[prometheus components] For histograms without sums, leave the sum unset

exporter/prometheusremotewriteexporter/exporter_test.go

@@ -389,6 +389,8 @@ func Test_PushMetrics(t *testing.T) {
 
 	emptyDataPointHistogramBatch := getMetricsFromMetricList(validMetrics1[validEmptyHistogram], validMetrics2[validEmptyHistogram])
 
+	histogramNoSumBatch := getMetricsFromMetricList(validMetrics1[validHistogramNoSum], validMetrics2[validHistogramNoSum])
+
 	summaryBatch := getMetricsFromMetricList(validMetrics1[validSummary], validMetrics2[validSummary])
 
 	// len(BucketCount) > len(ExplicitBounds)
@@ -494,7 +496,14 @@ func Test_PushMetrics(t *testing.T) {
 			name:               "valid_empty_histogram_case",
 			metrics:            &emptyDataPointHistogramBatch,
 			reqTestFunc:        checkFunc,
-			expectedTimeSeries: 6,
+			expectedTimeSeries: 4,
+			httpResponseCode:   http.StatusAccepted,
+		},
+		{
+			name:               "histogram_no_sum_case",
+			metrics:            &histogramNoSumBatch,
+			reqTestFunc:        checkFunc,
+			expectedTimeSeries: 10,
 			httpResponseCode:   http.StatusAccepted,
 		},
 		{

exporter/prometheusremotewriteexporter/testutil_test.go

@@ -41,11 +41,12 @@ var (
 	label22 = "test_label22"
 	value22 = "test_value22"
 
-	intVal1   int64 = 1
-	intVal2   int64 = 2
-	floatVal1       = 1.0
-	floatVal2       = 2.0
-	floatVal3       = 3.0
+	intVal1      int64 = 1
+	intVal2      int64 = 2
+	floatValZero       = 0.0
+	floatVal1          = 1.0
+	floatVal2          = 2.0
+	floatVal3          = 3.0
 
 	lbs1    = getAttributes(label11, value11, label12, value12)
 	lbs2    = getAttributes(label21, value21, label22, value22)
@@ -62,6 +63,7 @@ var (
 	validSum            = "valid_Sum"
 	validHistogram      = "valid_Histogram"
 	validEmptyHistogram = "valid_empty_Histogram"
+	validHistogramNoSum = "valid_Histogram_No_Sum"
 	validSummary        = "valid_Summary"
 	suffixedCounter     = "valid_IntSum_total"
 
@@ -76,7 +78,8 @@ var (
 		validIntSum:         getIntSumMetric(validIntSum, lbs1, intVal1, time1),
 		suffixedCounter:     getIntSumMetric(suffixedCounter, lbs1, intVal1, time1),
 		validSum:            getSumMetric(validSum, lbs1, floatVal1, time1),
-		validHistogram:      getHistogramMetric(validHistogram, lbs1, time1, floatVal1, uint64(intVal1), bounds, buckets),
+		validHistogram:      getHistogramMetric(validHistogram, lbs1, time1, &floatVal1, uint64(intVal1), bounds, buckets),
+		validHistogramNoSum: getHistogramMetric(validHistogramNoSum, lbs1, time1, nil, uint64(intVal1), bounds, buckets),
 		validEmptyHistogram: getHistogramMetricEmptyDataPoint(validEmptyHistogram, lbs1, time1),
 		validSummary:        getSummaryMetric(validSummary, lbs1, time1, floatVal1, uint64(intVal1), quantiles),
 	}
@@ -85,11 +88,12 @@ var (
 		validDoubleGauge:    getDoubleGaugeMetric(validDoubleGauge, lbs2, floatVal2, time2),
 		validIntSum:         getIntSumMetric(validIntSum, lbs2, intVal2, time2),
 		validSum:            getSumMetric(validSum, lbs2, floatVal2, time2),
-		validHistogram:      getHistogramMetric(validHistogram, lbs2, time2, floatVal2, uint64(intVal2), bounds, buckets),
+		validHistogram:      getHistogramMetric(validHistogram, lbs2, time2, &floatVal2, uint64(intVal2), bounds, buckets),
+		validHistogramNoSum: getHistogramMetric(validHistogramNoSum, lbs2, time2, nil, uint64(intVal2), bounds, buckets),
 		validEmptyHistogram: getHistogramMetricEmptyDataPoint(validEmptyHistogram, lbs2, time2),
 		validSummary:        getSummaryMetric(validSummary, lbs2, time2, floatVal2, uint64(intVal2), quantiles),
 		validIntGaugeDirty:  getIntGaugeMetric(validIntGaugeDirty, lbs1, intVal1, time1),
-		unmatchedBoundBucketHist: getHistogramMetric(unmatchedBoundBucketHist, pcommon.NewMap(), 0, 0, 0,
+		unmatchedBoundBucketHist: getHistogramMetric(unmatchedBoundBucketHist, pcommon.NewMap(), 0, &floatValZero, 0,
 			pcommon.NewImmutableFloat64Slice([]float64{0.1, 0.2, 0.3}),
 			pcommon.NewImmutableUInt64Slice([]uint64{1, 2})),
 	}
@@ -130,8 +134,8 @@ var (
 		staleNaNDoubleGauge: getDoubleGaugeMetric(staleNaNDoubleGauge, lbs1, floatVal1, time1),
 		staleNaNIntSum:      getIntSumMetric(staleNaNIntSum, lbs1, intVal1, time1),
 		staleNaNSum:         getSumMetric(staleNaNSum, lbs1, floatVal1, time1),
-		staleNaNHistogram:   getHistogramMetric(staleNaNHistogram, lbs1, time1, floatVal2, uint64(intVal2), bounds, buckets),
-		staleNaNEmptyHistogram: getHistogramMetric(staleNaNEmptyHistogram, lbs1, time1, floatVal2, uint64(intVal2),
+		staleNaNHistogram:   getHistogramMetric(staleNaNHistogram, lbs1, time1, &floatVal2, uint64(intVal2), bounds, buckets),
+		staleNaNEmptyHistogram: getHistogramMetric(staleNaNEmptyHistogram, lbs1, time1, &floatVal2, uint64(intVal2),
 			pcommon.NewImmutableFloat64Slice([]float64{}),
 			pcommon.NewImmutableUInt64Slice([]uint64{})),
 		staleNaNSummary: getSummaryMetric(staleNaNSummary, lbs2, time2, floatVal2, uint64(intVal2), quantiles),
@@ -307,7 +311,7 @@ func getHistogramMetricEmptyDataPoint(name string, attributes pcommon.Map, ts ui
 	return metric
 }
 
-func getHistogramMetric(name string, attributes pcommon.Map, ts uint64, sum float64, count uint64, bounds pcommon.ImmutableFloat64Slice,
+func getHistogramMetric(name string, attributes pcommon.Map, ts uint64, sum *float64, count uint64, bounds pcommon.ImmutableFloat64Slice,
 	buckets pcommon.ImmutableUInt64Slice) pmetric.Metric {
 	metric := pmetric.NewMetric()
 	metric.SetName(name)
@@ -318,7 +322,10 @@ func getHistogramMetric(name string, attributes pcommon.Map, ts uint64, sum floa
 		dp.SetFlagsImmutable(pmetric.DefaultMetricDataPointFlags.WithNoRecordedValue(true))
 	}
 	dp.SetCount(count)
-	dp.SetSum(sum)
+
+	if sum != nil {
+		dp.SetSum(*sum)
+	}
 	dp.SetBucketCounts(buckets)
 	dp.SetExplicitBounds(bounds)
 	attributes.CopyTo(dp.Attributes())

pkg/translator/prometheusremotewrite/helper.go

@@ -284,17 +284,22 @@ func addSingleHistogramDataPoint(pt pmetric.HistogramDataPoint, resource pcommon
 	time := convertTimeStamp(pt.Timestamp())
 	// sum, count, and buckets of the histogram should append suffix to baseName
 	baseName := prometheustranslator.BuildPromCompliantName(metric, settings.Namespace)
-	// treat sum as a sample in an individual TimeSeries
-	sum := &prompb.Sample{
-		Value:     pt.Sum(),
-		Timestamp: time,
-	}
-	if pt.FlagsImmutable().NoRecordedValue() {
-		sum.Value = math.Float64frombits(value.StaleNaN)
-	}
 
-	sumlabels := createAttributes(resource, pt.Attributes(), settings.ExternalLabels, nameStr, baseName+sumStr)
-	addSample(tsMap, sum, sumlabels, metric.DataType().String())
+	// If the sum is unset, it indicates the _sum metric point should be
+	// omitted
+	if pt.HasSum() {
+		// treat sum as a sample in an individual TimeSeries
+		sum := &prompb.Sample{
+			Value:     pt.Sum(),
+			Timestamp: time,
+		}
+		if pt.FlagsImmutable().NoRecordedValue() {
+			sum.Value = math.Float64frombits(value.StaleNaN)
+		}
+
+		sumlabels := createAttributes(resource, pt.Attributes(), settings.ExternalLabels, nameStr, baseName+sumStr)
+		addSample(tsMap, sum, sumlabels, metric.DataType().String())
+	}
 
 	// treat count as a sample in an individual TimeSeries
 	count := &prompb.Sample{

receiver/prometheusreceiver/internal/metricfamily.go

@@ -130,7 +130,9 @@ func (mg *metricGroup) toDistributionPoint(dest pmetric.HistogramDataPointSlice)
 		point.SetFlagsImmutable(pmetric.DefaultMetricDataPointFlags.WithNoRecordedValue(true))
 	} else {
 		point.SetCount(uint64(mg.count))
-		point.SetSum(mg.sum)
+		if mg.hasSum {
+			point.SetSum(mg.sum)
+		}
 	}
 
 	point.SetExplicitBounds(pcommon.NewImmutableFloat64Slice(bounds))
@@ -171,7 +173,9 @@ func (mg *metricGroup) toSummaryPoint(dest pmetric.SummaryDataPointSlice) {
 	if pointIsStale {
 		point.SetFlagsImmutable(pmetric.DefaultMetricDataPointFlags.WithNoRecordedValue(true))
 	} else {
-		point.SetSum(mg.sum)
+		if mg.hasSum {
+			point.SetSum(mg.sum)
+		}
 		point.SetCount(uint64(mg.count))
 	}
 

receiver/prometheusreceiver/internal/metricsbuilder_test.go

@@ -915,7 +915,6 @@ func Test_OTLPMetricBuilder_histogram(t *testing.T) {
 				hist0.SetAggregationTemporality(pmetric.MetricAggregationTemporalityCumulative)
 				pt0 := hist0.DataPoints().AppendEmpty()
 				pt0.SetCount(3)
-				pt0.SetSum(0)
 				pt0.SetExplicitBounds(pcommon.NewImmutableFloat64Slice([]float64{10, 20}))
 				pt0.SetBucketCounts(pcommon.NewImmutableUInt64Slice([]uint64{1, 1, 1}))
 				pt0.SetTimestamp(startTsNanos)

unreleased/prom-unset-sum.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: prometheusreceiver/prometheusremotewriteexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Leave the sum unset in histograms without sums, and don't produce _sum metric points for histograms without sums
+
+# One or more tracking issues related to the change
+issues: [7546]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: