[connector/spanmetrics] exclude all resource attributes in spanmetrics

.chloggen/drop-resource-attribute-from-span.yaml

@@ -0,0 +1,34 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: spanmetricsconnector
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Exclude all resource attributes in spanmetrics
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [42103]
+
+# (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: |
+  This change aligns with the ServiceGraph implementation and may introduce a breaking change:
+
+  - Users utilizing Prometheus remote write will not experience a breaking change.
+  - Users using OTLP/HTTP may encounter a breaking change.
+
+  The change is currently guarded by the feature gate `connector.spanmetrics.excludeResourceMetrics` and is disabled by default. 
+  It will be enabled by default in the next release.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

connector/spanmetricsconnector/README.md

@@ -136,7 +136,8 @@ The following settings can be optionally configured:
 - `events`: Use to configure the events metric.
   - `enabled`: (default: `false`): enabling will add the events metric.
   - `dimensions`: (mandatory if `enabled`) the list of the span's event attributes to add as dimensions to the `traces.span.metrics.events` metric, which will be included _on top of_ the common and configured `dimensions` for span attributes and resource attributes.
-- `resource_metrics_key_attributes`: Filter the resource attributes used to produce the resource metrics key map hash. Use this in case changing resource attributes (e.g. process id) are breaking counter metrics.
+- `resource_metrics_key_attributes`: Filter the resource attributes used to produce the resource metrics key map hash(It's only used to build the hash key, not copy the attributes to metrics resource attributes). 
+   Use this in case changing resource attributes (e.g. process id) are breaking counter metrics.
 - `aggregation_cardinality_limit` (default: `0`): Defines the maximum number of unique combinations of dimensions that will be tracked for metrics aggregation. When the limit is reached, additional unique combinations will be dropped but registered under a new entry with `otel.metric.overflow="true"`. A value of `0` means no limit is applied.
 
 The feature gate `connector.spanmetrics.legacyMetricNames` (disabled by default) controls the connector to use legacy metric names.
@@ -289,7 +290,7 @@ More context is available in [GitHub issue #21101](https://github.com/open-telem
 
 ### About `resource_metrics_key_attributes`
 
-The `resource_metrics_key_attributes` setting controls which resource attributes are included in the metric stream identity. These attributes are used to build the key map that determines how metrics are grouped.
+The `resource_metrics_key_attributes` setting are used to build the key map that determines how metrics are grouped.
 
 If this field is left empty, the connector will use **all** available attributes to compute the resource metric hash.
 

connector/spanmetricsconnector/connector.go

@@ -278,7 +278,9 @@ func (p *connectorImp) buildMetrics() pmetric.Metrics {
 
 	p.resourceMetrics.ForEach(func(_ resourceKey, rawMetrics *resourceMetrics) {
 		rm := m.ResourceMetrics().AppendEmpty()
-		rawMetrics.attributes.CopyTo(rm.Resource().Attributes())
+		if !excludeResourceMetrics.IsEnabled() {
+			rawMetrics.attributes.CopyTo(rm.Resource().Attributes())
+		}
 
 		sm := rm.ScopeMetrics().AppendEmpty()
 		sm.Scope().SetName("spanmetricsconnector")

connector/spanmetricsconnector/connector_test.go

@@ -162,16 +162,8 @@ func verifyConsumeMetricsInput(tb testing.TB, input pmetric.Metrics, expectedTem
 	for i := 0; i < input.ResourceMetrics().Len(); i++ {
 		rm := input.ResourceMetrics().At(i)
 
-		var numDataPoints int
-		val, ok := rm.Resource().Attributes().Get(serviceNameKey)
-		require.True(tb, ok)
-		serviceName := val.AsString()
-		switch serviceName {
-		case "service-a":
-			numDataPoints = 2
-		case "service-b":
-			numDataPoints = 1
-		}
+		// validate no Resource
+		assert.Empty(tb, rm.Resource().Attributes().Len())
 
 		ilm := rm.ScopeMetrics()
 		require.Equal(tb, 1, ilm.Len())
@@ -188,6 +180,16 @@ func verifyConsumeMetricsInput(tb testing.TB, input pmetric.Metrics, expectedTem
 
 		seenMetricIDs := make(map[metricID]bool)
 		callsDps := metric.Sum().DataPoints()
+		var numDataPoints int
+		val, _ := callsDps.At(0).Attributes().Get(serviceNameKey)
+		serviceName := val.AsString()
+		switch serviceName {
+		case "service-a":
+			numDataPoints = 2
+		case "service-b":
+			numDataPoints = 1
+		}
+
 		require.Equal(tb, numDataPoints, callsDps.Len())
 		for dpi := 0; dpi < numDataPoints; dpi++ {
 			dp := callsDps.At(dpi)
@@ -765,6 +767,12 @@ func TestConsumeMetricsErrors(t *testing.T) {
 }
 
 func TestConsumeTraces(t *testing.T) {
+	// enable it
+	require.NoError(t, featuregate.GlobalRegistry().Set(excludeResourceMetrics.ID(), true))
+	defer func() {
+		require.NoError(t, featuregate.GlobalRegistry().Set(legacyMetricNamesFeatureGate.ID(), false))
+	}()
+
 	t.Parallel()
 
 	testcases := []struct {
@@ -1680,6 +1688,12 @@ func assertDataPointsHaveExactlyOneExemplarForTrace(t *testing.T, metrics pmetri
 }
 
 func TestTimestampsForUninterruptedStream(t *testing.T) {
+	// enable it
+	require.NoError(t, featuregate.GlobalRegistry().Set(excludeResourceMetrics.ID(), true))
+	defer func() {
+		require.NoError(t, featuregate.GlobalRegistry().Set(legacyMetricNamesFeatureGate.ID(), false))
+	}()
+
 	tests := []struct {
 		temporality      string
 		verifyTimestamps func(startTime1, timestamp1, startTime2, timestamp2 pcommon.Timestamp)
@@ -1757,7 +1771,7 @@ func verifyAndCollectCommonTimestamps(t *testing.T, m pmetric.Metrics) (start, t
 	for i := 0; i < m.ResourceMetrics().Len(); i++ {
 		rm := m.ResourceMetrics().At(i)
 
-		serviceName, _ := rm.Resource().Attributes().Get("service.name")
+		serviceName, _ := rm.ScopeMetrics().At(0).Metrics().At(0).Sum().DataPoints().At(0).Attributes().Get("service.name")
 		if serviceName.Str() == "unrelated-service" {
 			continue
 		}

connector/spanmetricsconnector/factory.go

@@ -26,12 +26,14 @@ const (
 	legacyMetricNamesFeatureGateID             = "connector.spanmetrics.legacyMetricNames"
 	includeCollectorInstanceIDFeatureGateID    = "connector.spanmetrics.includeCollectorInstanceID"
 	useSecondAsDefaultMetricsUnitFeatureGateID = "connector.spanmetrics.useSecondAsDefaultMetricsUnit"
+	excludeResourceMetricsFeatureGate          = "connector.spanmetrics.excludeResourceMetrics"
 )
 
 var (
 	legacyMetricNamesFeatureGate  *featuregate.Gate
 	includeCollectorInstanceID    *featuregate.Gate
 	useSecondAsDefaultMetricsUnit *featuregate.Gate
+	excludeResourceMetrics        *featuregate.Gate
 )
 
 func init() {
@@ -52,6 +54,12 @@ func init() {
 		useSecondAsDefaultMetricsUnitFeatureGateID,
 		featuregate.StageAlpha,
 		featuregate.WithRegisterDescription("When enabled, connector use second as default unit for duration metrics."),
+		featuregate.WithRegisterReferenceURL("https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/42462"),
+	)
+	excludeResourceMetrics = featuregate.GlobalRegistry().MustRegister(
+		excludeResourceMetricsFeatureGate,
+		featuregate.StageAlpha,
+		featuregate.WithRegisterDescription("When enabled, connector will exclude all resource attributes."),
 		featuregate.WithRegisterReferenceURL("https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/42103"),
 	)
 }