• Specify the required performance. Ensure performance objectives are clear. Specify target response times for as much of the system as possible. Specify all variations in benchmarks, including expected response ranges (e.g., 80% of responses for X must fall within 3 seconds). Include benchmarks for the full range of scaling expected (e.g., low to high numbers of users, data, files, file sizes, objects, etc.). Specify and use a benchmark suite based on real user behavior. This is particularly important for multi-user benchmarks. Agree on all target times with users, customers, managers, etc., before tuning. • Make your benchmarks long enough: over five seconds is a good target. Use elapsed time (wall-clock time) for the primary time measurements. Ensure the benchmark harness does not interfere with the performance of the application. Run benchmarks before starting tuning, and again after each tuning exercise. Take care that you are not mea...
