Brief introduction to Performance test _ software test

Load test
A load test is a performance test that indicates whether the data is running in an overloaded environment and the program is able to afford it. By progressively increasing the system load, determine the maximum amount of load that the system can withstand when performance metrics are met.
For a long time not to take over the project performance test, feel a lot of strange, because this time a simple Web page pressure test, suddenly feel that the accumulation of knowledge is not deep enough, can not learn to learn to lose, how to accumulate to become their own is the most important, usually the last forgotten that can only explain or understanding and learning is not profound. Performance testing has always been a difficult part of the testing industry, more important, maybe we all want to do it, but not all have confidence to do it, performance testing is a with a lot of very uncertain factors, because there is no standard answer, can only rely on comprehensive technical ability to analyze, of course, experience is the most important, so we need to continue to explore , accumulation, and even colleagues around to discuss and draw on the experience of many parties.
As for performance, I think most people are very vague about the three concepts and feel alike. There are a lot of instructions on the Internet, but after reading it is easy to forget, and really do project testing when still not clear, this is called uncertainty. So I would like to make a record of the way to deepen the impression, or at least need in-depth understanding. Performance tests, stress tests, and load tests are our most common tests, and for these three kinds of tests, we'll look at an interesting story, which can help us intuitively understand the story, as described below:
A farmer decided to buy a mule, and he thought the mule would have to carry 3 bags of rice at least before he decided to buy the Mule (which is equivalent to the user's performance requirements). As a result, he came to the farmers market, tried a few mules, not suitable, finally have a mule can easily carry the 3 bags of rice, but also chic walk a few steps (this is equivalent to the performance test passed). Then the farmer happily led the mule home, and carried 4 sacks of rice (equivalent to overloading the system), because he ran too far to buy this rare mule, he wanted to see how strong it can be, so the farmer decided to let this mule carry four bags of rice to go home to try, This mule is really bad, at the beginning of the time also a run, but then the road is too far away, the mule more and more laborious (in the case of overload test system can be normal operation for how long, this is equivalent to stress test), fast home, already is two steps to take a step. Finally came home, the farmer is very proud to call out his wife, said: "Wife son, look, see I bought a how powerful mule Ah!", the wife came, the farmer put him and the mule in the way of experience told the old woman, who knows this old woman said: "You are so stupid, so a long way, do not let the mule carry you, Come back like this stupid mule! "The farmer listened and felt very regretful and said," Well, since it did not carry me on the road, let it be made up now, it is also a compensation for me. " "The mule had not yet reacted, and looked at the old farmer dashed, jumped to the back of the Mule (which is equivalent to the limit of the capacity test), the poor mule, in any case, will not think that this hard-hearted farmer after it has been gone for so long, not only did not help it to remove the burden of the body, but also did not give it to drink saliva, Unexpectedly jumped to its already curved back. Poor mule, it's just such a life! I saw the mule, the farmer and the 4 sacks of wheat crashing down together. (equivalent to the system's biggest inflection point, resulting in system paralysis, unusable, capacity test end).
Performance test (performance test)
All the performance related to the test is usually collected and used by different people on different occasions. Test the performance of the software in the system and measure the gap between the system and the predefined target.
Attention points: How much and how fast
Load test: Load test is a performance test that indicates whether the data is running in an overloaded environment and the program is able to afford it. By progressively increasing the system load, determine the maximum amount of load that the system can withstand when performance metrics are met.
The point of concern: how much
Stress test (Stress test): A stress test is a load test under high load, that is, when the system is in a load situation, then continue to pressure him, form a double load, know the system crashes, and focus on the recovery of the system after the crash, a process of prior pressurization, See if the system has been completely destroyed.
There is a very vivid saying: you can bear 100 kilograms of the weight, but also can go, but you can take 100 kilograms of the weight walking 1 months.
I think there is a good description: The external load is called the pressure, the internal pressure is called the load. The load pays attention to the internal and the system itself, while the pressure is more concerned with the appearance of the external system.