Popularity-based partial caching for VOD systems using a proxy server

Abstract

In this paper, we propose a PPC (Populari@-based Partial Caching) scheme for continuous media objects on the proxy servers. In this scheme, either the initial portion or the entire blocks of objects are cached and the size of the initial portion of each stream varies with the popularity of that stream. Under the proposed scheme, the initial latency otherwise happens to access the requested objects from the remote server can be reduced signijlcantly and moreover, the limited cache storage space can be utilized ef~cient~. Considering the characteristics of continuous media objects, we also apply the popularity of each stream by taking the amount of the data of eac~~ stream played back by clients into consideration. As a result of trace-driven simulations with 9 days of log jiles for VOD server, which were obtained from the website http://imbc.hananet. net, we show that, PPC, our proposed caching scheme, outperforms other well-known caching schemes in hit ratios and replacement overhead.