we show how to achieve a generalization of the LRU policy for the case of caching web documents in such a way that the disk placement and fragmentation issue is handled efficiently.