Difference Between Performance Testing, Load Testing and Stress Testing – With Examples
http://www.softwaretestinghelp.com/what-is-performance-testing-load-testing-stress-testing/
Performance testing is the testing, which is performed, to ascertain how the components of a system are performing, given a particular situation. Resource usage, scalability and reliability of the product are also validated under this testing.
Load testing is meant to test the system by constantly and steadily increasing the load on the system till the time it reaches the threshold limit.
Under stress testing, various activities to overload the existing resources with excess jobs are carried out in an attempt to break the system down.
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负载测试：在一定的工作负荷下，给系统造成的负荷及系统响应的时间。
压力测试：在一定的负荷条件下，长时间连续运行系统给系统性能造成的影响。
1.性能测试（Performance Test）：通常收集所有和测试有关的所有性能，通常被不同人在不同场合下进行使用。关注点：how much和how fast
2.负载测试（Load Test）：负载测试是一种性能测试，指数据在超负荷环境中运行，程序是否能够承担。关注点：how much
3.压力测试（Stress Test）： 压力测试是一种性能测试，他在系统资源特别低的情况下软件系统运行情况，目的是找到系统在哪里失效以及如何失效的地方。包括：
- Spike testing（尖峰冲击测试）：短时间的极端负载测试
- Extreme testing（极端测试）：在过量用户下的负载测试
- Hammer testing（锤击测试）：连续执行所有能做的操作
How would you load test a webpage without using any test tools?
Load testing helps to identify a web application’s maximum operating capacity, as well as any bottlenecks that may interfere with its performance. Similarly, it can check how an application responds to variations in load.
To perform load testing, we must first identify the performance-critical scenarios and the metrics which fulfill our performance objectives. Typical criteria include:
- response time
- throughput
- resource utilization
- maximum load that the system can bear.
Then, we design tests to simulate the load, taking care to measure each of these criteria.
In the absence of formal testing tools, we can basically create our own. For example, we could simulate concurrent users by creating thousands of virtual users. We would write a multi-threaded program with thousands of threads, where each thread acts as a real-world user loading the page. For each user, we would programmatically measure response time, data I/O, etc.
We would then analyze the results
JMeter
a 100% pure Java application designed to load test functional behavior and measure performance.
Peformance testing books
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