What Is Load Testing? What Tools Are Needed for It?

Stable operation of digital systems under load is one of the most important criteria for their reliability. That is why companies increasingly resort to load testing to identify bottlenecks in advance and avoid failures during peak traffic. The main tool in this process is loading tools, which allow you to reproduce the behavior of many users simultaneously. Today, you can choose from a wide range of solutions: from classic desktop programs to cloud platforms. Particularly convenient are tools that allow testers to run tests in the cloud, such as JMeter in cloud from PFLB.

What Is Load Testing?

Testing allows you to understand how a system will behave under certain conditions even at the stage of creating it. Niche digital products or development for your own needs are usually not designed for a large number of users. Another matter is social networks, government systems, or online stores. They must withstand serious daily loads.

In addition, it is necessary to provide for situations when a huge number of users simultaneously want to access the system. For example, it is important to ensure the stable operation of an online store during big sales. The government services website should not collapse under the influx of parents who want to enroll their children in kindergartens or first grades of schools, etc.

To ensure the reliability and stability of software during peak periods, testers conduct load testing.

Load testing is a test of the stability and performance of software under a load comparable to real conditions of use.

Why Do You Need Load Testing?

Developers use load testing to create conditions as close as possible to the actual expected use of the system, as well as to evaluate its behavior under various load levels.

Load testing allows you to:

• Identify weak points in the architecture of an application or web service.
• Evaluate the load limits at which the system is still able to operate without errors or server problems. For example, limitations in data processing, problems with database performance, or suboptimal algorithms.
• Determine the resources required for trouble-free operation at the early stages of working with the product.
• Evaluate how well the system copes with increased load, i.e., the possibility of scaling it. This is important when planning infrastructure scaling when the number of users is expected to increase in the future.
• Identify potential issues with resource leakage or other instability that would naturally manifest themselves only during long-term operation under intensive load.
• Simulating failures provides an understanding of how well the system is able to recover and continue working after they are eliminated.

Types of Load Testing

There are quite a few types of load testing, each with its own goals and specifics. Load testing itself checks the operability of a system or website under a given load. It can be used to understand whether the system can process the desired number of requests in a certain time. The choice of a specific type depends on the requirements for the system, as well as the planned conditions of its use:

1. Performance testing. It allows you to understand how the system will behave under various conditions. For example, at what maximum number of user requests can it operate quickly, without errors, and at what volume of data do problems start to occur?
2. Stability testing. This is a check of the operability and reliability of the system over a long period of time.
3. Stress testing. It is carried out to check the operability of the system under huge loads — greater than expected under normal conditions. This is important, among other things, for determining maximum loads.
4. Failover testing. Checking the system’s operability in emergency situations. For example, to find out whether the system has switched to a backup server if a failure does occur.
5. Volume testing. This is a test of the system’s stability when working with a large volume of data. It shows how much the performance changes when processing it.
6. Scalability testing. This is a test of the system’s stable operation under an expected increase in load, for example, with a larger number of users or data volume.
7. Server load testing. It allows you to estimate how many users can simultaneously successfully send a request to the server and receive a result.

To ensure the quality of the product at all stages of its life cycle, the tester first of all needs to know this cycle.

Load Testing Methodology

Before starting to test the software product, it is necessary to develop a load testing methodology (LTM). This is a document that describes the entire testing plan, including scenarios for the possible development of the project. LTM is useful for both customers and the team of performers, because it allows you to formalize the requirements and clearly define expectations for the project.

Stages of LTM development:

1. Gathering information about the project. Defining the goals and objectives of testing. Setting restrictions and creating rules for modeling the system.
2. Compiling a list of known and possible errors, as well as their causes. Defining the technical and software characteristics of the test environment. Description of product requirements.
3. Direct testing. Detailed description of the verification stages. Compiling the results of the load testing and formulating recommendations based on its results. Description of the expected vulnerabilities, as well as ways to solve problems

Load Testing Software

Load testing is performed using special programs. Some of them are free, open source, while others require payment. Here are the main ones:

Apache JMeter

Among the advantages:

• Free, open source.
• User-friendly interface for easy test creation.
• Supports a wide range of protocols.
• ​Can be used for functional testing.

Explore the features and benefits of JMeter in the Cloud on the PFLB website.

LoadRunner

Among the advantages:

• Excellent means of results analysis.
• Supports many protocols and technologies.
• Allows you to scale load tests to a large number of virtual users.

Gatling

Among the advantages:

• Lightweight, high-performance.
• Suitable for testing highly loaded systems.

Vegeta

Among the advantages:

• Easy to use, quick to set up.
• Easily integrated with CI/CD systems.
• Supports testing of microservices, APIs.

Conclusion

Choosing the right tool for load testing plays a key role in ensuring the stability and performance of IT systems. Modern loading tools allow not only to accurately model user behavior, but also to flexibly configure test scenarios depending on the goals of the project. At the same time, popular cloud solutions like JMeter provide additional convenience and scalability. If you need such modern, effective tools for testing, we recommend paying attention to the company PFLB.