JMeter

Thread Group

Ramp-up period (seconds):花费多少时间使得所有的线程跑起来
注意点：Ramp-up需要足够长去避免测试刚开始服务器就有一个很大的负荷
注意： When the test is started, JMeter will wait Startup Delay (seconds) before starting the Threads of the Thread Group and run for the configured Duration (seconds) time.
Note those 2 options override the Start time and End time.

start time：当测试启动时，JMeter将要等待启动时间到达，在每个测试的周期中，JMeter将check是否到达结束的时间，如果到达则停止，否则测试将继续进行直到迭代的次数达到限制

Controller
JMeter有两种Controller：Samplers和Logical Controllers，这些驱动测试的进行

Samplers 告知JMeter发送请求到服务器，如果想要发送一个HTTP请求
例如增加一个HTTP Request Sampler
也可以定制化一个请求通过增加一个或者多个配置元素给Sampler

logical controllers 让你定制化一个逻辑，使得JMeter的使用能够决定什么时候发送请求
例如：增加一个interleave logic controller 在两个HTTP 请求的sampler中进行交替

Listeners
listerner提供访问信息
Listeners provide access to the information JMeter gathers about the test cases while JMeter runs. The Graph Results listener plots the response times on a graph. The "View Results Tree" Listener shows details of sampler requests and responses, and can display basic HTML and XML representations of the response. Other listeners provide summary or aggregation information.