Differentiated caching of dynamic content using effective page classification

Abstract

As the use of dynamic documents increases, caching dynamic content is becoming an important issue for the usability and scalability of the Web. Dynamic content, which is not retained by current Web caching schemes, is adding significant load to Web servers and network links and hence increasing request response times. This paper proposes a scheme, called eager page dynamic caching (EPDC), to effectively cache dynamic content at proxy servers. The scheme identifies two kinds of dynamic pages, called eager-update pages and lazy-update pages, and uses different strategies to deal with each type. For eager-update pages, the Web server pushes the newest data to the proxy server after updates to the dynamic page content. For lazy-update pages, proxy servers pull the newest data from the Web server when clients request it. We use delta-encoding to decrease the amount of data transferred from the Web server to the cache server. We describe a set of simulation experiments we conducted to evaluate our scheme. We show that our scheme can achieve higher hit ratios and lower network latencies, under a variety of conditions, than both simple delta-encoding and traditional Web caching with the least recently used (LRU) scheme.