Performance testing
Is your application slower than the last release? Some services, such as web servers, have relatively low resource requirements and are unlikely to be constrained under normal circumstances. Other applications will hit the limits of the available network, disk access, memory, or processing. You will see symptoms such as increased latency on operations or rising failure rates, which indicate that your system cannot maintain this level of activity.
Programs tend to become larger and more complex over time, which always carries the risk of slowing them down. Whatever limits your system is hitting, part of testing is to ensure that this release doesn’t accidentally have lower performance than the last.
Real-world example – The accidental load test
In a company that provided SMS text message infrastructure, I was onsite to perform user acceptance testing with a large customer. We worked through the test plan, successfully demonstrating all the...