Making Web Servers Pushier

The success of the World Wide Web measured in terms of the number of its users and of the resulting traffic increase is only commensurate to the patience required when sitting in front of one’s computer, waiting for a document to be down-loaded. If one could identify the typical access patterns for a set of documents on a Web server, the server could use or extend the existing protocols to accordingly pre-fetch or push documents to the browsers and proxy servers. In this paper, we present and evaluate a strategy for making Web servers “pushier”. Which document is to be pushed is determined by a set of association rules mined from a sample of the access log of the Web server. Once a rule of the form “Document A → Document B” has been identified and selected, the Web server decides to push “Document2” if “Document1” is requested. The strategy is individual user oriented while not ignoring the aggregate perspective. We evaluate the effectiveness and the cost of such a strategy for two architectures: a two tier “Web server / Web browser” architecture, and a three tier “Web server / proxy server / Web browser” architecture. We consider different settings in the architectures as well as refinements of the strategy taking into account the size of the documents.