Signed-off-by: Ziqi Zhao <zhaoziqi9146@gmail.com>

prevent conflict metric info

exporters/prometheus/exporter.go

@@ -23,7 +23,9 @@ import (
 	"unicode"
 	"unicode/utf8"
 
+	"github.com/golang/protobuf/proto"
 	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
@@ -62,6 +64,7 @@ type collector struct {
 	disableScopeInfo     bool
 	createTargetInfoOnce sync.Once
 	scopeInfos           map[instrumentation.Scope]prometheus.Metric
+	metricFamiliesByName map[string]*dto.MetricFamily
 }
 
 // prometheus counters MUST have a _total suffix:
@@ -78,11 +81,12 @@ func New(opts ...Option) (*Exporter, error) {
 	reader := metric.NewManualReader(cfg.manualReaderOptions()...)
 
 	collector := &collector{
-		reader:            reader,
-		disableTargetInfo: cfg.disableTargetInfo,
-		withoutUnits:      cfg.withoutUnits,
-		disableScopeInfo:  cfg.disableScopeInfo,
-		scopeInfos:        make(map[instrumentation.Scope]prometheus.Metric),
+		reader:               reader,
+		disableTargetInfo:    cfg.disableTargetInfo,
+		withoutUnits:         cfg.withoutUnits,
+		disableScopeInfo:     cfg.disableScopeInfo,
+		scopeInfos:           make(map[instrumentation.Scope]prometheus.Metric),
+		metricFamiliesByName: make(map[string]*dto.MetricFamily),
 	}
 
 	if err := cfg.registerer.Register(collector); err != nil {
@@ -147,6 +151,14 @@ func (c *collector) Collect(ch chan<- prometheus.Metric) {
 		}
 
 		for _, m := range scopeMetrics.Metrics {
+			drop, m, err := c.validateMetrics(m)
+			if err != nil {
+				fmt.Printf("warning: %v\n", err)
+			}
+			if drop {
+				continue
+			}
+
 			switch v := m.Data.(type) {
 			case metricdata.Histogram:
 				addHistogramMetric(ch, v, m, keys, values, c.getName(m))
@@ -344,3 +356,116 @@ func sanitizeName(n string) string {
 
 	return b.String()
 }
+
+func (c *collector) validateMetrics(m metricdata.Metrics) (bool, metricdata.Metrics, error) {
+	// get the name of metric name
+	name := c.getName(m)
+	switch m.Data.(type) {
+	case metricdata.Sum[int64]:
+		sum := m.Data.(metricdata.Sum[int64])
+		if sum.IsMonotonic {
+			name += counterSuffix
+		}
+	case metricdata.Sum[float64]:
+		sum := m.Data.(metricdata.Sum[int64])
+		if sum.IsMonotonic {
+			name += counterSuffix
+		}
+	}
+
+	metricFamily := &dto.MetricFamily{
+		Name: proto.String(name),
+		Help: proto.String(m.Description),
+	}
+	switch m.Data.(type) {
+	case metricdata.Sum[int64]:
+		sum := m.Data.(metricdata.Sum[int64])
+		metricFamily.Type = dto.MetricType_COUNTER.Enum()
+		if !sum.IsMonotonic {
+			metricFamily.Type = dto.MetricType_GAUGE.Enum()
+		}
+	case metricdata.Sum[float64]:
+		sum := m.Data.(metricdata.Sum[float64])
+		metricFamily.Type = dto.MetricType_COUNTER.Enum()
+		if !sum.IsMonotonic {
+			metricFamily.Type = dto.MetricType_GAUGE.Enum()
+		}
+	case metricdata.Gauge[int64]:
+		metricFamily.Type = dto.MetricType_GAUGE.Enum()
+	case metricdata.Gauge[float64]:
+		metricFamily.Type = dto.MetricType_GAUGE.Enum()
+	case metricdata.Histogram:
+		metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
+	}
+
+	collision := validateCollision(metricFamily, c.metricFamiliesByName)
+	switch collision {
+	case noCollision:
+		c.metricFamiliesByName[name] = metricFamily
+		return false, m, nil
+	case typeCollision:
+		return true, m, fmt.Errorf("type collision")
+	case helpCollision:
+		emf := c.metricFamiliesByName[name]
+		m.Description = emf.GetHelp()
+		return false, m, fmt.Errorf("help collision")
+	}
+
+	return false, m, nil
+}
+
+type collisionType int
+
+const (
+	noCollision   collisionType = 0
+	typeCollision collisionType = 1
+	helpCollision collisionType = 2
+)
+
+func validateCollision(mf *dto.MetricFamily, mfs map[string]*dto.MetricFamily) collisionType {
+	newName := mf.GetName()
+	newType := mf.GetType()
+	newNameWithoutSuffix := ""
+
+	emf, exist := mfs[newName]
+	if exist {
+		if emf.GetType() != mf.GetType() {
+			return typeCollision
+		}
+
+		if emf.GetHelp() != mf.GetHelp() {
+			return helpCollision
+		}
+	}
+
+	switch {
+	case strings.HasSuffix(newName, "_count"):
+		newNameWithoutSuffix = newName[:len(newName)-6]
+	case strings.HasSuffix(newName, "_sum"):
+		newNameWithoutSuffix = newName[:len(newName)-4]
+	case strings.HasSuffix(newName, "_bucket"):
+		newNameWithoutSuffix = newName[:len(newName)-7]
+	}
+
+	if newNameWithoutSuffix != "" {
+		if emf, exist = mfs[newNameWithoutSuffix]; exist {
+			if emf.GetType() == dto.MetricType_HISTOGRAM {
+				return typeCollision
+			}
+		}
+	}
+
+	if newType == dto.MetricType_HISTOGRAM {
+		if _, exist = mfs[newName+"_count"]; exist {
+			return typeCollision
+		}
+		if _, exist = mfs[newName+"_sum"]; exist {
+			return typeCollision
+		}
+		if _, exist = mfs[newName+"_bucket"]; exist {
+			return typeCollision
+		}
+	}
+
+	return noCollision
+}

exporters/prometheus/exporter_test.go

@@ -386,3 +386,140 @@ func TestMultiScopes(t *testing.T) {
 	err = testutil.GatherAndCompare(registry, file)
 	require.NoError(t, err)
 }
+
+func TestDuplicateMetrics(t *testing.T) {
+	testCases := []struct {
+		name               string
+		customResouceAttrs []attribute.KeyValue
+		recordMetrics      func(ctx context.Context, meterA, meterB otelmetric.Meter)
+		options            []Option
+		expectedFile       string
+	}{
+		{
+			name: "no_conflict",
+			recordMetrics: func(ctx context.Context, meterA, meterB otelmetric.Meter) {
+				fooA, err := meterA.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				fooA.Add(ctx, 100, attribute.String("type", "foo"))
+
+				fooB, err := meterB.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				fooB.Add(ctx, 100, attribute.String("type", "foo"))
+			},
+			expectedFile: "testdata/no_conflict.txt",
+		},
+		{
+			name: "conflict_help",
+			recordMetrics: func(ctx context.Context, meterA, meterB otelmetric.Meter) {
+				fooA, err := meterA.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter a foo"))
+				assert.NoError(t, err)
+				fooA.Add(ctx, 100, attribute.String("type", "foo"))
+
+				fooB, err := meterB.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter b foo"))
+				assert.NoError(t, err)
+				fooB.Add(ctx, 100, attribute.String("type", "foo"))
+			},
+			expectedFile: "testdata/conflict_help.txt",
+		},
+		{
+			name: "conflict_unit",
+			recordMetrics: func(ctx context.Context, meterA, meterB otelmetric.Meter) {
+				fooA, err := meterA.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				fooA.Add(ctx, 100, attribute.String("type", "foo"))
+
+				fooB, err := meterB.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Milliseconds),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				fooB.Add(ctx, 100, attribute.String("type", "foo"))
+			},
+			options:      []Option{WithoutUnits()},
+			expectedFile: "testdata/conflict_unit.txt",
+		},
+		{
+			name: "conflict_type_counter",
+			recordMetrics: func(ctx context.Context, meterA, meterB otelmetric.Meter) {
+				counter, err := meterA.SyncInt64().Counter("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				counter.Add(ctx, 100, attribute.String("type", "foo"))
+
+				gauge, err := meterA.SyncInt64().UpDownCounter("foo_total",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				gauge.Add(ctx, 200, attribute.String("type", "foo"))
+			},
+			options:      []Option{WithoutUnits()},
+			expectedFile: "testdata/conflict_type_counter.txt",
+		},
+		{
+			name: "conflict_type_histogram",
+			recordMetrics: func(ctx context.Context, meterA, meterB otelmetric.Meter) {
+				histogram, err := meterA.SyncInt64().Histogram("foo",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				histogram.Record(ctx, 100, attribute.String("type", "foo"))
+
+				gauge, err := meterA.SyncInt64().UpDownCounter("foo_count",
+					instrument.WithUnit(unit.Bytes),
+					instrument.WithDescription("meter foo"))
+				assert.NoError(t, err)
+				gauge.Add(ctx, 200, attribute.String("type", "foo"))
+			},
+			options:      []Option{WithoutUnits()},
+			expectedFile: "testdata/conflict_type_histogram.txt",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// initialize registry exporter
+			ctx := context.Background()
+			registry := prometheus.NewRegistry()
+			exporter, err := New(append(tc.options, WithRegisterer(registry))...)
+			require.NoError(t, err)
+
+			// initialize resource
+			res, err := resource.New(ctx,
+				resource.WithAttributes(semconv.ServiceNameKey.String("prometheus_test")),
+				resource.WithAttributes(semconv.TelemetrySDKVersionKey.String("latest")),
+			)
+			require.NoError(t, err)
+			res, err = resource.Merge(resource.Default(), res)
+			require.NoError(t, err)
+
+			// initialize provider
+			provider := metric.NewMeterProvider(
+				metric.WithReader(exporter),
+				metric.WithResource(res),
+			)
+
+			// initialize two meter a, b
+			meterA := provider.Meter("ma", otelmetric.WithInstrumentationVersion("v0.1.0"))
+			meterB := provider.Meter("mb", otelmetric.WithInstrumentationVersion("v0.1.0"))
+
+			tc.recordMetrics(ctx, meterA, meterB)
+
+			file, err := os.Open(tc.expectedFile)
+			require.NoError(t, err)
+			t.Cleanup(func() { require.NoError(t, file.Close()) })
+
+			err = testutil.GatherAndCompare(registry, file)
+			require.NoError(t, err)
+		})
+	}
+}

exporters/prometheus/testdata/conflict_help.txt

@@ -0,0 +1,11 @@
+# HELP foo_bytes_total meter a foo
+# TYPE foo_bytes_total counter
+foo_bytes_total{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo"} 100
+foo_bytes_total{otel_scope_name="mb",otel_scope_version="v0.1.0",type="foo"} 100
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="ma",otel_scope_version="v0.1.0"} 1
+otel_scope_info{otel_scope_name="mb",otel_scope_version="v0.1.0"} 1
+# HELP target_info Target metadata
+# TYPE target_info gauge
+target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/conflict_type_counter.txt

@@ -0,0 +1,9 @@
+# HELP foo_total meter foo
+# TYPE foo_total counter
+foo_total{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo"} 100
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="ma",otel_scope_version="v0.1.0"} 1
+# HELP target_info Target metadata
+# TYPE target_info gauge
+target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/conflict_type_histogram.txt

@@ -0,0 +1,26 @@
+# HELP foo meter foo
+# TYPE foo histogram
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="0"} 0
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="5"} 0
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="10"} 0
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="25"} 0
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="50"} 0
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="75"} 0
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="100"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="250"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="500"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="750"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="1000"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="2500"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="5000"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="7500"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="10000"} 1
+foo_bucket{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo",le="+Inf"} 1
+foo_sum{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo"} 100
+foo_count{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo"} 1
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="ma",otel_scope_version="v0.1.0"} 1
+# HELP target_info Target metadata
+# TYPE target_info gauge
+target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/conflict_unit.txt

@@ -0,0 +1,11 @@
+# HELP foo_total meter foo
+# TYPE foo_total counter
+foo_total{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo"} 100
+foo_total{otel_scope_name="mb",otel_scope_version="v0.1.0",type="foo"} 100
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="ma",otel_scope_version="v0.1.0"} 1
+otel_scope_info{otel_scope_name="mb",otel_scope_version="v0.1.0"} 1
+# HELP target_info Target metadata
+# TYPE target_info gauge
+target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/no_conflict.txt

@@ -0,0 +1,11 @@
+# HELP foo_bytes_total meter foo
+# TYPE foo_bytes_total counter
+foo_bytes_total{otel_scope_name="ma",otel_scope_version="v0.1.0",type="foo"} 100
+foo_bytes_total{otel_scope_name="mb",otel_scope_version="v0.1.0",type="foo"} 100
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="ma",otel_scope_version="v0.1.0"} 1
+otel_scope_info{otel_scope_name="mb",otel_scope_version="v0.1.0"} 1
+# HELP target_info Target metadata
+# TYPE target_info gauge
+target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1