The Tail at Scale – Communications of the ACM
Membership in ACM includes a subscription to Communications of the ACM (CACM), the computing industry's most trusted source for staying connected to the world of advanced computing. Systems that respond to user actions quickly (within 100ms) feel more fluid and natural to users than those that take longer.3 Improvements in Internet connectivity and the rise of warehouse-scale computing systems2 have enabled Web services that provide fluid responsiveness while consulting multi-terabyte datasets spanning thousands of servers; for example, the Google search system updates query results interactively as the user types, predicting the most likely query based on the prefix typed so far, performing the search and showing the results within a few tens of milliseconds. Emerging augmented-reality devices (such as the Google Glass prototype7) will need associated Web services with even greater responsiveness in order to guarantee seamless interactivity. Back to Top It is challenging for service p