USENIX Association Proceedings of HotOS IX: The 9th Workshop on Hot Topics in Operating Systems Lihue, Hawaii, USA May 18–21, 2003 THE ADVANCED COMPUTING SYSTEMS ASSOCIATION © 2003 by The USENIX Association All Rights Reserved For more information about the USENIX Association: Phone: 1 510 528 8649 FAX: 1 510 548 5738 Email:
[email protected] WWW: http://www.usenix.org Rights to individual papers remain with the author or the author's employer. Permission is granted for noncommercial reproduction of the work for educational or research purposes. This copyright notice must be included in the reproduced paper. USENIX acknowledges all trademarks herein. Magpie: online modelling and performance-aware systems Paul Barham, Rebecca Isaacs, Richard Mortier, and Dushyanth Narayanan Microsoft Research Ltd., Cambridge, UK. Abstract A B Understanding the performance of distributed systems requires correlation of thousands of interactions be- Event Tracing Event Tracing tween numerous components — a task best left to a com- puter. Today’s systems provide voluminous traces from each component but do not synthesise the data into con- cise models of system performance. Models Models Performance We argue that online performance modelling should be Queries Query Engine a ubiquitous operating system service and outline sev- The diagram shows how requests move through different soft- eral uses including performance debugging, capacity ware components across multiple machines in a distributed sys- tem. Magpie synthesizes event traces from each machine into planning, system tuning and anomaly detection. We de- models that can be queried programatically. scribe the Magpie modelling service which collates de- tailed traces from multiple machines in an e-commerce Figure 1.