JMeter Synthesis Report generates incorrect data

Question

I'm not sure if JMeter Synthesis Report generates incorrect data or I don't understand something about JTL files. The situation is that I run distributed JMeter test in nonGUI mode with command

jmeter.bat -n -t my_test.jmx -l my_results.jtl -j info.log -r

After test finishes I generate summary report using following command (I have jmeter-plugins-synthesis-2.2.jar in my classpath)

JMeterPluginsCMD.bat --tool Reporter --generate-csv summary.csv --input-jtl my_results.jtl --plugin-type SynthesisReport

It produces nice report, but I'm not sure if I can trust it. E.g. for one test step which is Transaction controller I see max response time 21720. But when I filter all sample tags containing my step name in JTL file, I see that max value in t attribute is 11183. Do I need to add any extra values to t value to get real response time?

Answer 1

Synthesis Report should be accurate enough, you can double check it by opening your my_results.jtl file using Aggregate Report and/or Summary Report

Transaction Controller is summing up all its children execution time, so you need to sum up all Transaction Controller's children, not only take the longest sampler response time.

It might also be the case the Transaction Controller is configured to include time taken by PreProcessors, PostProcessors and Timers so if you have any of them - the difference may be due to these elements.