Load testing: types, description of the process

Not every user of a modern computer system in everyday work is faced with the concept of "stress testing". Basically, it is familiar to web developers and all those who use resource-intensive programs. Nevertheless, sometimes knowledge in this matter can be useful to ordinary users. Let's try to figure out why all this is necessary.

Load testing: types and objectives

First of all, it is necessary to clearly distinguish the types of such tests. Conditionally they can be divided into two classes: checking computer hardware with the maximum possible or excessive load on each component and testing the software (websites with forecasting elements, individual programs, etc.).

It goes without saying that site testing is directly related to checking the health of the servers hosting the information, as well as the virtual web servers that are created when working with specialized programs like Denwer.

Load testing programs and their tasks

As you can see, the relationship here is very strong. And if we talk about "hardware", the system of load testing using special tools allows you to accurately identify potential problems when working, so to speak, in extreme situations. An example is the simplest. Modern computer games with their requirements can easily load the system to such a state that it generally ceases to work. Therefore, before installing such software on the computer, you can conduct a series of tests to determine if the filling can "pull" the game. Based on the results, a decision is made to install the program. In principle, the same applies to applications that involve complex mathematical calculations and design work, since the load on the same processor or RAM in comparison with the usual state of the system can be exceeded at times.

As for the second class, testing the site and the server can act as a kind of universal means of predicting their behavior in real-world conditions. For example, it can be emulation of simultaneous access request of a large number of users. As you know, DDoS attacks are acting on this principle when the server or the site does not manage to process too many hits. The load testing of the server or site will be discussed in detail later. In the meantime, let's deal with computer hardware. This applies not only to home or work terminals, but also to real physical server systems.

CPU Test

Let's start, perhaps, from the heart of any computer - the CPU. It's no secret that the malfunctions in his work in most cases lead to the most unfortunate consequences. Very often this is due to overheating. Load testing allows him to create extreme conditions. And then you can see how this will affect his work.

It goes without saying that carrying out load testing of this type implies the use of certain utilities. Today they can count hundreds and thousands. But, according to most experts, the leader in this area is the Prime95 application, which can be applied to both processors and memory slots. But the main direction is the verification of the processor chipset.

When using the utility, it is recommended to close all active applications first and disable the automatic hibernation (sleep) mode so that the computer does not unintentionally disconnect during the scan. Now we need to model the processor the most stringent conditions (and the program can do it like no other, really putting the chips in the most difficult conditions). The test itself is activated from the options menu, where the Torture Test section is selected. There will be indicated the types of operations conducted. The most interesting are Blend tests (simultaneous loading of both CPU and RAM), as well as Small FFT and Large FFT (increasing the load on the processor due to the unloading of RAM).

How to determine that the load testing was successful? There is no common opinion here, but it is believed that if for at least 4 hours of errors or malfunctions the chip was not observed, this component is sufficiently resistant to excessive loads. But it also happens that failures can appear much later, so if you have a fair amount of time, it is better to increase the testing period to 24 hours (errors can appear after half a day of work).

Testing the RAM

No less important is the load testing of the "operative", which performs the functions of the so-called second violin. For this, the Memtest86 + application is best suited, which is by far the best.

To work correctly with it, you need to create a boot disk or a flash drive and load the computer terminal from that media. After activating the test for its full execution, it will take quite a lot of time. You can just leave your computer at night. This should be enough.

Determining the behavior of the graphics adapter

With graphics, too, it is worthwhile to test, because video adapters with excessive load are often the cause of computer failures. The ideal tool here will be the FurMark program.

This utility is able to heat the graphics chip much more than any 3D game with system requirements above the average will do. As practice shows, the conditions are created such that the video card can begin to fail already in the period from 15 to 30 minutes after the start of testing.

In addition, you can use special tools designed for specific games. For example, test applications such as Alien vs Predator, STALKER or something like that are very suitable. As a rule, they are distributed completely free of charge, and with their help you can accurately determine how the system will behave after installing the original game package.

Why you need to test servers and sites

Now a few words about what the testing of the site and the web server is. One aspect (DDoS attack) has already been said. Now we will look at this question from the other side.

The tests themselves of this type to some extent can be attributed even to marketing tools for predicting user behavior. So, for example, you can simulate the behavior of a certain number (max / peak) of people at the entrance to the site, find out how many pages can be viewed, whether e-mail will be used, for example, in the process of ordering goods, how information can be used to identify visitors, will allow is channel capacity to provide simultaneous access to users of the site at any given time, it will demand confirmation of user credentials by a third party (naprime When you enter a credit card number), how effective will be the introduction of Java-applets or using a secure https connection, and so on. D.

The questions of the test of web servers (software) and created Internet resources

In principle, almost the same tasks are set and the server's load testing. However, the emphasis is purely a technical aspect. Tests allow you to determine whether multiple users can have the same IP, specify the response time for sent requests, find out how the whole system reacts to a secure or unprotected connection, what access speed will be if simultaneous sending too many requests, etc. .

In this case (for both the site and the web server), many are advised to use a powerful package called OpenSTA (System Architecture Test), which allows not only to check, but also to break the tasks into components for each individual element of the structure using the tool Creation and simulation of Script Modeler scripts. It is noteworthy that after creating such a model, you can even test the connection over SSL (there must be a so-called name server running). In addition, the results can be saved in the Repository Host section, and the tests can be combined into the appropriate groups.

What in the end?

In principle, this is a very brief information on the issues of load testing, because the tests themselves, as well as the programs that allow them to conduct, you can find a lot. Let's put it this way: the most popular utilities are presented here and the very essence of the issue is examined. It seems that after familiarization, any user at least a little progress in understanding the issues associated with stress testing.