Performance testing that is done once or a few times as part of the system test is not the right approach for many systems that must change and grow for years. Rex Black discusses a different approach--performance engineering--that is far more than performing load testing during the system test. Performance engineering takes a broad look at the environment, platforms, and development processes and how they affect a system's ability to perform at different load levels on different hardware and networks. While load testers run a test before product launch to alleviate performance concerns, performance engineers have a plan for conducting a series of performance tests throughout the development lifecycle and after deployment. A comprehensive performance methodology includes performance modeling, unit performance tests, infrastructure tuning, benchmark testing, code profiling, system validation testing, and production support.

As systems become more complex--serving the enterprise and implemented on the Web and across the Internet-performance testing is becoming more important and more difficult. David Chadwick suggests that the starting point is to design tests that reflect real user activity, including independent arrivals of transactions and varying input data to prevent "cache only" results. David explains how to break down the end-to-end system response time into the distributed components involved in processing the transactions. Learn to use resource-monitoring data to discover bottlenecks on individual systems. By examining the frequency and time spent in various processes, performance testers can determine where resources are being consumed and how to tune a system for better performance.

Whether you are inexperienced with performance testing or an experienced performance tester who is continuously researching ways to optimize your process and deliverables, this session is for you. Based on his experience with dozens of performance testing projects, Gary Coil discusses the ten indispensable tips that he believes will help ensure the success of any performance test. Find out ways to elicit and uncover the underlying performance requirements for the software-under-test. Learn the importance of a production-like test environment, and methods to create suitable environments without spending a fortune. Take back valuable tips on how to create representative workload--mix profiles that accurately simulate the expected production load. And more! Gary has developed and honed these practical and indispensable tips through many years of leading performance testing engagements.

The AJAX model for Web applications has been rapidly gaining in popularity because of its ability to bring the richness and responsiveness of desktop applications to the Web. Because one of the key drivers for the rapid adoption of AJAX is its promise of superior performance, it is surprising that there has been very little discussion of AJAX-specific performance testing. In fact, AJAX has a significant impact on aspects of the performance testing lifecycle including definition of goals, user modeling, and test scripting. Rajendra Gokhale discusses issues to consider: AJAX engine simulation and optimization, cross-client performance of AJAX applications, and design choices related to test scripting. Using Google's "Google Suggest" service as a case study, Rajendra examines the unique challenges of carrying out performance testing of AJAX-based applications and offers suggestions for overcoming them.