Update bucket default bounds (#3222)

* update bucket default bounds to match the specification

* add changelog entry

* test custom boundaries with valid histogram

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

CHANGELOG.md

@@ -18,6 +18,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Flush pending measurements with the `PeriodicReader` in the `go.opentelemetry.io/otel/sdk/metric` when `ForceFlush` or `Shutdown` are called. (#3220)
 - Upgrade `golang.org/x/sys/unix` from `v0.0.0-20210423185535-09eb48e85fd7` to `v0.0.0-20220919091848-fb04ddd9f9c8`.
   This addresses [GO-2022-0493](https://pkg.go.dev/vuln/GO-2022-0493). (#3235)
+- Update histogram default bounds to match the requirements of the latest specification. (#3222)
 
 ## [0.32.1] Metric SDK (Alpha) - 2022-09-22
 

exporters/prometheus/exporter_test.go

@@ -27,6 +27,8 @@ import (
 	otelmetric "go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/metric/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 func TestPrometheusExporter(t *testing.T) {
@@ -74,7 +76,7 @@ func TestPrometheusExporter(t *testing.T) {
 					attribute.Key("A").String("B"),
 					attribute.Key("C").String("D"),
 				}
-				histogram, err := meter.SyncFloat64().Histogram("baz", instrument.WithDescription("a very nice histogram"))
+				histogram, err := meter.SyncFloat64().Histogram("histogram_baz", instrument.WithDescription("a very nice histogram"))
 				require.NoError(t, err)
 				histogram.Record(ctx, 23, attrs...)
 				histogram.Record(ctx, 7, attrs...)
@@ -137,11 +139,22 @@ func TestPrometheusExporter(t *testing.T) {
 			ctx := context.Background()
 
 			exporter := New()
-			provider := metric.NewMeterProvider(metric.WithReader(exporter))
+
+			customBucketsView, err := view.New(
+				view.MatchInstrumentName("histogram_*"),
+				view.WithSetAggregation(aggregation.ExplicitBucketHistogram{
+					Boundaries: []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
+				}),
+			)
+			require.NoError(t, err)
+			defaultView, err := view.New(view.MatchInstrumentName("*"))
+			require.NoError(t, err)
+
+			provider := metric.NewMeterProvider(metric.WithReader(exporter, customBucketsView, defaultView))
 			meter := provider.Meter("testmeter")
 
 			registry := prometheus.NewRegistry()
-			err := registry.Register(exporter.Collector)
+			err = registry.Register(exporter.Collector)
 			require.NoError(t, err)
 
 			tc.recordMetrics(ctx, meter)

exporters/prometheus/testdata/histogram.txt

@@ -1,15 +1,15 @@
-# HELP baz a very nice histogram
-# TYPE baz histogram
-baz_bucket{A="B",C="D",le="0"} 0
-baz_bucket{A="B",C="D",le="5"} 0
-baz_bucket{A="B",C="D",le="10"} 1
-baz_bucket{A="B",C="D",le="25"} 1
-baz_bucket{A="B",C="D",le="50"} 0
-baz_bucket{A="B",C="D",le="75"} 0
-baz_bucket{A="B",C="D",le="100"} 0
-baz_bucket{A="B",C="D",le="250"} 2
-baz_bucket{A="B",C="D",le="500"} 0
-baz_bucket{A="B",C="D",le="1000"} 0
-baz_bucket{A="B",C="D",le="+Inf"} 4
-baz_sum{A="B",C="D"} 236
-baz_count{A="B",C="D"} 4
+# HELP histogram_baz a very nice histogram
+# TYPE histogram_baz histogram
+histogram_baz_bucket{A="B",C="D",le="0"} 0
+histogram_baz_bucket{A="B",C="D",le="5"} 0
+histogram_baz_bucket{A="B",C="D",le="10"} 1
+histogram_baz_bucket{A="B",C="D",le="25"} 1
+histogram_baz_bucket{A="B",C="D",le="50"} 0
+histogram_baz_bucket{A="B",C="D",le="75"} 0
+histogram_baz_bucket{A="B",C="D",le="100"} 0
+histogram_baz_bucket{A="B",C="D",le="250"} 2
+histogram_baz_bucket{A="B",C="D",le="500"} 0
+histogram_baz_bucket{A="B",C="D",le="1000"} 0
+histogram_baz_bucket{A="B",C="D",le="+Inf"} 4
+histogram_baz_sum{A="B",C="D"} 236
+histogram_baz_count{A="B",C="D"} 4

exporters/prometheus/testdata/sanitized_names.txt

@@ -18,7 +18,12 @@ invalid_hist_name_bucket{A="B",C="D",le="75"} 0
 invalid_hist_name_bucket{A="B",C="D",le="100"} 0
 invalid_hist_name_bucket{A="B",C="D",le="250"} 0
 invalid_hist_name_bucket{A="B",C="D",le="500"} 0
+invalid_hist_name_bucket{A="B",C="D",le="750"} 0
 invalid_hist_name_bucket{A="B",C="D",le="1000"} 0
+invalid_hist_name_bucket{A="B",C="D",le="2500"} 0
+invalid_hist_name_bucket{A="B",C="D",le="5000"} 0
+invalid_hist_name_bucket{A="B",C="D",le="7500"} 0
+invalid_hist_name_bucket{A="B",C="D",le="10000"} 0
 invalid_hist_name_bucket{A="B",C="D",le="+Inf"} 1
 invalid_hist_name_sum{A="B",C="D"} 23
 invalid_hist_name_count{A="B",C="D"} 1

sdk/metric/meter_test.go

@@ -333,8 +333,8 @@ func TestMeterCreatesInstruments(t *testing.T) {
 						{
 							Attributes:   attribute.Set{},
 							Count:        1,
-							Bounds:       []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
-							BucketCounts: []uint64{0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
+							Bounds:       []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 750, 1000, 2500, 5000, 7500, 10000},
+							BucketCounts: []uint64{0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 							Min:          &seven,
 							Max:          &seven,
 							Sum:          7.0,
@@ -397,8 +397,8 @@ func TestMeterCreatesInstruments(t *testing.T) {
 						{
 							Attributes:   attribute.Set{},
 							Count:        1,
-							Bounds:       []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
-							BucketCounts: []uint64{0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
+							Bounds:       []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 750, 1000, 2500, 5000, 7500, 10000},
+							BucketCounts: []uint64{0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 							Min:          &seven,
 							Max:          &seven,
 							Sum:          7.0,

sdk/metric/reader.go

@@ -166,7 +166,7 @@ func DefaultAggregationSelector(ik view.InstrumentKind) aggregation.Aggregation
 		return aggregation.LastValue{}
 	case view.SyncHistogram:
 		return aggregation.ExplicitBucketHistogram{
-			Boundaries: []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
+			Boundaries: []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 750, 1000, 2500, 5000, 7500, 10000},
 			NoMinMax:   false,
 		}
 	}