Performance Testing
Performance Testing assesses an application on speed or effectiveness of a computer, network, software program or device. In simple terms, performance tests are designed to simulate a particular workload. The workload is defined as the total burden of activity placed on the application. This burden consists of a number of virtual users who process a defined set of transactions in a specified time period. Assigning the proper workload is one of the most crucial parts of any performance analysis. Testing should be conducted to assess performance for three workload categories:
- Steady state - A constant number of users using the application for the entire duration of the test; this primarily examines the application for stress and stability
- Increasing workload - Used to assess the maximum user load the application can take; virtual users are added in steps until the application no longer responds
- Scenario-based - This is designed based on the business users' inputs on typical workloads in a day and is the most realistic test.
The most critical reason to conduct Performance Testing is to identify and remove performance bottlenecks that slow down the application's functions. They typically occur due to application design shortcomings, oversight, bugs, or software incompatibility issues.
When to test Performance?
Different types of performance tests, each focused on different objectives, must be planned and performed throughout the software development life cycle. For example, early design and execution of performance tests will help identify and eliminate performance issues due to design shortcomings. Deferring performance testing to a later stage will prove costly if fundamental design changes are required.
Types of Performance Testing
Different types of performance testing must be planned and executed for an application/product depending on scope/need.
- Load testing helps to ensure the system performs per requirements under the anticipated load level for the purpose of identifying problems in resource contention, response times. It also determines the minimum configuration under which the system can perform satisfactorily.
- Stress testing probes the behavior of the application under very heavy load to determine its capacity limits or to identify limits imposed by the product design or its environment.
- Endurance testing uncovers issues pertaining to non-release of system resources can be identified only when it is run over long periods of time with normal user loads. Endurance Testing helps assess the application's stability over long periods of time.