grafana/k6 · error

the number of VUs must be more than 0

Error message

the number of VUs must be more than 0

What it means

PerVUIterationsConfig.Validate rejected a vus value <= 0. The per-VU-iterations executor runs a fixed iteration count in each of a fixed number of VUs, so at least one VU is required; the value is also segment-scaled, and a segment yielding 0 VUs fails here too.

Source

Thrown at lib/executor/per_vu_iterations.go:74

// important to note that scaling per-VU iteration executor affects only the
// number of VUs. If we also scaled the iterations, scaling would have quadratic
// effects instead of just linear.
func (pvic PerVUIterationsConfig) GetIterations() int64 {
	return pvic.Iterations.Int64
}

// GetDescription returns a human-readable description of the executor options
func (pvic PerVUIterationsConfig) GetDescription(et *lib.ExecutionTuple) string {
	return fmt.Sprintf("%d iterations for each of %d VUs%s",
		pvic.GetIterations(), pvic.GetVUs(et),
		pvic.getBaseInfo(fmt.Sprintf("maxDuration: %s", pvic.MaxDuration.Duration)))
}

// Validate makes sure all options are configured and valid
func (pvic PerVUIterationsConfig) Validate() []error {
	errors := pvic.BaseConfig.Validate()
	if pvic.VUs.Int64 <= 0 {
		errors = append(errors, fmt.Errorf("the number of VUs must be more than 0"))
	}

	if pvic.Iterations.Int64 <= 0 {
		errors = append(errors, fmt.Errorf("the number of iterations must be more than 0"))
	}

	if pvic.MaxDuration.TimeDuration() < minDuration {
		errors = append(errors, fmt.Errorf(
			"the maxDuration must be at least %s, but is %s", minDuration, pvic.MaxDuration,
		))
	}

	return errors
}

// GetExecutionRequirements returns the number of required VUs to run the
// executor for its whole duration (disregarding any startTime), including the
// maximum waiting time for any iterations to gracefully stop. This is used by

View on GitHub (pinned to 01ffac6f24)

Solutions

1. Set vus to a positive integer, e.g. vus: 10, iterations: 20
2. Ensure the execution segment is wide enough to scale to at least 1 VU

When it happens

Trigger: Thrown at lib/executor/per_vu_iterations.go:74 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@01ffac6f24 (2026-08-18). Data as JSON: /api/errors/291bb1940a643867. Report an issue: GitHub.