extend logging for detected duplicated labels

nerdswords · Sep 26, 2024 · ec1739a · ec1739a
1 parent 1d2077a
commit ec1739a
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 8 deletions.
diff --git a/pkg/promutil/migrate.go b/pkg/promutil/migrate.go
@@ -301,8 +301,8 @@ func EnsureLabelConsistencyAndRemoveDuplicates(metrics []*PrometheusMetric, obse
 		}
 
 		if len(observedLabels) != metric.LabelsLen() {
-			logger.Warn("metric has duplicate labels", "metric_name", metric.Name(), "observed_labels", len(observedLabels), "labels_len", metric.LabelsLen())
-			metric.RemoveDuplicateLabels()
+			duplicates := metric.RemoveDuplicateLabels()
+			logger.Warn("metric has duplicate labels", "metric_name", metric.Name(), "observed_labels", len(observedLabels), "labels_len", metric.LabelsLen(), "duplicated_labels", duplicates)
 		}
 
 		metricKey := metric.Name() + "-" + strconv.FormatUint(metric.LabelsSignature(), 10)

diff --git a/pkg/promutil/prometheus.go b/pkg/promutil/prometheus.go
@@ -203,19 +203,23 @@ func (p *PrometheusMetric) AddIfMissingLabelPair(key, val string) {
 	}
 }
 
-func (p *PrometheusMetric) RemoveDuplicateLabels() {
+func (p *PrometheusMetric) RemoveDuplicateLabels() []string {
 	seen := map[string]struct{}{}
+	duplicates := []string{}
 	idx := 0
 	for i, key := range p.labels.keys {
 		if _, ok := seen[key]; !ok {
 			seen[key] = struct{}{}
 			p.labels.keys[idx] = key
 			p.labels.vals[idx] = p.labels.vals[i]
 			idx++
+		} else {
+			duplicates = append(duplicates, key)
 		}
 	}
 	p.labels.keys = p.labels.keys[:idx]
 	p.labels.vals = p.labels.vals[:idx]
+	return duplicates
 }
 
 type PrometheusCollector struct {

diff --git a/pkg/promutil/prometheus_test.go b/pkg/promutil/prometheus_test.go
@@ -153,12 +153,13 @@ func TestPrometheusMetric(t *testing.T) {
 	})
 
 	t.Run("RemoveDuplicateLabels", func(t *testing.T) {
-		metric := NewPrometheusMetric("metric", []string{"key1", "key1"}, []string{"value1", "value2"}, 1.0)
-		require.Equal(t, 2, metric.LabelsLen())
-		metric.RemoveDuplicateLabels()
+		metric := NewPrometheusMetric("metric", []string{"key1", "key2", "key1", "key3"}, []string{"value-key1", "value-key2", "value-dup-key1", "value-key3"}, 1.0)
+		require.Equal(t, 4, metric.LabelsLen())
+		duplicates := metric.RemoveDuplicateLabels()
 		keys, vals := metric.Labels()
-		require.Equal(t, []string{"key1"}, keys)
-		require.Equal(t, []string{"value1"}, vals)
+		require.Equal(t, []string{"key1", "key2", "key3"}, keys)
+		require.Equal(t, []string{"value-key1", "value-key2", "value-key3"}, vals)
+		require.Equal(t, []string{"key1"}, duplicates)
 	})
 }