Google’s Linux cluster currently processes over 150 million queries a day, searching a multi-terabyte web index for every query with an average response time of less than a quarter of a second, with near-100% uptime. In this discussion, Google Fellow Urs Hölzle will describe the software and hardware infrastructure that makes this performance possible, as well as provide an overview of the main problems facing a web search, software architecture, servers and compact rack hardware designs. From the Series:CSE Colloquia - 2002