Auto Promote requires a Canary count greater than zero

Error message

Auto Promote requires a Canary count greater than zero

What it means

Error "Auto Promote requires a Canary count greater than zero" thrown in hashicorp/nomad.

Source

Thrown at nomad/structs/structs.go:5483

	if u == nil {
		return nil
	}

	var mErr multierror.Error
	switch u.HealthCheck {
	case UpdateStrategyHealthCheck_Checks, UpdateStrategyHealthCheck_TaskStates, UpdateStrategyHealthCheck_Manual:
	default:
		_ = multierror.Append(&mErr, fmt.Errorf("Invalid health check given: %q", u.HealthCheck))
	}

	if u.MaxParallel < 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Max parallel can not be less than zero: %d < 0", u.MaxParallel))
	}
	if u.Canary < 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Canary count can not be less than zero: %d < 0", u.Canary))
	}
	if u.Canary == 0 && u.AutoPromote {
		_ = multierror.Append(&mErr, fmt.Errorf("Auto Promote requires a Canary count greater than zero"))
	}
	if u.MinHealthyTime < 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Minimum healthy time may not be less than zero: %v", u.MinHealthyTime))
	}
	if u.HealthyDeadline <= 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Healthy deadline must be greater than zero: %v", u.HealthyDeadline))
	}
	if u.ProgressDeadline < 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Progress deadline must be zero or greater: %v", u.ProgressDeadline))
	}
	if u.MinHealthyTime >= u.HealthyDeadline {
		_ = multierror.Append(&mErr, fmt.Errorf("Minimum healthy time must be less than healthy deadline: %v > %v", u.MinHealthyTime, u.HealthyDeadline))
	}
	if u.ProgressDeadline != 0 && u.HealthyDeadline >= u.ProgressDeadline {
		_ = multierror.Append(&mErr, fmt.Errorf("Healthy deadline must be less than progress deadline: %v > %v", u.HealthyDeadline, u.ProgressDeadline))
	}
	if u.Stagger <= 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Stagger must be greater than zero: %v", u.Stagger))

View on GitHub (pinned to 482b49bf1a)

When it happens

Trigger: Thrown at nomad/structs/structs.go:5483 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/330c3b68a686064b. Report an issue: GitHub.