An article that takes you in-depth understanding of what a load test

Introduced
When any software development project is nearing completion, it may have passed numerous tests, especially in the context of testing and development of simultaneous agile testing. No matter how many rounds of testing you have, once your application is nearing completion, there is only one way to know if your software can meet the real needs of the real user base, which is the load test. You can use the Load test tool to do the work. load testing is the process of adding simulation requirements to a software, application, or Web site to test its operational status in different environments.

load testing and performance testing
As one of the most well-known and most common types of performance testing, load testing involves applying conventional pressure to a software application or IT system to see if they can perform as expected under normal conditions. The load test ensures that, in a given parameter range, the program or system does not exceed the processing power of its intended design, while the stress test is about overloading until the system crashes, the application cannot run, or the load scenario is less likely to occur. Both test methods play an important role in verifying that a given front-end software such as a Web site, a backend system, such as the Apache server hosting the site, can handle the real load well. stress tests deliberately induce failure so that you can analyze the risks involved in the breakout, and then perhaps you will choose to adjust the scheme so that they are more gracefully broken. Stress testing is valuable in preparing for emergency situations and in determining the maximum load carrying capacity of a given system performance. However, when it comes to simply ensuring that a software application or a physical network can normally host user requests and actions, load testing is the right way to accomplish a task.

Of course, it should be noted that if your application is not doing well, then this means that the load test before release will become a stress test after it is released . Read our load test best practices to avoid these common pitfalls. Once the load starts causing a crash, from that moment on, by definition, it becomes a stress test. This is the main reason why load tests and stress tests are often confused, because the exact same test may change from a load test to a stress test in some cases.

Understanding Load Tests
A load test is a simulated environment that is as close as possible to a finished product deployment and created in the user base for an application or system. by leveraging Professional test software, load testing allows the development team to answer the question "Does my system run as expected in these environments?" "Does it perform well enough?" "As the Microsoft Application Performance Testing guide says: A load test can measure response time, throughput, and resource utilization, and determine the performance bottlenecks of the application, assuming that the bottleneck is lower than the peak load."

Here, "below load peak" again simply indicates that the load test parameters fall within the range of the stress test (defined as the health of the test system at or above the maximum load). Load tests can detect system delays, page loading problems, and when multiple users access an application or high concurrency causes the system to crash, and such problems are easily overlooked in development and test environments even if the code has been checked many times. When hundreds of thousands of people visit the software at the same time, some undetectable problems may suddenly occur.

For example, suppose you are developing a new online voting platform and expect it to withstand 10,000 user submissions per minute during peak load times. During the development of the software, you may have performed unit tests, Periodic regression tests, to ensure that no existing functionality was broken in the new feature development process. But when did you start doing large-scale user testing? When do you start testing programs that accept hundreds of overlapping field items, form submissions, and other commands?

technically speaking, at the end of a project's production, a load test with real user involvement that accurately simulates system performance is performed . This is similar to car production: You can repair and test the engine, but if the engine is not installed, you cannot test the car's performance on the road. In fact, early in a software development project, you can test the load of a particular component in a centralized way, such as testing back-end performance issues, user input, endurance entered during an extended period of time, or any other way to put pressure on the system, causing delays, memory leaks, or feature crashes. That means you're already carrying out a load test, just in a restricted form, and already exploring the impact of multiuser access on the system. A few user input tests on an incomplete system, performance test expert Scott Barber, one of the co-authors of Microsoft resources, is more likely to call it "multi-user functional testing." "Again, the right load test requires an almost complete system, and often requires the use of test software that can realistically simulate thousands of of users.

But there is an exception to all the rules. There is a clear multi-user problem for Internet applications, from GPS applications of smartphones to online multiplayer video games, where load testing can be done on the system without having to pass through many users because multiple users are not the only possible source of load. Sometimes the load may be caused by large files, a large number of computations, or even a weak network connection. Think about opening a PDF in Acrobat, or opening a PSD in Photoshop. The load is generated when the system encounters pressure. Is it fast enough to execute open files? Will the application crash if the file is too large? What criteria do you use to determine if your application is "fast enough" to open the file? It is acceptable to open the file, but what if it takes 5 minutes? Who has developed the ideal load-carrying capacity of the system standards, and based on what? What is the boundary between the user's subjective preferences drawn by the load tester and the system's goal function?

To be a good load tester and to analyze load test results, you often need to have more than the software engineering and testing expertise to be familiar with the user experience.

* * The future of load testing: Understanding what users really think
The ultimate purpose of load test tools and performance testing tools is always to reduce risk, whether it is the risk of software success features, end-user perceived risk, or risk to the company's bottom line. Of course, all of these three are tightly intertwined, so it's important for a developer or tester to know how they relate to each other. To be bold, if you focus on reducing intermediate standards, then user perception and two other factors will usually come naturally. The problem with many load tests boils down to user perception rather than the ideal page load time and other technical statistics.

In fact, while repeated load testing often requires specialized software, data interpretation is not as simple as it seems, due to the existence of human complexity factors. For example, if someone comes to a Web site that is only loaded, then the user expects it to load immediately, even if it's a two-second load time, but if they want to load the embedded video, the user will be more tolerant of the response time. The advent of the broadband era, we have gradually become accustomed to receive these. With the psychology of the user experience more in-depth exploration, found a lot of subtle details, in fact, people are more inclined to the site access speed evenly consistent slow, for example, the overall load faster, but there is an internal speed inconsistent mentality. Therefore, there is no such psychological level of cognition, really understand the user's wishes and expectations, and then more load test data will not be the greatest perceived effect to automatically help you improve the software.

In other words, if you do not understand human psychology, user behavior, and reactions, you will not be able to achieve a very real load test, and, worse, you may misunderstand the results of the test. This is why it is important to simulate the real end user experience as much as possible when performing a load test, repeatedly simulating a user's access to a website or application when approaching the maximum load, analyzing the test results, and then making the system as best possible to reduce the unpleasant factors in the user experience. As the development cycle becomes shorter, software companies can save time and money by simply focusing on specific failures to make the user experience smoother and more efficient, rather than solving all the problems that are encountered under high load conditions.

This article was compiled by OneAPM Zhang Yu from the Smartbear website of the article "What is LOAD testing?"
This article was transferred from OneAPM official blog
Original link: https://smartbear.com/learn/performance-testing/what-is-load-testing/

Click here to apply for free OneAPM cloud pressure performance test software trial

An article that takes you in-depth understanding of what a load test