The content and access dynamics of a busy Web server: Findings and implications

In this paper, we studythe dynamics of one of the busiest Web sites in the Internet today. Unlike many other efforts that have analyzed client accesses as seen by proxies, we focus on the server end. We analyze the dynamics of both the server content and client accesses made to the server. The former considers the content creation and modification process while the latter considers page popularityand localityin client accesses. Some of our keyresults are: (a) files tend to change little when they are modified, (b) a small set of files tends to get modified repeatedly, (c) file popularity follows a Zipf-like distribution with a parameter α that is much larger than reported in previous, proxy-based studies, and (d) there is significant temporal stabilityin file popularitybut not much stabilityin the domains from which clients access the popular content. We discuss the implications of these findings for techniques such as Web caching (including cache consistencyalgorithms) and prefetching or serverbased “push ” of Web content.