Web Server Workload

The phenomenal growth in popularity of the World Wide Web (WWW, or the Web) has made WWW traac the largest contributor to packet and byte traac on the NSFNET backbone. This growth has triggered recent research aimed at reducing the volume of network traac produced by Web clients and servers, by using caching, and reducing the latency for WWW users, by using improved protocols for Web interaction. Fundamental to the goal of improving WWW performance is an understanding of WWW workloads. This paper presents a workload characterization study for In-ternet Web servers. Six diierent data sets are used in this study: three from academic environments, two from scientiic research organizations, and one from a commercial Internet provider. These data sets represent three diierent orders of magnitude in server activity, and two diierent orders of magnitude in time duration, ranging from one week of activity to one year of activity. Throughout the study, emphasis is placed on nd-ing workload invariants: observations that apply across all the data sets studied. Ten invariants are identi-ed. These invariants are deemed important since they potentially represent universal truths for all Internet Web servers. The paper concludes with a discussion of caching and performance issues, using the invariants to suggest performance enhancements that seem promising for Internet Web servers. 1 Introduction The popularity of the World Wide Web 1, 22] (also called WWW, or the Web) has made Web traac the