VictoriaMetrics/VictoriaMetrics · error

missing `target_label` for `action=dropequal`

Error message

missing `target_label` for `action=dropequal`

What it means

Validation guard in parseRelabelConfig for action=dropequal: this action needs a destination label to compare against a source label, so target_label must be set. It fires when a dropequal relabeling rule is defined without target_label.

Source

Thrown at lib/promrelabel/config.go:340

		if len(sourceLabels) < 2 {
			return nil, fmt.Errorf("`source_labels` must contain at least two entries for `action=drop_if_equal`; got %q", sourceLabels)
		}
		if targetLabel != "" {
			return nil, fmt.Errorf("`target_label` cannot be used for `action=drop_if_equal`")
		}
		if rc.Regex != nil {
			return nil, fmt.Errorf("`regex` cannot be used for `action=drop_if_equal`")
		}
	case "keepequal":
		if targetLabel == "" {
			return nil, fmt.Errorf("missing `target_label` for `action=keepequal`")
		}
		if rc.Regex != nil {
			return nil, fmt.Errorf("`regex` cannot be used for `action=keepequal`")
		}
	case "dropequal":
		if targetLabel == "" {
			return nil, fmt.Errorf("missing `target_label` for `action=dropequal`")
		}
		if rc.Regex != nil {
			return nil, fmt.Errorf("`regex` cannot be used for `action=dropequal`")
		}
	case "keep":
		if len(sourceLabels) == 0 && rc.If == nil {
			return nil, fmt.Errorf("missing `source_labels` for `action=keep`")
		}
	case "drop":
		if len(sourceLabels) == 0 && rc.If == nil {
			return nil, fmt.Errorf("missing `source_labels` for `action=drop`")
		}
	case "hashmod":
		if len(sourceLabels) == 0 {
			return nil, fmt.Errorf("missing `source_labels` for `action=hashmod`")
		}
		if targetLabel == "" {
			return nil, fmt.Errorf("missing `target_label` for `action=hashmod`")

View on GitHub (pinned to 5079fb58f1)

Solutions

1. Add `target_label: <label_name>` to the relabeling rule
2. If comparison against the metric name was intended, use `action=drop_if_equal` instead

When it happens

Trigger: Thrown at lib/promrelabel/config.go:340 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of VictoriaMetrics/VictoriaMetrics@5079fb58f1 (2026-09-03). Data as JSON: /api/errors/fdfa3b641e380b33. Report an issue: GitHub.