In Software Development, we put the system through different types of testing ahead of release to ensure the product meets stakeholder and designer requirements. Stress testing is one type of test to use.
What is stress testing? We use stress testing to check how well a system responds to normal and abnormal conditions or unusually high traffic. The method aims to anticipate anything unexpected while the user engages with the product that could cause the software to malfunction or fail. Finding potential flaws allows developers to make corrections, enabling the software to be more robust when under stress and recover faster.
Stress testing also helps test infrastructures. For example, a lot of projects now deploy auto-scaling infrastructure. Stress tests enable them to identify issues or probable failures that could happen when a load increases before the issue can cause problems in production.
Key Objectives of Stress Testing
While stress testing’s main objective is to help understand how an application behaves when it hits extreme conditions, it is equally important to be clear on what one needs to focus on while conducting the tests.
What to test in Stress Testing?
Stress testing helps determine how the application behaves when exposed to extreme conditions. Let’s take a look at some of the essential inquiries to make:
- Does the system crash entirely, or can it still function as expected without any intervention if it throws an error?
- Can the system automatically recover following a crash, and if it does crash, how long does it take to recover?
- How well do the data saving mechanism work during and after a crash?
- Look for the exact failure point and what causes the failure.
- If the system fails, check for security lapses and weaknesses.
- Are there any memory leak problems, and is the memory released when the program no longer uses it?
- Examine data integrity after a crash, and if data becomes corrupted, does it still exists in a usable state?
- Make sure that the system reports errors correctly upon any failures.
Some Examples of Extreme Conditions
Stress testing pushes the system to its extreme capacity and then checks the response. The level of extreme and type of stress test used depends on the nature of the application under test. A key to successful testing is to determine the most valuable scenarios to use:
- Users – Set a varied and maximum number of users that will access the application concurrently.
- Resources – Actively load the memory and disk space beyond capacity.
- Data overload – Create a large data insertion beyond the accepted level or database unavailability.
- Server and network connections – Testing with multiple client connections and introducing intentional connection failures.
- File size and usage – Accessing the same file by numerous concurrent users or accessing a huge file.
Planning and Reporting
The two most important components of stress testing are a well-laid test plan and a comprehensive report generated at the end of the session.
Before starting, the test’s goal needs to be clearly understood. Then, the objective, scope, selected tools, and timeline must be clear by the planning phase.
Using automation tools during stress testing makes the process more efficient, faster, and straightforward. Thus, tools are often a preferred method. There are also load testing tools that can run the test using many concurrent users. In addition, tools offer excellent reporting and metrics. Different kinds of metrics represent the output of a stress test and can help analyze and determine the application’s state and any desired changes.
Some Examples of Stress Testing Metrics
- Concurrent Users – Provides information about the number of active virtual users accessing the application simultaneously.
- Average Response Time – Information about the time taken for the data to move from one point to another and vice versa. These metrics help determine how the application behaves with different load and network conditions.
- Throughput – A measurement of the amount of data that flows back and forth, i.e., the total request a system can handle, measured in kilobytes per second.
- Error Rate – Stress testing aims to capture failure points and errors. It is essential to know the percentage of errors encountered during the test.
The issues raised after successful stress testing don’t always need a code-level fix because they can also be addressed outside the code by changing the configuration and upgrading hardware.
Stress testing plays an essential role in software development like all other tests. It’s a beneficial analysis for developers since it quickly assesses what’s not working correctly and will need a fix or upgrade.
Stress testing is not listed as part of the preliminary list of testing because not all applications require it. When the system runs smoothly, no one cares about performance. Still, when the system expects a sudden surge in traffic, it’s good practice to run through stress testing to understand the reliability and stability of the application when it hits unexpected circumstances.