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