hashicorp/nomad · error

Scaling policy invalid: %s

Error message

Scaling policy invalid: %s

What it means

The task group's scaling policy block failed its own Validate() checks; this error prefixes each individual policy error with 'Scaling policy invalid: ' when the group is validated. The actual cause is described after the prefix (e.g. missing min/max, invalid policy config).

Source

Thrown at nomad/structs/structs.go:7619

	}
	return mErr.ErrorOrNil()
}

// validateScalingPolicy ensures that the scaling policy has consistent
// min and max, not in conflict with the task group count
func (tg *TaskGroup) validateScalingPolicy(j *Job) error {
	if tg.Scaling == nil {
		return nil
	}

	var mErr multierror.Error

	err := tg.Scaling.Validate()
	if err != nil {
		// prefix scaling policy errors
		if me, ok := err.(*multierror.Error); ok {
			for _, e := range me.Errors {
				mErr.Errors = append(mErr.Errors, fmt.Errorf("Scaling policy invalid: %s", e))
			}
		}
	}

	if tg.Scaling.Max < int64(tg.Count) {
		mErr.Errors = append(mErr.Errors,
			fmt.Errorf("Scaling policy invalid: task group count must not be greater than maximum count in scaling policy"))
	}

	if int64(tg.Count) < tg.Scaling.Min && !(j.IsMultiregion() && tg.Count == 0 && j.Region == "global") {
		mErr.Errors = append(mErr.Errors,
			fmt.Errorf("Scaling policy invalid: task group count must not be less than minimum count in scaling policy"))
	}

	return mErr.ErrorOrNil()
}

// Warnings returns a list of warnings that may be from dubious settings or

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Read the text after the prefix — it names the exact policy problem
2. Ensure the scaling block defines valid min and max (max > 0, min <= max)
3. Validate the job locally with `nomad job validate` before submitting

Example fix

// before
scaling {
  enabled = true
  min     = 10
  max     = 5
}
// after
scaling {
  enabled = true
  min     = 1
  max     = 5
}

if pol := group.Scaling; pol != nil {
  if pol.Max <= 0 { return errors.New("scaling.max must be > 0") }
  if pol.Min > pol.Max { return errors.New("scaling.min must be <= scaling.max") }
}

func validScaling(p *api.ScalingPolicy) bool {
  return p == nil || (p.Max > 0 && p.Min >= 0 && p.Min <= p.Max)
}

When it happens

Trigger: Submitting a job whose task group has a `scaling` block with invalid content — e.g. min > max, missing max, invalid policy stanza — detected inside tg.Scaling.Validate().

Common situations: Hand-writing scaling blocks without min/max bounds; copy-pasted scaling policies from jobs with different types; enabling APM/target policies with wrong keys.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• Task group scaling policy validation failed: %v
• Scaling policy invalid: task group count must not be greater
• Scaling policy invalid: task group count must not be less th
• ErrConnectRequireOneNetwork
• ErrConnectInvalidNetworkMode

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/976c568ce0b6b408. Report an issue: GitHub.