Revert "[receiver/prometheus] Don't drop Histograms without buckets (#…

…23448)"

This reverts commit 5d410bb.

receiver/prometheusreceiver/internal/metricfamily.go

@@ -87,28 +87,27 @@ func (mg *metricGroup) sortPoints() {
 }
 
 func (mg *metricGroup) toDistributionPoint(dest pmetric.HistogramDataPointSlice) {
-	if !mg.hasCount {
+	if !mg.hasCount || len(mg.complexValue) == 0 {
 		return
 	}
 
 	mg.sortPoints()
 
-	bucketCount := len(mg.complexValue) + 1
-	// if the final bucket is +Inf, we ignore it
-	if bucketCount > 1 && mg.complexValue[bucketCount-2].boundary == math.Inf(1) {
-		bucketCount--
-	}
-
 	// for OTLP the bounds won't include +inf
-	bounds := make([]float64, bucketCount-1)
-	bucketCounts := make([]uint64, bucketCount)
-	var adjustedCount float64
+	bounds := make([]float64, len(mg.complexValue)-1)
+	bucketCounts := make([]uint64, len(mg.complexValue))
 
 	pointIsStale := value.IsStaleNaN(mg.sum) || value.IsStaleNaN(mg.count)
-	for i := 0; i < bucketCount-1; i++ {
-		bounds[i] = mg.complexValue[i].boundary
-		adjustedCount = mg.complexValue[i].value
 
+	for i := 0; i < len(mg.complexValue); i++ {
+		if i != len(mg.complexValue)-1 {
+			// not need to add +inf as OTLP assumes it
+			bounds[i] = mg.complexValue[i].boundary
+		} else if mg.complexValue[i].boundary != math.Inf(1) {
+			// This histogram is missing the +Inf bucket, and isn't a complete prometheus histogram.
+			return
+		}
+		adjustedCount := mg.complexValue[i].value
 		// Buckets still need to be sent to know to set them as stale,
 		// but a staleness NaN converted to uint64 would be an extremely large number.
 		// Setting to 0 instead.
@@ -120,15 +119,6 @@ func (mg *metricGroup) toDistributionPoint(dest pmetric.HistogramDataPointSlice)
 		bucketCounts[i] = uint64(adjustedCount)
 	}
 
-	// Add the final bucket based on the total count
-	adjustedCount = mg.count
-	if pointIsStale {
-		adjustedCount = 0
-	} else if bucketCount > 1 {
-		adjustedCount -= mg.complexValue[bucketCount-2].value
-	}
-	bucketCounts[bucketCount-1] = uint64(adjustedCount)
-
 	point := dest.AppendEmpty()
 
 	if pointIsStale {

receiver/prometheusreceiver/internal/metricfamily_test.go

@@ -218,28 +218,6 @@ func TestMetricGroupData_toDistributionUnitTest(t *testing.T) {
 			},
 			wantErr: true,
 		},
-		{
-			name:                "histogram without buckets",
-			metricName:          "histogram",
-			intervalStartTimeMs: 11,
-			labels:              labels.FromMap(map[string]string{"a": "A", "b": "B"}),
-			scrapes: []*scrape{
-				{at: 11, value: 66, metric: "histogram_count"},
-				{at: 11, value: 1004.78, metric: "histogram_sum"},
-			},
-			want: func() pmetric.HistogramDataPoint {
-				point := pmetric.NewHistogramDataPoint()
-				point.SetCount(66)
-				point.SetSum(1004.78)
-				point.SetTimestamp(pcommon.Timestamp(11 * time.Millisecond))      // the time in milliseconds -> nanoseconds.
-				point.SetStartTimestamp(pcommon.Timestamp(11 * time.Millisecond)) // the time in milliseconds -> nanoseconds.
-				point.BucketCounts().FromRaw([]uint64{66})
-				attributes := point.Attributes()
-				attributes.PutStr("a", "A")
-				attributes.PutStr("b", "B")
-				return point
-			},
-		},
 	}
 
 	for _, tt := range tests {

receiver/prometheusreceiver/internal/transaction_test.go

@@ -1218,20 +1218,6 @@ func TestMetricBuilderHistogram(t *testing.T) {
 			},
 			wants: func() []pmetric.Metrics {
 				md0 := pmetric.NewMetrics()
-				mL0 := md0.ResourceMetrics().AppendEmpty().ScopeMetrics().AppendEmpty().Metrics()
-				m0 := mL0.AppendEmpty()
-				m0.SetName("hist_test")
-				hist0 := m0.SetEmptyHistogram()
-				hist0.SetAggregationTemporality(pmetric.AggregationTemporalityCumulative)
-				pt0 := hist0.DataPoints().AppendEmpty()
-				pt0.SetCount(3)
-				pt0.SetSum(100)
-				pt0.BucketCounts().FromRaw([]uint64{3, 0})
-				pt0.ExplicitBounds().FromRaw([]float64{20})
-				pt0.SetTimestamp(tsNanos)
-				pt0.SetStartTimestamp(startTimestamp)
-				pt0.Attributes().PutStr("foo", "bar")
-
 				return []pmetric.Metrics{md0}
 			},
 		},
@@ -1270,27 +1256,13 @@ func TestMetricBuilderHistogram(t *testing.T) {
 			inputs: []*testScrapedPage{
 				{
 					pts: []*testDataPoint{
-						createDataPoint("hist_test_sum", 99, nil, "foo", "bar"),
-						createDataPoint("hist_test_count", 10, nil, "foo", "bar"),
+						createDataPoint("hist_test_sum", 99, nil),
+						createDataPoint("hist_test_count", 10, nil),
 					},
 				},
 			},
 			wants: func() []pmetric.Metrics {
-				md0 := pmetric.NewMetrics()
-				mL0 := md0.ResourceMetrics().AppendEmpty().ScopeMetrics().AppendEmpty().Metrics()
-				m0 := mL0.AppendEmpty()
-				m0.SetName("hist_test")
-				hist0 := m0.SetEmptyHistogram()
-				hist0.SetAggregationTemporality(pmetric.AggregationTemporalityCumulative)
-				pt0 := hist0.DataPoints().AppendEmpty()
-				pt0.SetCount(10)
-				pt0.SetSum(99)
-				pt0.BucketCounts().FromRaw([]uint64{10})
-				pt0.SetTimestamp(tsNanos)
-				pt0.SetStartTimestamp(startTimestamp)
-				pt0.Attributes().PutStr("foo", "bar")
-
-				return []pmetric.Metrics{md0}
+				return []pmetric.Metrics{pmetric.NewMetrics()}
 			},
 		},
 		{

receiver/prometheusreceiver/metrics_receiver_test.go

@@ -1087,8 +1087,8 @@ foo_total 1
 func verifyTarget3(t *testing.T, td *testData, resourceMetrics []pmetric.ResourceMetrics) {
 	verifyNumValidScrapeResults(t, td, resourceMetrics)
 	m1 := resourceMetrics[0]
-	// m1 has 4 metrics + 5 internal scraper metrics
-	assert.Equal(t, 9, metricsCount(m1))
+	// m1 has 3 metrics + 5 internal scraper metrics
+	assert.Equal(t, 8, metricsCount(m1))
 
 	wantAttributes := td.attributes
 
@@ -1116,17 +1116,7 @@ func verifyTarget3(t *testing.T, td *testData, resourceMetrics []pmetric.Resourc
 					},
 				},
 			}),
-		assertMetricPresent("corrupted_hist",
-			compareMetricType(pmetric.MetricTypeHistogram),
-			[]dataPointExpectation{
-				{
-					histogramPointComparator: []histogramPointComparator{
-						compareHistogramStartTimestamp(ts1),
-						compareHistogramTimestamp(ts1),
-						compareHistogram(10, 100, []uint64{10}),
-					},
-				},
-			}),
+		assertMetricAbsent("corrupted_hist"),
 		assertMetricPresent("rpc_duration_seconds",
 			compareMetricType(pmetric.MetricTypeSummary),
 			[]dataPointExpectation{
@@ -1151,8 +1141,8 @@ func verifyTarget3(t *testing.T, td *testData, resourceMetrics []pmetric.Resourc
 	doCompare(t, "scrape1", wantAttributes, m1, e1)
 
 	m2 := resourceMetrics[1]
-	// m2 has 4 metrics + 5 internal scraper metrics
-	assert.Equal(t, 9, metricsCount(m2))
+	// m2 has 3 metrics + 5 internal scraper metrics
+	assert.Equal(t, 8, metricsCount(m2))
 
 	metricsScrape2 := m2.ScopeMetrics().At(0).Metrics()
 	ts2 := getTS(metricsScrape2)
@@ -1178,17 +1168,7 @@ func verifyTarget3(t *testing.T, td *testData, resourceMetrics []pmetric.Resourc
 					},
 				},
 			}),
-		assertMetricPresent("corrupted_hist",
-			compareMetricType(pmetric.MetricTypeHistogram),
-			[]dataPointExpectation{
-				{
-					histogramPointComparator: []histogramPointComparator{
-						compareHistogramStartTimestamp(ts1),
-						compareHistogramTimestamp(ts2),
-						compareHistogram(15, 101, []uint64{15}),
-					},
-				},
-			}),
+		assertMetricAbsent("corrupted_hist"),
 		assertMetricPresent("rpc_duration_seconds",
 			compareMetricType(pmetric.MetricTypeSummary),
 			[]dataPointExpectation{