output a rest API specific data using jmeter

Question

During Performance testing, I want to output a rest API request and the specific data, if the response time for the request takes over a certain amount of time. For example, say you run 100 worker searches, and 10 had response times over, say, 2 seconds. I want JMeter to output a file that lists those long worker IDs.

Answer 1

You already have all the information in .jtl results file, the second column is elapsed where you have individual requests response time. So

1. Run your JMeter test in command-line non-GUI mode. Don't forget to specify desired results file location via -l command-line argument like:

   jmeter -n -t test.jmx -l results.jtl
   

2. Once your test is finished open .jtl results file (which is "normal" CSV file) using Microsoft Excel or equivalent (I'm using LibreOffice Calc). There you should be able to sort the samples results by "elapsed" time and identify the ones which took longer than 2000 milliseconds (2 seconds)

   

If you need to add an arbitrary JMeter Variable to the .jtl results file to identify the samples more precisely - take a loot at Sample Variables property

Answer 2

You can add JSR223 Timer which will be execute after Sample and check latency (response time) if more than 2 seconds (2000 milliseconds) do something as write to file, you can take any value for JMeter variables using vars.get("variableName"), example:

latency = sampler.getLatency();
if (latency >2000) {
        log.info("Save to file " + vars.get("workerId"));
}