Counting number of requests per second generated by JMeter client

2
votes

This is how application setup goes -

  • 2 c4.8xlarge instances
  • 10 m4.4xlarge jmeter clients generating load. Each client used 70 threads

While conducting load test on a simple GET request (685 bytes size page). I came across issue of reduced throughput after some time of test run. Throughput of about 18000 requests/sec is reached with 700 threads, remains at this level for 40 minutes and then drops. Thread count remains 700 throughout the test. I have executed tests with different load patterns but results have been same.

Throughput

The application response time considerably low throughout the test -

enter image description here

According to ELB monitor, there is reduction in number of requests (and I suppose hence the lower throughput ) - enter image description here

There are no errors encountered during test run. I also set connect timeout with http request but yet no errors.

I discussed this issue with aws support at length and according to them I am not blocked by any network limit during test execution.

Given number of threads remain constant during test run, what are these threads doing? Is there a metrics I can check on to find out number of requests generated (not Hits/sec) by a JMeter client instance?

Testplan - http://justpaste.it/qyb0

1
amazon-web-servicesjmeter
Can you send share the JMX file? At least the setup. Do you have it loop forever? – Richard Friedman
I don't have loop, updated my question with link to test plan – Tarun
Did you check common system issues, e.g. jmeter's own memory size (i.e. maybe it spends more time doing GC than it should). Second common problem is when JMeter exhausts ports faster than they become available after TIME_WAIT (so reducing TIME_WAIT and increasing number of available ports would help). Second issue could also be applicable to the server side. – Kiril S.
I would also try to see if half of the jmeters produce half of the load (i.e. if with 1 jmeter the throughput remains the same, problem is likely on server side; if it is reduced by half, than on jmeter). – Kiril S.
Since I don't get java.net.BindException probable port is not an issue. – Tarun

1 Answers

0
votes

Try adding the following Test Elements: