feat: add process.atp.enabled attribute for ATP processed metrics

.chloggen/gaurab_tagging.yaml

@@ -0,0 +1,29 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. receiver/filelog)
+component: processor/adaptivetelemetry
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add `process.atp.enabled` attribute to resources actively processed by the Adaptive Telemetry Processor"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [175]
+
+# (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: |
+  Resources that are included due to ATP filter evaluation (thresholds, anomaly detection, multi-metric, retention, include list, or zombie process detection) will now have the `process.atp.enabled=true` attribute set.
+  Resources included by default (those not targeted by ATP configuration) will not have this attribute.
+
+# 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]

processor/adaptivetelemetryprocessor/process_metrics.go

@@ -214,6 +214,13 @@ func (p *processorImp) handleIncludedResource(rm pmetric.ResourceMetrics, resour
 
 	dest := filtered.ResourceMetrics().AppendEmpty()
 	rm.CopyTo(dest)
+
+	// Add process.atp.enabled=true for resources processed by ATP
+	// Exclude stageDefaultInclusion as those weren't evaluated by ATP
+	if includeReason != stageDefaultInclusion && includeReason != "" {
+		dest.Resource().Attributes().PutBool("process.atp.enabled", true)
+	}
+
 	// Remove the internal filter stage attribute from the output, unless debugging is enabled
 	if !p.config.DebugShowAllFilterStages {
 		dest.Resource().Attributes().Remove(internalFilterStageAttributeKey)

processor/adaptivetelemetryprocessor/process_metrics_test.go

@@ -222,6 +222,37 @@ func TestProcessMetricsExtended(t *testing.T) {
 		assert.Equal(t, 0, countNonSummaryResources(result),
 			"All resources should be filtered out")
 	})
+
+	t.Run("ATP enabled attribute is set for processed resources", func(t *testing.T) {
+		// Test 1: Above threshold - should be included by ATP, not default inclusion
+		metrics := createExtendedTestMetrics(
+			map[string]string{"service.name": "atp-enabled-service"},
+			map[string]float64{"system.cpu.utilization": 90.0}, // Above threshold
+		)
+		result, err := processor.processMetrics(t.Context(), metrics)
+		assert.NoError(t, err)
+		assert.Positive(t, countNonSummaryResources(result), "Should have at least one resource")
+
+		rm := result.ResourceMetrics().At(0)
+		atpEnabled, exists := rm.Resource().Attributes().Get("process.atp.enabled")
+		assert.True(t, exists, "process.atp.enabled should be set for ATP-processed resource")
+		if exists {
+			assert.True(t, atpEnabled.Bool(), "process.atp.enabled should be true")
+		}
+
+		// Test 2: Below threshold with no matching metric - should be included by default, not ATP
+		metricsDefault := createExtendedTestMetrics(
+			map[string]string{"service.name": "default-inclusion-service"},
+			map[string]float64{"some.other.metric": 10.0}, // Not in MetricThresholds config
+		)
+		resultDefault, err := processor.processMetrics(t.Context(), metricsDefault)
+		assert.NoError(t, err)
+		assert.Positive(t, countNonSummaryResources(resultDefault), "Should have at least one resource")
+
+		rmDefault := resultDefault.ResourceMetrics().At(0)
+		_, existsDefault := rmDefault.Resource().Attributes().Get("process.atp.enabled")
+		assert.False(t, existsDefault, "process.atp.enabled should NOT be set for default-included resource")
+	})
 }
 
 // Helper function to count metrics in a batch, excluding summary metrics