Performance Testing, Load Testing, Stress Testing – Understanding The Difference

By Author: TomWade
Total Articles: 34
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Performance testing is a practical approach of ensuring the quality characteristics of speed, stability and scalability of a software application. It can be further considered as the superset of more critical testing techniques such as load testing, stress testing endurance testing, spike testing and isolation testing. All these methods help to determine that the developed system is meeting its performance criteria.
Load testing focuses on evaluating the response time of the system for transactions for a period of time. This type of testing is carried out to determine the behavior of the system under anticipated load in normal conditions.
Stress Testing is performed in order to evaluate the performance characteristics of an application under test when it is subjected to workload models and load volumes which are beyond anticipation during production operations. It is also performed to determine the application behavior when it is subjected to load volumes while it is subjected to additional stressful conditions such as server failure, insufficient ...
... disk space or limited memory.
Users expect webpages to load as quickly as possible. When this does not happen user satisfaction decreases. Websites that load faster have a competitive advantage. Having competitors just a click away makes it vital to keep load times quick in order to retain customers.
After speed, website scalability is another performance factor. It is important to determine how much a website can be enhanced with new features and configuration so that it can perform equally efficiently with additional enhancements.
There will be times, when a website will have to endure stressful situations like Black Friday, New Years Eve, etc., a time when crashing would not be a good time. Even a few minutes of downtime is extremely costly and may generate invalid records in the database. Stress testing here proves to be very important as they determine the threshold limits of a webpage to help the development team beforehand in addressing such exceptions if and when they occur.
Although many companies are hesitant to do so, the most accurate way to ensure the performance of an application, is to test it in the production system. This can be done by following some practices which can minimize its impact on the real users.
- Test the application sufficiently before making it available to the users at all. This can be planned as a release management plan
- Plan for a scheduled maintenance and restrict all user interaction during that period of time.
- If none of the above two options are possible, then it is best to test the application on the off hours of off days like midnight on Friday, Saturday and Sunday.
- Increase test load on the system gradually, so that the test transactions along with the real user transactions remain within the threshold limits. This will prevent any negative impact on the real users.
Conclusion
With advancement in technology and complexity in software features, performance testing has become more difficult. Part of it can also be attributed to the complexity of modern web browsers and HTML5. The performance metrics after testing should be very clearly informed to the stakeholders. Any defects should be checked and corrections should be immediately made.