Performance testing, or load testing, investigates how well your software system performs under load. Your software may behave differently when there is one user and when there are fifty simultaneous users. I am loath to admit that I worked on a system that locked up when there were five simultaneous users. Hey, it wasn’t my design!

The point is that some errors only manifest themselves when a load is applied to the system. This testing finds things such as deadlock, memory leaks and invalid use of such things as shared memory, semaphores and threads. Any change that could adversely affect performance should be tested.

This week of testing topics continues tomorrow with my discussion of operational validation testing. Don’t miss it!