Concepts

These topics explain the essential concepts of how scenarios and their executors work.

Different scenario configurations can affect many different aspects of your system, including the generated load, utilized resources, and emitted metrics. If you know a bit about how scenarios work, you’ll design better tests and interpret test results with more understanding.

On this page	Read about
Open and closed models	Different ways k6 can schedule VUs, their affects on test results, and how k6 implements the open model in its arrival-rate executors
Graceful Stop	A configurable period for iterations to finish or ramp down after the test reaches its scheduled duration
Arrival-rate VU allocation	How k6 allocates VUs in arrival-rate executors
Dropped iterations	Possible reasons k6 might drop a scheduled iteration