Apache Jmeter Concurrent Users Performance Testing

Question

I want to test 400 Concurrency Users Which allow us to pass our load testing scenario as I am using below configuration setting in Apache JMeter which will through us lots of errors.

Number of Thread (Users): 400 Ramp-Up Time: 1 Loop Count: Forever Until ( Period of 1 minutes )

Answer 1

We are not telepathic enough to tell what's wrong with your setup without seeing the configuration and the nature of errors.

Several generic hints:

1. Run your test with 1-2 users/iterations to ensure it works fine and does what it is supposed to be doing. Check requests and responses details using View Results Tree listener
2. Make sure to run your test in command-line non-GUI mode and disable all the Listeners while your test is running.

3. It is better to increase and decrease the load gradually so consider using longer ramp-up time and increase test duration accordingly. I.e.

   • During the first minute virtual users arrive
   • They then hold the load for another minute
   • During the last minute virtual users leave

   This way you will be able to tell what was the load when the errors started occurring, what is the maximum number of users your application can support, where is the saturation point, does it recover when the load gets back to normal, etc. See JMeter Ramp-Up - The Ultimate Guide article for more details.

4. It might be the case you found the bottleneck, i.e. your application fails to support 400 concurrent users, now you need to find the reason which may be in:

   • incorrect middleware configuration (wrong web server, database, load balancer settings)
   • your application simply lacks resources (CPU, RAM, Network, Swap, etc.). You can check this using JMeter PerfMon Plugin
   • if infrastructure configuration is OK and there is enough headroom for the application to operate most probably the reason is in the application code, you need to inspect what it is doing using APM or Profiler tools and report the issue.