Why do we need Load and Performance Tests
Our expectations for reliable and responsive IT services are increasing, and users are more and more in the driver seat. If applications react slowly to user’s input or are not available, they stop to use those services. Retailer or e-commerce companies are entirely depended on high click rates. Whenever abandon rates go up, it has an adverse impact on their financial revenue. Therefore, successful organizations integrated load and performance tests in their development chain to verify non-functional requirements, size their hardware accordingly and understand the breaking points of their IT services.
The term “90 percent of all user interactions must be below two seconds” is a typical example of a non-functional requirement. Obviously, you can’t test this manually because you need to simulate the expected load and verify the 90th percentile response times for all user actions. A load and performance test will help you to validate such requirements.
Another use case for load tests is to verify the sizing of the actual or required hardware. Companies cut IT costs and can no longer afford oversized machines. CPU and memory utilization during single user activities are typically minimal. In concurrent user situations, this looks completely different. Too high system resource utilization has an adverse impact on response times, and oversized hardware is too expensive. Load tests will help you to find the appropriate sizing.
From an operational perspective, it’s also essential to understand when and how a service starts to deny its function under certain workload situations. There are spiky black Friday load scenarios or permanent high usage figures which could lead to serious issues. The former needs eventually temporary more hardware while the latter has different demands. Load tests are the only measure which gives you insights concerning such critical scenarios.
Load tests are an excellent investment, builds trust in your IT services and gives organizations confidence that the new or changed system performs within the agreed boundaries.