what is the difference between concurrency thread group and ultimate thread group

Question

concurrency thread group

Ultimate thread group

Answer 1

Both are pretty much similar when it comes to defining a load pattern when it comes to concurrency, however:

1. In the Ultimate Thread Group you can have > 1 row so you're more flexible when it comes to more advanced ramp-up and especially ramp-down behaviour. I.e. here is how you can add your load pattern one more time:

   

2. On the other hand Concurrency Thread Group can be connected with the Throughput Shaping Timer via Feedback Function so you will be able to control the throughput of your test execution and define it like: 100 requests per second and Concurrency Thread Group will add more threads if the current amount is not enough to reach/maintain the current throughput