For JMeter versions after 2.3, there are two modes of operation

additional sample is added after the nested samples

additional sample is added as a parent of the nested samples

The generated sample time includes all the times for the nested samplers, and any timers etc. Depending on the clock resolution, it may be slightly longer than the sum of the individual samplers plus timers. The clock might tick after the controller recorded the start time but before the first sample starts. Similarly at the end.

The generated sample is only regarded as successful if all its sub-samples are successful.

In parent mode, the individual samples can still be seen in the Tree View Listener, but no longer appear as separate entries in other Listeners. Also, the sub-samples do not appear in CSV log files, but they can be saved to XML files.

Control Panel Parameters Attribute Description Required Name Descriptive name for this controller that is shown in the tree, and used to name the transaction. Yes Generate Parent Sample If checked, then the sample is generated as a parent of the other samples, otherwise the sample is generated as an independent sample. Yes Include timer duration in generated sample Whether to include timer, pre- and post-processing delays in the generated sample. Default is true to be compatible with the behaviour in previous versions of JMeter. Yes