Controlling number of Samples in bzm - Concurrency Thread Group

0
votes

I am trying to find out throughput of an endpoint using Apache Jmeter as testing tool.
I need to hit the endpoint at n threads(users) per second, and every thread should fire exactly one requests(sample).
For the above i configured bzm - Concurrency Thread Group.

Configuration One:

Target Concurrency: 100 Ramp Up Time(sec): 1 Ramp-up Steps Count: 1 Hold Target Rate Time(sec): 10

Configuration Two:

Target Concurrency: 1000 Ramp Up Time(sec): 5 Ramp-up Steps Count: 5 Hold Target Rate Time(sec): 60

What i expect is
a. Configuration One: only 1000 request must be fired in 10 sec.
b. Configuration Two: 60000 requests must be fired in 60 sec i.e 1000/sec.

1
jmeterjmeter-4.0

1 Answers

1
votes

As per your test case and test duration settings, I think, you are making confusion with the Threads and Requests.

Threads are virtual users. Threads and Requests aren't the same.

Ramp up is the time in which all the users arrive on your tested application server.

Requests are simulated by samplers but threads are the simulation of users.

Please note- The total number of requests are related to throughput, Whereas the number of active threads performing the same activity is related to concurrency.

You can achieve your requirements by using Constant Throughput Timer at your test plan level.

Constant Throughput timer allows you to maintain the throughput of your server (requests/sec). Constant Throughput Timer is only capable of pausing JMeter threads in order to slow them down to reach the target throughput. Also, it works only on a minute level so you need to properly calculate the ramp-up period and let your test run long enough.

Here are the workarounds:

  1. Calculate the number of threads you need to achieve your target throughputs. Formula is:

    RPS * max response time in second

  2. Use the Ramp-up periods for the threads to active accordingly.
  3. Make the loop count value to Forever
  4. Set the test duration accordingly.

As Constant Throughput Timer works on a minute level, to achieve X RPS you have to configure your "Target Throughput" value to X*60/min and "Calculate Throughput based on" value as "All active threads".

For example, if you need 1000 RPS, then "Target Throughput" value should be 60000/min in Constant Throughput Timer.

Check out my answers on these threads to understand your scenario more briefly.

  1. How should I calculate Ramp-up time in Jmeter

  2. Struggling to maintain Requests per Second (RPS)?

Hope this helps!