How to Prepare and Execute Successful Load Testing Campaigns
Load testing is an essential step in the quality assurance (QA) process that helps to ensure the performance and reliability of a website or application. In this article, we’ll explore several practical tips on how to prepare and execute successful load testing.
What is load testing?
Before you begin, it's important to understand the definition and objectives of load testing. Load testing is designed to simulate a high workload on a system, such as a website or application, to measure its ability to handle that load without loss of performance. Load testing can help identify potential bottlenecks and performance issues, as well as determine the maximum capacity of a system.
It is also recommended to perform performance tests as early as possible in the development process. Indeed, the later a performance anomaly is detected, the higher the costs associated with correcting it.
There are several types of load tests, such as ramp-up tests, peak tests, endurance tests, limit tests, stress tests, scalability tests, etc. Each type of test is designed to test a specific aspect of the system, such as the ability to handle a sudden workload increase or a continuous workload over a period. Load testing can be performed manually, but this can be complicated and particularly difficult to replicate. It is therefore advisable to perform load tests using automated tools.
During the planning phase, it is important to consider several factors, such as expected workload, number of concurrent users, frequency of transactions, expected response times, performance objectives and population profiles.
How to Prepare your Load Tests
Preparation is a crucial step for successful load testing. Here are the key steps to follow to prepare your load testing campaigns:
Identify test cases: Test cases define the types of transactions and activities that users will perform on the website or application. It is important to choose scenarios that reflect and/or simulate actual use cases.
Define test requirements and success criteria: It is important to define test requirements, such as the number of concurrent users, frequency of transactions, expected response times, etc. It is also important to define success criteria for load testing.
Configure the test environment (hardware, software, network): It is important to ensure that the test environment is configured correctly and mirrors the production environment as closely as possible in terms of hardware, configuration, software version, rights, data volume, etc., based on the test requirements. This may include software installation, server configuration, test network setup, etc.
Prepare test tools and scripts: There are many load testing tools available, such as JMeter, LoadRunner, Gatling, etc. It is important to choose the appropriate load testing tool based on the testing requirements and the technology to be tested. It is also important to prepare the test scripts according to the test scenarios.
Schedule the date and time of the load tests: Load testing should be scheduled at a time of low traffic to avoid disruptions to actual traffic and to ensure that the test results are accurate.
How to Execute Load Testing
Step 1: Make sure the test environment is ready.
With load testing, it is important to verify that your test environment is ready to handle the determined workload. Make sure your system is properly configured with the necessary hardware and software to run the tests. Make sure your system is connected to a stable network and that all necessary systems (including monitoring/metrology tools) are accessible. It is also important to ensure that the load testing tool is configured and ready to run the tests.
Step 2: Run the test cases
Once your test environment is ready, it's time to run the test cases. Test cases are essentially sequences of simulated actions that users would perform on the website or application. To test them, you need to use a load testing tool that simulates users. Load testing tools are capable of generating a large number of simultaneous requests, thus simulating a real traffic load.
It is important to define the test scenarios in advance based on the needs of your website or application. For example, you can simulate logging in, adding products to a shopping cart, searching for products, etc. You can also simulate different types of users depending on the purpose of the test.
Step 3: Monitor system performance during testing
While you are running the test scenarios, it is essential to monitor the performance of your system in real time. Load testing tools typically have dashboards to monitor performance in real time. It is important to monitor response times, memory consumption, CPU consumption, bandwidth, etc. Real-time monitoring allows you to quickly identify performance issues and more easily identify root causes and react accordingly.
Step 4: Analyze results and identify performance issues
Once the load tests have been run and the results are available, it's time to analyze the data to identify performance issues. The first step is to review the performance metrics for each test scenario. Important metrics may include response time, bandwidth used, data transfer rate, CPU load and memory consumption.
If the results are satisfactory, the load testing campaign can be considered successful. However, if performance issues persist, it is important to quickly identify and correct them. Common problems can include slow response times, server errors, excessive bandwidth usage, or high system resource consumption.
Step 5: Repeat load testing if necessary
The final step in load testing is to repeat the tests if necessary. This may be necessary if performance issues were identified when analyzing the results of the initial test. Repeating load testing can allow your team to confirm that adjustments made to the system have successfully resolved previously identified performance issues and thus improved the system’s ability to handle the tested workload.
When repeating load testing, make sure to use the same test cases, success criteria, and the test environment is configured in a consistent manner. Results from each test should be recorded and compared to identify any performance improvements and to ensure that previously identified problems have been resolved.
By testing and retesting, it is also possible to identify performance issues that result when the system is continuously being used. Load testing can help identify performance problems that may occur when the system is confronted with a heavy workload over an extended period.
Ultimately, repeated load testing is an essential part of optimizing system performance and improving the user experience. By following the same steps of planning, preparing and executing load testing, it is possible to verify that performance issues have been resolved and that the system can handle the workload without experiencing performance problems.
Performance testing is an essential step in the software development process that truly enables organizations to deliver high quality applications. To improve your practices, check out our pre-test checklist that includes 9 items to consider during the test planning phase.