[Jmeter] Concurrency Thread Group

Concurrency Thread Group : https://jmeter-plugins.org/wiki/ConcurrencyThreadGroup/

参数介绍：

Target Concurrency: Number of Threads 目标用户并发数

Ramp Up Time: for the whole test  增加并发用户数的总时间

Ramp-Up Steps Count  增加并发用户数的次数

Hold Target Rate Time:  并发用户数达到目标之后持续的测试时间

Time Unit : minutes or seconds

Thread Iterations Limit: Numbers of Loops

Log Threads Status into File: saving thread start and thread stop events as a log file

Let’s look at the following scenario:

- 100 threads

- 30 minutes Ramp Up Time

- 10 Ramp-Up Steps

- 30 minutes holding the target rate

This means that:

- 每3分钟（30 minutes Ramp Up Time/10 Ramp-Up Steps）加10个用户（100 threads/10 Ramp-Up Steps），直到用户数达到100（100 threads）

- Every 3 minutes 10 users will be added until we reach 100 users. ( 30 minutes divided by 10 steps equals 3 minutes per step. 100 users divided by 10 steps equals 10 users per step. Totaling - 10 users every 3 minutes).

- 当用户数达到100，这100个用户将继续向服务器发送请求，持续30分钟（30 minutes holding the target rate）

- After reaching 100 threads all of them will continue running and hitting the server together for 30 minutes