Stress testing, load testing and concurrent testing What is the difference?

1, a test load (Load Test): load test is a performance test, it refers to the data in the operating environment overload, if the program can bear. Concern: How much
2, stress testing (Stress Test):
stress test (also known as strength testing) is also a performance test, it is particularly low system resources software system is running, the aim is to find where and system failures how the failure of place.
Performance testing is the driving force, load testing load, pressure strength test
stress test stress test: the impact is under a certain "load condition" for a long time continuous operation of the system to system performance.
Load testing Load test: Under certain "work load", load and systems to the system caused by the response time.
Load test is generally described a specific type of stress test - gradually increasing the number of users or user request to the system (program) is pressurized. For example, in reality there is a system to provide online inquiry service, that we start with a relatively small load, gradually increase the number of users or simulated query request,
until the system response time expires, that is to say the load test. Here pressurized type must be the type of service provided by the application, which is the workload.
The goal of load testing is to test the system performance under certain load conditions (does not care about stability, that does not care about the long run, but you can get relevant performance indicators under different load); in practice we often from relatively small load began to gradually increase the number (increase in load) simulated users,
observe application response time under different loads, the resources consumed, or until a timeout critical resource exhaustion, which is a load of said test, which is different load test system performance indicators under.
The goal of stress testing is to test the stability of the long-running system under a certain load, but this load is not necessarily caused by the application of the system itself. For example, we often use a script or a tool such as a portion of the previously eaten cpu, memory or bandwidth server, creating a certain load test environment and test the application system transaction processing capability in this environment, response time, and so on. Stress testing is particularly concerned about changes in system performance of long-running under heavy traffic situations (for example, whether slow response, will gradually cause the system to crash a memory leak, if you can recover); stress testing and fault testing system is to limit the ability to recover, it are two cases:
1. stability stress test: at a selected pressure value, a long continuous operation. Through such stress tests, we can examine the performance indicators within the specified range, with or without memory leaks, with or without functional failure;
2. destructive stress tests: there may be some problems in the stability of the stress tests, such as significantly reduce system performance, but it is difficult to expose its true cause. By means of destructive constantly pressurized, often resulting in rapid collapse of the system or let the problem clearly exposed.