Configure the JMeter Simple Data Writer listeners: properties, defaults, and practical usage notes for building reliable load tests.
Part of the Listeners category. Also documented in context in the full Component Reference.
TL;DR: Simple Data Writer (the underlying engine of most listeners’ “Configure” dialog) writes sample results straight to a file in CSV or XML — the lightest-weight way to persist results without a GUI listener’s memory overhead during a real load test.
This listener can record results to a file
but not to the UI. It is meant to provide an efficient means of
recording data by eliminating GUI overhead.
When running in CLI mode, the -l flag can be used to create a data file.
The fields to save are defined by JMeter properties.
See the jmeter.properties file for details.
Common gotchas
Section titled “Common gotchas”- Never run GUI listeners (View Results Tree, Graph Results) during an actual load test — they hold every sample in memory and can OOM the JVM or skew results. Use a file-writing listener like this one and analyze afterward.
- CSV output is far more compact than XML and is what the HTML Dashboard Report generator expects — stick with CSV unless something downstream specifically needs XML.
- Choose exactly which fields to save (response data, headers, etc.) — saving response bodies for every sample on a high-throughput test can produce enormous
.jtlfiles fast. - For turning the resulting file into a report, see Generating the Dashboard Report and HTML Dashboard Errors if generation fails.