Identify global Tracers and Meters with their schema URLs

CHANGELOG.md

@@ -11,6 +11,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Fixed
 
 - Log a warning to the OpenTelemetry internal logger when a `Record` in `go.opentelemetry.io/otel/sdk/log` drops an attribute due to a limit being reached. (#5376)
+- Identify the `Tracer` returned from the global `TracerProvider` in `go.opentelemetry.io/otel/global` with its schema URL. (#5426)
+- Identify the `Meter` returned from the global `MeterProvider` in `go.opentelemetry.io/otel/global` with its schema URL. (#5426)
 
 ## [1.27.0/0.49.0/0.3.0] 2024-05-21
 

internal/global/meter.go

@@ -65,6 +65,7 @@ func (p *meterProvider) Meter(name string, opts ...metric.MeterOption) metric.Me
 	key := il{
 		name:    name,
 		version: c.InstrumentationVersion(),
+		schema:  c.SchemaURL(),
 	}
 
 	if p.meters == nil {

internal/global/meter_test.go

@@ -375,3 +375,39 @@ func TestRegistrationDelegation(t *testing.T) {
 		assert.NoError(t, reg1.Unregister(), "duplicate unregister calls")
 	})
 }
+
+func TestMeterIdentity(t *testing.T) {
+	type id struct{ name, ver, url string }
+
+	ids := []id{
+		{"name-a", "version-a", "url-a"},
+		{"name-a", "version-a", "url-b"},
+		{"name-a", "version-b", "url-a"},
+		{"name-a", "version-b", "url-b"},
+		{"name-b", "version-a", "url-a"},
+		{"name-b", "version-a", "url-b"},
+		{"name-b", "version-b", "url-a"},
+		{"name-b", "version-b", "url-b"},
+	}
+
+	provider := &meterProvider{}
+	newMeter := func(i id) metric.Meter {
+		return provider.Meter(
+			i.name,
+			metric.WithInstrumentationVersion(i.ver),
+			metric.WithSchemaURL(i.url),
+		)
+	}
+
+	for i, id0 := range ids {
+		for j, id1 := range ids {
+			l0, l1 := newMeter(id0), newMeter(id1)
+
+			if i == j {
+				assert.Samef(t, l0, l1, "Meter(%v) != Meter(%v)", id0, id1)
+			} else {
+				assert.NotSamef(t, l0, l1, "Meter(%v) == Meter(%v)", id0, id1)
+			}
+		}
+	}
+}

internal/global/trace.go

@@ -86,6 +86,7 @@ func (p *tracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.T
 	key := il{
 		name:    name,
 		version: c.InstrumentationVersion(),
+		schema:  c.SchemaURL(),
 	}
 
 	if p.tracers == nil {
@@ -101,10 +102,7 @@ func (p *tracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.T
 	return t
 }
 
-type il struct {
-	name    string
-	version string
-}
+type il struct{ name, version, schema string }
 
 // tracer is a placeholder for a trace.Tracer.
 //

internal/global/trace_test.go

@@ -235,3 +235,39 @@ func TestSpanContextPropagatedWithNonRecordingSpan(t *testing.T) {
 	assert.Equal(t, sc, span.SpanContext())
 	assert.False(t, span.IsRecording())
 }
+
+func TestTracerIdentity(t *testing.T) {
+	type id struct{ name, ver, url string }
+
+	ids := []id{
+		{"name-a", "version-a", "url-a"},
+		{"name-a", "version-a", "url-b"},
+		{"name-a", "version-b", "url-a"},
+		{"name-a", "version-b", "url-b"},
+		{"name-b", "version-a", "url-a"},
+		{"name-b", "version-a", "url-b"},
+		{"name-b", "version-b", "url-a"},
+		{"name-b", "version-b", "url-b"},
+	}
+
+	provider := &tracerProvider{}
+	newTracer := func(i id) trace.Tracer {
+		return provider.Tracer(
+			i.name,
+			trace.WithInstrumentationVersion(i.ver),
+			trace.WithSchemaURL(i.url),
+		)
+	}
+
+	for i, id0 := range ids {
+		for j, id1 := range ids {
+			l0, l1 := newTracer(id0), newTracer(id1)
+
+			if i == j {
+				assert.Samef(t, l0, l1, "Tracer(%v) != Tracer(%v)", id0, id1)
+			} else {
+				assert.NotSamef(t, l0, l1, "Tracer(%v) == Tracer(%v)", id0, id1)
+			}
+		}
+	}
+}