JMeter: the difference between using the number of threads and constant bandwidth

Question

What is the difference between Stream Numbers and Permanent Bandwidth Throughput ? Before I heard about constant bandwidth skipping , I thought that if I wanted to simulate 21 requests per minute, then the following configuration was enough:

but now that i have found this post , i'm not sure.

This is my new configuration now that I am using the Constant Bandwidth Timer :

• Does the Constant bandwidth parameter determine the override of the parameters in the stream group (number of threads, acceleration period, etc.)?
• Why even using the Constant bandwidth timer, sometimes I get several requests higher than the value indicated in the Target bandwidth (21 in the image above)
• If a indicates a value of 21 in the target bandwidth , should this constant not guarantee a maximum value of 21 requests? If so, why do I sometimes get more requests than indicated.

All your comments and ideas will be appreciated.

PS I also use a runtime controller.

Answer 1

No, it regulates the number of requests and responses received from the server per minute.

As stated in the Jmeter user manual, the throughput value should not change too often during the test - it will take some time to enter the new value. "

http://jmeter.apache.org/usermanual/component_reference.html#Constant_Throughput_Timer

The problem that you showed above will always occur in the first minute of the test run.

hope this helps.