Load/Stress Testing

Load and stress testing are two different, but related forms of testing. Stress testing involves testing a system under extreme cases, which will rarely occur under normalconditions. Such testing can involve such scenarios as running many users
concurrently for short times, short transactions repeated quickly, and extraordinarily long transactions.
Load testing places a more realistic load on the system. Scenarios are modelled on the demand that the system is expected to face under real conditions. Load testing starts by placing a low demand on the system, and gradually increasing the load. This process allows measuring the performance of the system under different loads, as well as determining the maximum load that under which the system can respond acceptably.
Load and stress testing are clearly two interrelated processes, generally performed
concurrently.It is important to note what load/stress testing isn’t. They are not functional tests. In order to perform performance testing, it must be assumed that a reasonably stable and functional system is in use, otherwise results are meaningless. With that said, it is still common to uncover functional problems in a system while performing load testing.
However, uncovering excessive functional problems can be a sign of inadequate
functional testing.