What causes "maximum count must not be less than minimum count" in hashicorp/nomad?

Raise `max` to be greater than or equal to `min`.

maximum count must not be less than minimum count

Error message

maximum count must not be less than minimum count

What it means

ScalingPolicy.Validate() requires max >= min. When the policy's Max is non-negative but strictly less than Min, this error is appended to the multierror. The count range would otherwise be contradictory (the scaler could never move within it).

Source

Thrown at nomad/structs/structs.go:6447

		return nil
	}

	var mErr multierror.Error

	// Check policy type and target
	if p.Type == "" {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("missing scaling policy type"))
	} else {
		mErr.Errors = append(mErr.Errors, p.validateType().Errors...)
	}

	// Check Min and Max
	if p.Max < 0 {
		mErr.Errors = append(mErr.Errors,
			fmt.Errorf("maximum count must be specified and non-negative"))
	} else if p.Max < p.Min {
		mErr.Errors = append(mErr.Errors,
			fmt.Errorf("maximum count must not be less than minimum count"))
	}

	if p.Min < 0 {
		mErr.Errors = append(mErr.Errors,
			fmt.Errorf("minimum count must be specified and non-negative"))
	}

	return mErr.ErrorOrNil()
}

func (p *ScalingPolicy) validateTargetHorizontal() (mErr multierror.Error) {
	if len(p.Target) == 0 {
		// This is probably not a Nomad horizontal policy
		return
	}

	// Nomad horizontal policies should have Namespace, Job and TaskGroup
	if p.Target[ScalingTargetNamespace] == "" {

View on GitHub (pinned to 482b49bf1a)

Solutions

Raise `max` to be greater than or equal to `min`.
Lower `min` if it was set too high relative to the intended max.
Run `nomad job validate` after the fix to confirm no other policy errors remain.

Example fix

// before
scaling {
  min = 5
  max = 2
}
// after
scaling {
  min = 2
  max = 5
}

Defensive patterns

Strategy: validation

Validate before calling

if policy.Min >= 0 && policy.Max >= 0 && policy.Max < policy.Min {
	return fmt.Errorf("max (%d) must be >= min (%d)", policy.Max, policy.Min)
}

Prevention

Enforce min <= max in any tooling that writes scaling blocks.
When lowering max via the autoscaler, first lower or check min.
Keep min/max as paired (min,max) variables to avoid swapped values.

When it happens

Trigger: Submitting a scaling block like `min = 5, max = 2`, or swapping the values when copying an example, or updating max downward below the current min via the scaling policy API.

Common situations: Copy-paste mistakes in HCL; autoscaler configs edited manually where min was raised later and max was not; templated jobs with reversed interpolation of min/max variables.

Related errors

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/3d414d2f3f3693f2. Report an issue: GitHub.