Load testing is an important stage of development that allows you to evaluate how the system copes with high load, identify bottlenecks, and prevent failures. There are several types of it, including stress testing and stability testing.

Various tools are used to evaluate performance, including the best gRPC load testing tools for gRPC services, as well as solutions for APIs, websites, and other systems. In this article, we will consider what load testing is, its types, methods, and key stages necessary to ensure the stable operation of systems.

Why Do You Need Load Testing?

Imagine that you launched a new online booking service, and on the first day of operation, the system could not handle the influx of users. Or your application starts to work slower as the number of concurrent users increases. These are the problems that load testing helps prevent.

Load testing is a study of software performance under a certain load to assess its behavior and ability to maintain the expected level of service.

The main tasks of load testing are:

• Evaluation of system performance under different levels of load
• Identification of bottlenecks in the application
• Determination of the maximum load that the system can withstand
• Checking the stability of operation under long-term load

Stages of load testing

The success of load testing largely depends on the correct organization of the process. A chaotic approach can lead to unreliable results or missing critical issues.

Following a clear sequence of stages allows you to not only identify all potential performance issues but also significantly reduce the time and resources for testing. Let’s take a closer look at how load testing is carried out and analyze what specific actions need to be taken to obtain the most useful results.

1. Defining target indicators:

• Collecting information about peak loads (e.g., 1000 users per hour)
• Determining acceptable system response time (e.g., no more than 3 seconds)
• Identifying critical business operations (order placement, payments)
• Agreeing on test success metrics with the business

2. Preparing the test environment:

• Deploying a test environment as close to production as possible
• Configuring monitoring systems (CPU, memory, disks, network)
• Preparing test data (e.g.; product catalog, user profiles)
• Configuring load testing tools (JMeter, Gatling)

3. Developing and testing test scenarios:

• Creating load profiles (e.g.; gradual increase from 100 to 1000 users)
• Writing scripts to simulate user actions
• Conducting pilot runs to validate scripts
• Adjusting scenarios based on the results of pilot runs

4. Conducting load testing:

• Execution of basic testing under expected load
• Gradually increasing load to peak values
• Monitoring all key metrics in real time
• Recording emerging problems and bottlenecks

5. Analysis of results and preparation of recommendations:

• Collecting and processing data on all metrics
• Identifying system bottlenecks (e.g., slow SQL queries)
• Determining the system’s limits
• Preparing specific recommendations for optimization:
• Increasing server capacity
• Optimizing code and queries
• Changing architectural decisions

Types of Load Testing

There are the following types of load testing:

1. Basic load testing is a fundamental check of the system performance under expected load. During such testing, the system is checked to see how it copes with a typical number of users and operations. For example, for an online clothing store, testing is carried out with an imitation of 1000 concurrent users (the average number during sales) who browse the catalog, add products to the basket, and place orders. The page load time, order processing speed, and database response under such load are measured.
2. Stress testing examines the behavior of the system under extreme conditions when the load significantly exceeds the expected one. The main goal is to understand how the system will react to the overload and how quickly it will be able to recover. Imagine a bank payment system that usually processes 100 transactions per second. During stress testing, the load increases to 300 transactions per second. The goal is to understand how correctly errors are handled, whether data is lost, and how quickly the system returns to normal operation after the load is reduced.
3. Stability testing focuses on checking the system under long-term constant load. Its main task is to identify problems that appear over time: memory leaks, performance drops, and failures. When the system is running out of application memory , refer to a full instruction for detailed guidance. In practice, it looks like this: a large company’s CRM system is tested continuously for 72 hours under a load of 500 concurrent users. During the process, resource consumption, speed, and stability of all functions are monitored. If by the end of the test, the system starts to work slower or errors appear, this is a signal of stability problems.

Scalability testing checks how effectively the system can grow with increasing load. This is especially important for cloud services and growing projects. For example, for an online learning system, the load can start with 1,000 concurrent students watching video lessons, with a gradual increase to 10,000.

At the same time, it is worth monitoring how automatic server scaling works, whether the quality of the video broadcast is maintained, and how linearly the infrastructure costs grow.

4. Volume testing is aimed at checking the system’s performance when working with large amounts of data. This type of testing evaluates how the system copes with processing significant amounts of information: for example, how a CRM system works with a database of several million clients or how an online store processes a catalog of hundreds of thousands of products. In this case, not only the speed of the database is checked, but also the performance of all system components: from page loading time to report generation speed.

Conclusion

Load testing helps identify and eliminate bottlenecks in the system, increasing its stability and scalability. Choosing the best tools for load testing, particularly for gRPC, websites, APIs, and other systems, plays a key role in preventing failures. If you are looking for a reliable provider of load testing solutions, then we recommend paying attention to PFLB.