Performance testing and tuning

Baseline is a process of capturing performance metric data for the sole purpose of evaluating the efficacy of successive changes to the system or application. It is important that all characteristics and configurations except those specifically being varied for comparison remain the same in order to make effective comparisons as to which change (or series of changes) is driving results towards the targeted goal. Armed with such baseline results, subsequent changes can be made to the system configuration or application and testing results can be compared to see whether such changes were relevant or not. Some considerations when generating baselines include:

Load testing is the process of putting demand on a system and measuring its response, that is, determining how much volume the system can handle. Stress testing is the process of subjecting the system to unusually high loads far beyond its normal usage pattern to determine its responsiveness. These are different from performance testing whose sole purpose is to determine the response and effectiveness of a system, that is, how fast the system is. Since load ultimately affects how a system responds, performance testing is almost always done in conjunction with stress testing.