Using End-User Latency to Manage Internet Infrastructure

Performance is a requirement for all interactive applications. For Internet-based distributed applications, the need is even more acute — users have a choice about where they browse, and if a site's performance frustrates them they may never return. The goal of this paper is to demonstrate the power of end-to-end latency measurements of actual site traffic for assuring the performance of Internet applications. We briefly describe a system for collecting true end-to-end latency measurements from real site traffic and describe how such measurements can be used to improve user experience. We give examples to show how to use such measurements to evaluate site performance, pinpoint failures, and elucidate capacity issues. We argue that, as services delivered via the Internet become both more widespread and more complex, accurate measurement of site performance is of vital importance for both maintaining and improving end-user experience.