What are JTL's in Jmeter? how to use them?

Question

I have read in best practices for jmeter -

Disable all JMeter graphs as they consume a lot of memory. You can view all of the real time graphs using the JTLs tab in your web interface.

How is it done? Also How can i generate graphs from JTL file. I have read that xml format for saving results to file are pretty expensive in terms of resource utilization. How can graphs be generated from logs with csv format?

Answer 1

Quote

JMeter can create text files containing the results of a test run.

These are normally called JTL files, as that is the default extension - but any extension can be used.

from https://wiki.apache.org/jmeter/JtlFiles

And you can check how to create a plan here:

https://jmeter.apache.org/usermanual/build-web-test-plan.html

Graph Results https://jmeter.apache.org/usermanual/component_reference.html#Graph_Results

Graph Results MUST NOT BE USED during load test as it consumes a lot of resources (memory and CPU). Use it only for either functional testing or during Test Plan debugging and Validation.

Just don't use it.

And here is some information as how to read the files: How to make JMeter output graphs from log-file?

Just generate you own graph.

Answer 2

You should design your load testing as follows:

1. Store only those metrics which are absolutely required (you can control what values to save using properties which names start with jmeter.save.saveservice.*
2. Run JMeter test in non-GUI mode with all listeners disabled

3. Once test is finished you can do the following:

   • Open JMeter GUI, add Listener of your choice, i.e. Aggregate Graph and using "Browse" button locate and open resulting .jtl file. JMeter will render the graph
   • Use Graphs Generator Listener

See 9 Easy Solutions for a JMeter Load Test “Out of Memory” Failure article for JMeter performance tips and tweaks.