Pass OpenTelemetry span attributes into TracesSampler callback

CHANGELOG.md

@@ -16,6 +16,8 @@
 - Fix "class ch.qos.logback.classic.spi.ThrowableProxyVO cannot be cast to class ch.qos.logback.classic.spi.ThrowableProxy" ([#4206](https://github.com/getsentry/sentry-java/pull/4206))
   - In this case we cannot report the `Throwable` to Sentry as it's not available
   - If you are using OpenTelemetry v1 `OpenTelemetryAppender`, please consider upgrading to v2
+- Pass OpenTelemetry span attributes into TracesSampler callback ([#4253](https://github.com/getsentry/sentry-java/pull/4253))
+  - `SamplingContext` now has a `getAttribute` method that grants access to OpenTelemetry span attributes via their String key (e.g. `http.request.method`)
 
 ### Features
 

sentry-opentelemetry/sentry-opentelemetry-core/src/main/java/io/sentry/opentelemetry/SentrySampler.java

@@ -23,7 +23,9 @@
 import io.sentry.TransactionContext;
 import io.sentry.clientreport.DiscardReason;
 import io.sentry.protocol.SentryId;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -64,13 +66,15 @@ public SamplingResult shouldSample(
       if (samplingDecision != null) {
         return new SentrySamplingResult(samplingDecision);
       } else {
-        return handleRootOtelSpan(traceId, parentContext);
+        return handleRootOtelSpan(traceId, parentContext, attributes);
       }
     }
   }
 
   private @NotNull SamplingResult handleRootOtelSpan(
-      final @NotNull String traceId, final @NotNull Context parentContext) {
+      final @NotNull String traceId,
+      final @NotNull Context parentContext,
+      final @NotNull Attributes attributes) {
     if (!scopes.getOptions().isTracingEnabled()) {
       return SamplingResult.create(SamplingDecision.RECORD_ONLY);
     }
@@ -96,7 +100,11 @@ public SamplingResult shouldSample(
             .getOptions()
             .getInternalTracesSampler()
             .sample(
-                new SamplingContext(transactionContext, null, propagationContext.getSampleRand()));
+                new SamplingContext(
+                    transactionContext,
+                    null,
+                    propagationContext.getSampleRand(),
+                    toMapWithStringKeys(attributes)));
 
     if (!sentryDecision.getSampled()) {
       scopes
@@ -135,6 +143,22 @@ public SamplingResult shouldSample(
     }
   }
 
+  private @NotNull Map<String, Object> toMapWithStringKeys(final @NotNull Attributes attributes) {
+    final @NotNull Map<String, Object> mapWithStringKeys = new HashMap<>(attributes.size());
+
+    if (attributes != null) {
+      attributes.forEach(
+          (key, value) -> {
+            if (key != null) {
+              final @NotNull String stringKey = key.getKey();
+              mapWithStringKeys.put(stringKey, value);
+            }
+          });
+    }
+
+    return mapWithStringKeys;
+  }
+
   @Override
   public String getDescription() {
     return "SentrySampler";

sentry/api/sentry.api

@@ -2023,7 +2023,8 @@ public final class io/sentry/RequestDetails {
 
 public final class io/sentry/SamplingContext {
 	public fun <init> (Lio/sentry/TransactionContext;Lio/sentry/CustomSamplingContext;)V
-	public fun <init> (Lio/sentry/TransactionContext;Lio/sentry/CustomSamplingContext;Ljava/lang/Double;)V
+	public fun <init> (Lio/sentry/TransactionContext;Lio/sentry/CustomSamplingContext;Ljava/lang/Double;Ljava/util/Map;)V
+	public fun getAttribute (Ljava/lang/String;)Ljava/lang/Object;
 	public fun getCustomSamplingContext ()Lio/sentry/CustomSamplingContext;
 	public fun getSampleRand ()Ljava/lang/Double;
 	public fun getTransactionContext ()Lio/sentry/TransactionContext;

sentry/src/main/java/io/sentry/SamplingContext.java

@@ -2,6 +2,8 @@
 
 import io.sentry.util.Objects;
 import io.sentry.util.SentryRandom;
+import java.util.Collections;
+import java.util.Map;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -14,6 +16,7 @@ public final class SamplingContext {
   private final @NotNull TransactionContext transactionContext;
   private final @Nullable CustomSamplingContext customSamplingContext;
   private final @NotNull Double sampleRand;
+  private final @NotNull Map<String, Object> attributes;
 
   @Deprecated
   @SuppressWarnings("InlineMeSuggester")
@@ -23,18 +26,20 @@ public final class SamplingContext {
   public SamplingContext(
       final @NotNull TransactionContext transactionContext,
       final @Nullable CustomSamplingContext customSamplingContext) {
-    this(transactionContext, customSamplingContext, SentryRandom.current().nextDouble());
+    this(transactionContext, customSamplingContext, SentryRandom.current().nextDouble(), null);
   }
 
   @ApiStatus.Internal
   public SamplingContext(
       final @NotNull TransactionContext transactionContext,
       final @Nullable CustomSamplingContext customSamplingContext,
-      final @NotNull Double sampleRand) {
+      final @NotNull Double sampleRand,
+      final @Nullable Map<String, Object> attributes) {
     this.transactionContext =
         Objects.requireNonNull(transactionContext, "transactionContexts is required");
     this.customSamplingContext = customSamplingContext;
     this.sampleRand = sampleRand;
+    this.attributes = attributes == null ? Collections.emptyMap() : attributes;
   }
 
   public @Nullable CustomSamplingContext getCustomSamplingContext() {
@@ -48,4 +53,11 @@ public SamplingContext(
   public @NotNull Double getSampleRand() {
     return sampleRand;
   }
+
+  public @Nullable Object getAttribute(final @Nullable String key) {
+    if (key == null) {
+      return null;
+    }
+    return this.attributes.get(key);
+  }
 }

sentry/src/main/java/io/sentry/Scopes.java

@@ -860,7 +860,7 @@ public void flush(long timeoutMillis) {
       final Double sampleRand = getSampleRand(transactionContext);
       final SamplingContext samplingContext =
           new SamplingContext(
-              transactionContext, transactionOptions.getCustomSamplingContext(), sampleRand);
+              transactionContext, transactionOptions.getCustomSamplingContext(), sampleRand, null);
       final @NotNull TracesSampler tracesSampler = getOptions().getInternalTracesSampler();
       @NotNull TracesSamplingDecision samplingDecision = tracesSampler.sample(samplingContext);
       transactionContext.setSamplingDecision(samplingDecision);

sentry/src/main/java/io/sentry/Sentry.java

@@ -460,7 +460,8 @@ private static void handleAppStartProfilingConfig(
     TransactionContext appStartTransactionContext = new TransactionContext("app.launch", "profile");
     appStartTransactionContext.setForNextAppStart(true);
     SamplingContext appStartSamplingContext =
-        new SamplingContext(appStartTransactionContext, null, SentryRandom.current().nextDouble());
+        new SamplingContext(
+            appStartTransactionContext, null, SentryRandom.current().nextDouble(), null);
     return options.getInternalTracesSampler().sample(appStartSamplingContext);
   }