What are different characteristics of performance testing?

Performance means a lot more than actually just testing the performance of a software system or application. It covers a wide range of concepts of software engineering and functionalities.

In performance testing, a software system is not merely tested on the basis of its functionalities, specifications and requirements but, it is also tested on the basis of the software system’s or application’s final performance characteristics which are measurable.

- Performance testing is both quantitative and qualitative kind of testing.
- In the field of software engineering, performance testing is typically done to determine the effectiveness and speed of a software system, hardware system, computer or device etc.

- Being a quantitative process, performance testing involves some lab tests like measurement of response time and MIPS (short form for “millions of instructions per second”) at which a software system performs.

- It also involves tests for testing the qualitative assets of a system like scalability, reliability and inter- operability.

- Often performance testing and stress testing are performed conjunction-ally.

- It’s a general kind of testing done to determine the behavior of a system whether hardware or software in the terms of stability and responsiveness when the system is provided with a significant workload.

- It is also carried out to measure, validate, verify and investigate the qualitative attributes of the system like resilience and resource usage.

- Performance testing is a sub category under performance engineering.
- It’s a kind of testing which aims to incorporate performance into the architecture and design of software or a hardware system.
- It’s basically done before the actual coding of the program.

Performance testing consists of many sub categories of testing. Few have been discussed in details below:

1.Stress testing:
This testing is done to determine the limits of the capacity of the software application. Basically this is done to check the robustness of the application software. Robustness is checked against heavy loads i.e., to say above the maximum limit.

2. Load testing:
This is simplest of all the testings. This testing is usually done to check the behavior of the application software or program under different amounts of load. Load can either be several users using the same application or the difficulty level or length of the task. Time is set for task completion. The response timing is recorded simultaneously. This test can also be used to test the databases and network servers.

3. Spike testing:
This testing is carried out by spiking the particular and observing the behavior of the concerned application software under each case that whether it is able to take the load or it fails.

Endurance testing:
As the name suggests the test determines if the application software can sustain a specific load for a certain time. This test also checks out for memory leaks which can lead to application damage. Care is taken for performance degradation. Throughput is checked in the beginning, at the end and at several points of time between the tests. This is done to see if the application continues to behave properly under sustained use or crashes down.

5.Isolation testing:
This test is basically done to check for the faulty part of the program or the application software.

6.Configuration testing:
This testing tests the configuration of the application software application. It also checks for the effects of changes in configuration on the software application and its performance.

Before carrying out performance testing some performance goals must be set since performance testing helps in many ways like:

- Tells us whether the application software meets the performance criteria or not.
- It can compare the performance of two application soft wares.
- It can find faulty parts of the program.