Defect hiding

Load testing uncovers some of the toughest bugs to find and fix, especially because one issue can obscure others. On the user interface, in contrast, you can see multiple problems simultaneously, but that’s not always the case with loading. If your application crashes after 3 days of loading due to a memory leak, that will hide the fact that it also crashes after 4 days due to an ID rolling over. You will need to test, investigate, fix, and release a new build for the first issue before you can start to look for subsequent problems.

Because of this, loading results are often on a measured scale rather than passing or failing. You can measure your Mean Time Between Failures (MTBF) while running under load, which averages the time before a malfunction for any reason. You can then convert the MTBF into a pass or fail result – to pass, load testing must run successfully for more than a week, for instance.

Real-world example – Checking the crash...