JMeter: Command line tests do not end

Question

When I run my Jmeter test script via command line with a thread count of up to 200 the test executes properly and at the end closes all processes and generates a proper result file. All this takes about 5 minutes.

BUT

As I increase the number of threads to 300 or more, and execute the test, it the just keeps on executing and just doesn't end. Doesn't matter if I leave it for a whole day still the test doesn't end until I manually end the test by Crtl + c or closing the command prompt itself.

Any probable reason why the tests just won't stop for a high number of threads?

Answer 1

Open you test plan in the Jmeter GUI and check the HTTP Response Timeout limit.

For this, in Jmeter,

1. Open the TEST Plan
2. Got to the HTTP Request Sampler under Threads
3. In the Timeouts section set the Response Timeout limit and Save the Test Plan.

Now try to run your test from the command line. It will stop the test after the timeout limit is reached!

Answer 2

The only way to get the reason is looking into jmeter.log file and taking a thread dump using jstack command to see where it hangs and why. You can also add the following line to user.properties file:

jmeter.save.saveservice.autoflush=true

and look into .jtl results file to see whether it is being updated. You can also open it with the listener of your choice in GUI mode to see whether response times are reasonable as it might be a problem on the application under test side.

However it might be the case of incorrect JMeter configuration, like:

1. JMeter comes with default Java Heap size of 512MB which is not enough for massive load testing
2. People often use a lot of listeners during test run, it does not make sense and slows the things down greatly
3. Inefficient usage of assertions, timers, post processors can also be the cause.

See 9 Easy Solutions for a JMeter Load Test “Out of Memory” Failure guide for comprehensive explanation and few more performance and tuning tips.