Ensuring the stability and reliability of information systems is becoming an increasingly important task due to the constant growth of competition and the development of technologies. Performance testing as a way to evaluate the stability and efficiency of an IT product plays a key role here. Today, there are four subtypes of such tests: load testing, stress testing, configuration testing, and stability testing. The first two are often confused since they both aim to determine whether the product can handle the load. In this article, you will learn the difference between them, which may be useful if you are looking for a load testing service provider.
What is Load Testing?
Load testing is a test of the system’s performance level under a real or simulated load of the expected volume. That is, such an analysis is aimed at assessing its behavior under predetermined normal and peak loads. Simply put, a load test shows whether a software product meets the non-functional requirements imposed on it: whether it copes with the volume of work for which it is designed; if it copes, then how effectively; if not, then why.
A load test analyzes how a system handles increased load and how quickly and efficiently it processes requests within predetermined parameters. This load can be expressed, for example, as the expected number of users simultaneously performing a certain number of transactions during a given period of time. The main goal of load testing is to obtain information about the response time of the most important business transactions.
Key Features of Load Testing
Since load testing is just one type of performance testing, it is important to understand how it differs from the other three.
Load tests are the simplest form of such testing: they evaluate the operation of the application under the expected load; how it behaves within the norm – the values that it should withstand.
During load tests, the system response speed, throughput, and the use of the server’s computing resources (processor, RAM, network) are analyzed. Determining the maximum performance (maxperf), when the system works quickly and without failures, and peak performance (peakperf), when the system’s performance begins to deteriorate, is also the goal of load testing. Testing often allows you to identify bottlenecks in order to optimize them later to improve overall performance.
So, the main feature of load testing is the expected amount of load that the product being tested is subjected to.
What is Stress Testing?
Stress testing is a method of non-functional software testing aimed at checking the stability and reliability of a system under conditions that go beyond normal operation. Stress tests help to see how an application will behave under overload or external influences. For example, when a database is full, equipment fails, or an attack by intruders. In this case, the goal is to find the limits of the system’s operability, and in addition, tasks are solved to assess its resilience, availability, and quality of exception handling under extreme load. A stress test also evaluates how the system copes with the failure of individual components and whether it is possible to restore their full operation after an overload.
Main Features of Stress Testing
Stress testing as a type of performance testing can be aimed at:
- general study of the system’s behavior under higher than normal loads;
- studying how it handles errors and reacts to exceptional situations under extreme loads;
- identifying bottlenecks under disproportionate loads;
- determining the maximum load value after which the system becomes inoperable.
Stress tests are used to track changes in performance and prepare the product for possible overloads in the future. Unlike load testing, stress testing continues to increase the number of simultaneous requests after the peak point (where performance begins to deteriorate, until the moment when resources are completely overloaded and the system fails). In this case, testers look at how exactly business processes have suffered.
Difference Between Load And Stress Testing
The main difference between load and stress testing is the volume of the load itself: will it be within the expected norm or beyond it?
These two types of tests differ in their goals, methodology, and the nature of the system parameters being tested. Load testing process focuses on assessing the performance of the application and its ability to handle requests under their normal volume. Load tests are conducted to optimize and ensure the efficient operation of the system under real-world conditions.
While stress testing evaluates the behavior of the application under extreme loads that go far beyond the norm. Stress tests help to identify system vulnerabilities and assess the level of its resilience under adverse circumstances.
Use Cases of Load Testing and Stress Testing
The choice between load and stress testing depends on the specific goals, the intended use of the system, and its critical points. If the main interest is to assess performance and overall efficiency, then load testing is a more suitable option. If it is necessary to test the system’s resilience under conditions of overload or abnormal user behavior, it is more appropriate to conduct stress testing.
It is important to consider that load tests are most often conducted in conditions as close as possible to real use cases, while stress tests simulate the most negative scenarios that may rarely occur, but have serious consequences for the business. Determine what task you want to accomplish with testing, and depending on it, select the desired type.
Final Thoughts
Load testing and stress testing are an integral part of the product development cycle and help achieve high levels of performance, stability, and reliability. Load tests help identify bottlenecks and optimize software performance under daily use, while stress tests check their resilience under extreme scenarios. Now you know the differences between the types of performance testing and can choose the right solution to test your system. A combined approach that includes both load and stress testing allows you to create a reliable and efficient product that is ready for any challenges of the modern world. If you are looking for a reliable provider of load testing services, we recommend paying attention to PFLB.
