Removing fingerprint calculator from the lock on the GetSeries API (#4765)

* Removing fingerprint calculator from the lock on the GetSeries API

* Add test to prove order does not matter on QueryLimiter,AddSeries

Author: alanprot

pkg/distributor/distributor.go

@@ -1028,8 +1028,9 @@ func (d *Distributor) MetricsForLabelMatchers(ctx context.Context, from, through
 				if err := queryLimiter.AddSeries(cortexpb.FromMetricsToLabelAdapters(m)); err != nil {
 					return nil, err
 				}
+				fingerprint := m.Fingerprint()
 				mutex.Lock()
-				(*metrics)[m.Fingerprint()] = m
+				(*metrics)[fingerprint] = m
 				mutex.Unlock()
 			}
 
@@ -1060,11 +1061,13 @@ func (d *Distributor) MetricsForLabelMatchersStream(ctx context.Context, from, t
 				for _, metric := range resp.Metric {
 					m := cortexpb.FromLabelAdaptersToMetricWithCopy(metric.Labels)
 
-					if err := queryLimiter.AddSeries(cortexpb.FromMetricsToLabelAdapters(m)); err != nil {
+					if err := queryLimiter.AddSeries(metric.Labels); err != nil {
 						return nil, err
 					}
+
+					fingerprint := m.Fingerprint()
 					mutex.Lock()
-					(*metrics)[m.Fingerprint()] = m
+					(*metrics)[fingerprint] = m
 					mutex.Unlock()
 				}
 			}

pkg/util/limiter/query_limiter_test.go

@@ -45,17 +45,43 @@ func TestQueryLimiter_AddSeriers_ShouldReturnErrorOnLimitExceeded(t *testing.T)
 	)
 
 	var (
-		series1 = labels.FromMap(map[string]string{
-			labels.MetricName: metricName + "_1",
+		series1 = []cortexpb.LabelAdapter{
+			{
+				Name:  labels.MetricName,
+				Value: metricName + "_1",
+			},
+			{
+				Name:  "series1",
+				Value: "1",
+			},
+		}
+
+		series1OtherOrderLabels = []cortexpb.LabelAdapter{
+			{
+				Name:  "series1",
+				Value: "1",
+			},
+			{
+				Name:  labels.MetricName,
+				Value: metricName + "_1",
+			},
+		}
+
+		series1FromMap = labels.FromMap(map[string]string{
 			"series1":         "1",
+			labels.MetricName: metricName + "_1",
 		})
 		series2 = labels.FromMap(map[string]string{
 			labels.MetricName: metricName + "_2",
 			"series2":         "1",
 		})
 		limiter = NewQueryLimiter(1, 0, 0)
 	)
-	err := limiter.AddSeries(cortexpb.FromLabelsToLabelAdapters(series1))
+	err := limiter.AddSeries(series1)
+	require.NoError(t, err)
+	err = limiter.AddSeries(cortexpb.FromLabelsToLabelAdapters(series1FromMap))
+	require.NoError(t, err)
+	err = limiter.AddSeries(series1OtherOrderLabels)
 	require.NoError(t, err)
 	err = limiter.AddSeries(cortexpb.FromLabelsToLabelAdapters(series2))
 	require.Error(t, err)