Organization-Based Analysis of Web-Object Sharing and Caching

Performance-enhancing mechanisms in the World Wide Web primarily exploit repeated requests to Web documents by multiple clients. However, little is known about patterns of shared document access, particularly from diverse client populations. The principal goal of this paper is to examine the sharing of Web documents from an organizational point of view. An organizational analysis of sharing is important, because caching is often performed on an organizational basis; i.e., proxies are typically placed in front of large and small companies, universities, departments, and so on. Unfortunately, simultaneous multi-organizational traces do not currently exist and are difficult to obtain in practice. The goal of this paper is to explore the extent of document sharing (1) among clients within single organizations, and (2) among clients across different organizations. To perform the study, we use a large university as a model of a diverse collection of organizations. Within our university, we have traced all external Web requests and responses, anonymizing the data but preserving organizational membership information. This permits us to analyze both interand intra-organization document sharing and to test whether organization membership is significant. As well, we characterize a number of parameters of our data, including basic object characteristics, object cacheability, and server distributions.