jmeter runs more threads than expected using jp@gc - Ultimate Thread Group

Question

I tried as a test Thread Group with the setting 1 thread, 1 ram-up, 1 loop; I verified my Aggregate Report the number of threads are as expected.

The problem comes when I run the same request using jp@gc - Ultimate Thread Group , I've tried starting from 1 thread and above but always I get more threads than I set up, see the aggregate report image.

Have tried: ver 5.2.1 and upgraded to 5.3 removing old jmeter versions removing and adding Ultimate Thread Group run through CLI and GUI

I really appreciate your help.

jp@gc - Ultimate Thread Group setting img

Aggregate report result img

Adding more details.... I am expecting reach 140 threads split in 3 different time periods (10, 30, 100), actual result is 1406 threads.

Ultimate Thread Group - 140

Actual result

Answer 1

You have 1 thread, but:

• it's being started during 1 second
• then it holds the load for 10 seconds
• and finally it has 2 seconds to shut down

I don't know how many threads do you "expect", your current setup assumes "API Performance" request for 13 seconds and the number of requests JMeter will execute will depend on your API response time. Looking into test results in the Aggregate Report it's above 2 seconds so 6 requests for 13 seconds are absolutely expected

If for some reason you're looking for having only 1 request with the current setup you can limit the number of requests JMeter will send using Throughput Controller

Check out Choosing The Right Thread Group For Your Scenario article to get more insights regarding which thread group you need to use for various workload types.

Answer 2

SAMPLES != THREADS

These refer to the number of iterations that are being executed by the bunch of threads generated by JMeter which you have defined as part of "Start Threads Count" in Ultimate Thread Group. This value is NOT THREADS

THREADS - Also considered as virtual users/active threads/active users/simulated users. These are values that you are specifying as part of "Start Threads Count" in Ultimate Thread Group. These are not measured anywhere in Aggregate Report listener but you can find it another listener named "jp@gc - Active Threads Over Time"

Simulating the same scenario as yours

My Results from Aggregate Report Listener

Your expectation is met in another listener named "jp@gc - Active Threads Over Time"

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Hope this helps!