Add ApplicationInsightsSampler

sdk/monitor/azure-monitor-opentelemetry-autoconfigure/src/main/java/com/azure/monitor/opentelemetry/autoconfigure/AzureMonitorAutoConfigure.java

@@ -3,6 +3,7 @@
 
 package com.azure.monitor.opentelemetry.autoconfigure;
 
+import com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorConfigurableSamplerProvider;
 import com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorLogRecordExporterProvider;
 import com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorMetricExporterProvider;
 import com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorExporterProviderKeys;
@@ -56,6 +57,7 @@ public static void customize(AutoConfigurationCustomizer autoConfigurationCustom
             props.put("otel.traces.exporter", AzureMonitorExporterProviderKeys.EXPORTER_NAME);
             props.put("otel.metrics.exporter", AzureMonitorExporterProviderKeys.EXPORTER_NAME);
             props.put("otel.logs.exporter", AzureMonitorExporterProviderKeys.EXPORTER_NAME);
+            props.put("otel.traces.sampler", AzureMonitorConfigurableSamplerProvider.SAMPLER_NAME);
             props.put(AzureMonitorExporterProviderKeys.INTERNAL_USING_AZURE_MONITOR_EXPORTER_BUILDER, "true");
             return props;
         });

sdk/monitor/azure-monitor-opentelemetry-autoconfigure/src/main/java/com/azure/monitor/opentelemetry/autoconfigure/implementation/AiSemanticAttributes.java

@@ -46,7 +46,7 @@ public final class AiSemanticAttributes {
 
     public static final AttributeKey<String> OPERATION_NAME = stringKey("applicationinsights.internal.operation_name");
 
-    public static final AttributeKey<Double> SAMPLE_RATE = doubleKey("applicationinsights.internal.sample_rate");
+    public static final AttributeKey<Double> SAMPLE_RATE = doubleKey("microsoft.sample_rate");
 
     // marks whether a request is coming from a "real" user, or a "synthetic" user (e.g. a bot or
     // health check)

sdk/monitor/azure-monitor-opentelemetry-autoconfigure/src/main/java/com/azure/monitor/opentelemetry/autoconfigure/implementation/ApplicationInsightsSampler.java

@@ -0,0 +1,79 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+// Code generated by Microsoft (R) AutoRest Code Generator.
+
+package com.azure.monitor.opentelemetry.autoconfigure.implementation;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.trace.SpanKind;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.trace.data.LinkData;
+import io.opentelemetry.sdk.trace.samplers.Sampler;
+import io.opentelemetry.sdk.trace.samplers.SamplingDecision;
+import io.opentelemetry.sdk.trace.samplers.SamplingResult;
+
+import java.util.List;
+
+public class ApplicationInsightsSampler implements Sampler {
+
+    private final double percentage;
+    private final SamplingResult recordAndSample;
+    private final String description;
+
+    public ApplicationInsightsSampler(double ratio) {
+        this.percentage = ratio * 100;
+        recordAndSample = new RecordAndSampleWithSampleRate(percentage);
+        description = "ApplicationInsightsSampler{" + ratio + "}";
+    }
+
+    @Override
+    public SamplingResult shouldSample(
+            Context parentContext,
+            String traceId,
+            String name,
+            SpanKind spanKind,
+            Attributes attributes,
+            List<LinkData> parentLinks) {
+
+        if (shouldRecordAndSample(traceId)) {
+            return recordAndSample;
+        }
+        return SamplingResult.drop();
+    }
+
+    private static class RecordAndSampleWithSampleRate implements SamplingResult {
+
+        private final Attributes attributes;
+
+        RecordAndSampleWithSampleRate(double sampleRate) {
+            attributes = Attributes.builder().put(AiSemanticAttributes.SAMPLE_RATE, sampleRate).build();
+        }
+
+        @Override
+        public SamplingDecision getDecision() {
+            return SamplingDecision.RECORD_AND_SAMPLE;
+        }
+
+        @Override
+        public Attributes getAttributes() {
+            return attributes;
+        }
+    }
+
+    private boolean shouldRecordAndSample(String traceId) {
+        if (percentage == 100) {
+            // optimization, no need to calculate score
+            return true;
+        }
+        if (percentage == 0) {
+            // optimization, no need to calculate score
+            return false;
+        }
+        return SamplingScoreGeneratorV2.getSamplingScore(traceId) < percentage;
+    }
+
+    @Override
+    public String getDescription() {
+        return description;
+    }
+}

sdk/monitor/azure-monitor-opentelemetry-autoconfigure/src/main/java/com/azure/monitor/opentelemetry/autoconfigure/implementation/AzureMonitorConfigurableSamplerProvider.java

@@ -0,0 +1,31 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+// Code generated by Microsoft (R) AutoRest Code Generator.
+
+package com.azure.monitor.opentelemetry.autoconfigure.implementation;
+
+import com.azure.monitor.opentelemetry.autoconfigure.AzureMonitorAutoConfigure;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSamplerProvider;
+import io.opentelemetry.sdk.trace.samplers.Sampler;
+
+public class AzureMonitorConfigurableSamplerProvider implements ConfigurableSamplerProvider {
+
+    public static final String SAMPLER_NAME = "azure_monitor";
+
+    @Override
+    public Sampler createSampler(ConfigProperties configProperties) {
+        if (configProperties.getBoolean(AzureMonitorExporterProviderKeys.INTERNAL_USING_AZURE_MONITOR_EXPORTER_BUILDER,
+                false)) {
+            double ratio = configProperties.getDouble("OTEL_TRACES_SAMPLER_ARG", 1);
+            return new ApplicationInsightsSampler(ratio);
+        }
+        throw new IllegalStateException(
+                getName() + " currently only supports usage via " + AzureMonitorAutoConfigure.class.getName());
+    }
+
+    @Override
+    public String getName() {
+        return SAMPLER_NAME;
+    }
+}

sdk/monitor/azure-monitor-opentelemetry-autoconfigure/src/main/java/module-info.java

@@ -28,7 +28,9 @@
     provides io.opentelemetry.sdk.autoconfigure.spi.metrics.ConfigurableMetricExporterProvider
         with com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorMetricExporterProvider;
     provides io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSpanExporterProvider
-        with com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorSpanExporterProvider;
+            with com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorSpanExporterProvider;
+    provides io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSamplerProvider
+            with com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorConfigurableSamplerProvider;
 
     exports com.azure.monitor.opentelemetry.autoconfigure;
 

sdk/monitor/azure-monitor-opentelemetry-autoconfigure/src/main/resources/META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSamplerProvider

@@ -0,0 +1 @@
+com.azure.monitor.opentelemetry.autoconfigure.implementation.AzureMonitorConfigurableSamplerProvider