What is the difference between performance tests, load tests, and stress tests?

Performance testing (or multiprocessing user concurrency performance testing), load testing, strength testing, and capacity testing are some of the areas of performance testing, but concepts can be easily confused. A few concepts are described below.

Performance test (performance Test): Generally collects all the performance related to the test and is usually used by different people in different situations.
Focus: How much and how fast

Load test: A load test is a performance test that refers to whether the data is running in an overloaded environment and if the program can afford it.
Focus: How much

Strength test (Stress test): Strength test is a performance test, he in the system resource is particularly low in the case of software system operation, the purpose is to find out where the system fails and how to fail the place. Including
Spike testing: Extreme load test for short periods of time
Extreme testing: Load test under excessive user
Hammer testing: Perform all the actions you can do continuously

Capacity test (Volume test): Determine the maximum number of users the system can handle simultaneously online
Focus: How much (not how fast)
Capacity testing, usually related to databases, is the difference between capacity and load: capacity is focused on large capacity without the need to show actual usage.

Among them, the capacity test, load test, strength test in English explained as:
Volume testing = Large amounts of data
Load testing = Large amount of users
Stress testing = Too Many users, Too much data, Too little time and Too little


It may be confusing to have a role performance test, a load test, and a strength test. Yes, these three concepts are relatively easy to make people confused. Load and strength tests are subsets of performance tests. Here's a running example to explain.
A performance test that represents the best situation to perform under a given benchmark. For example, in the absence of weight, how long do you need to run 100 meters (this way, no load is the benchmark).
The load test is also a performance test, but he is under a different load. For just that example, if the extension is: in 50 kg, 100 kg ... And so on, how long will it take you to run 100 meters.
Strength testing is a performance test in the case of strength. For that example, if you change to: In the case of a strong wind, you have to spend a lot of time running 100 meters without bearing or bearing.

Performance testing is the power, load test capacity, pressure test strength

Pressure test stresstest is the effect of long-time continuous operation system on the system performance under certain load conditions.

Load Test LoadTest: The time of load and system response to the system under a certain workload.

Stress testing is primarily to detect changes in the performance of a software system under one (arbitrary) condition, by altering the input of the application to impose an increasing load on the application (concurrent, cyclic, multi-user) and measuring performance changes at these different inputs, This is the usual concept: The stress test examines the maximum load that the system can withstand in the current hardware and software environment and helps to identify the bottleneck of the system. In fact, such tests can also be called load tests, but load tests often describe a particular type of stress test-increasing the number of users to stress test the application. In practice, for example, we say that starting with a relatively small load, we gradually increase the number of simulated users until the application response time expires, which means the load test.

The goal of the stress test is to test the stability of the system for a long time under a certain load, with particular attention to changes in the performance of long-running systems under large traffic conditions (for example, if the reaction slows down, if a memory leak causes the system to collapse, or if it recovers); Stress testing is a test system's limitations and It consists of two cases:
Stability pressure test: continuous operation for a long time under selected pressure values. Through this kind of pressure test, we can investigate whether the performance index is within the specified range, there is no memory leakage, there is no functional failure, etc.
Destructive stress testing: there may be some problems in the stability stress test, such as a significant reduction in system performance, but it is difficult to reveal its true cause. By means of destructive and constant pressure, the system can be quickly caused by the collapse or the problem is exposed obviously;

The goal of the load test is to test the performance of the system under a certain load (not focusing on stability, that is, not focusing on long-running, just getting the relevant performance indicators under different loads); In practice we often start with smaller loads and gradually increase the number of analog users (increasing load), Observing application response times and resources consumed under different loads until time-outs or critical resources are exhausted, which is the load test, which is the performance metric under different load conditions of the test system.

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In the simplest terms:

Load test is the test software itself can withstand the most performance test;

Stress testing is a destructive performance test;

As long as you understand the two-point difference, you understand the performance test very well.