Propagate sampling random value (#4153)

* wip

* wip2

* wip3

* format + api

* cleanup

* revert change to demo

* make baggage final again

* remove ObjectToString suppressing

* remove outdated comment

* remove getPropagationContext from Scopes again

* remove noop baggage and propagation context again

* fix outbox sender; test; cleanup api file

* review changes

* fix test for old span processor

* review feedback

* Format code

* changelog

---------

Co-authored-by: Sentry Github Bot <bot+github-bot@sentry.io>

Author: adinauer

CHANGELOG.md

@@ -13,6 +13,8 @@
 - Expose new `withSentryObservableEffect` method overload that accepts `SentryNavigationListener` as a parameter ([#4143](https://github.com/getsentry/sentry-java/pull/4143))
   - This allows sharing the same `SentryNavigationListener` instance across fragments and composables to preserve the trace 
 - (Internal) Add API to filter native debug images based on stacktrace addresses ([#4089](https://github.com/getsentry/sentry-java/pull/4089))
+- Propagate sampling random value ([#4153](https://github.com/getsentry/sentry-java/pull/4153))
+  - The random value used for sampling traces is now sent to Sentry and attached to the `baggage` header on outgoing requests
 
 ### Fixes
 

sentry-opentelemetry/sentry-opentelemetry-bootstrap/api/sentry-opentelemetry-bootstrap.api

@@ -20,6 +20,7 @@ public final class io/sentry/opentelemetry/InternalSemanticAttributes {
 	public static final field PROFILE_SAMPLED Lio/opentelemetry/api/common/AttributeKey;
 	public static final field PROFILE_SAMPLE_RATE Lio/opentelemetry/api/common/AttributeKey;
 	public static final field SAMPLED Lio/opentelemetry/api/common/AttributeKey;
+	public static final field SAMPLE_RAND Lio/opentelemetry/api/common/AttributeKey;
 	public static final field SAMPLE_RATE Lio/opentelemetry/api/common/AttributeKey;
 	public fun <init> ()V
 }

sentry-opentelemetry/sentry-opentelemetry-bootstrap/src/main/java/io/sentry/opentelemetry/InternalSemanticAttributes.java

@@ -8,6 +8,8 @@ public final class InternalSemanticAttributes {
   public static final AttributeKey<Boolean> SAMPLED = AttributeKey.booleanKey("sentry.sampled");
   public static final AttributeKey<Double> SAMPLE_RATE =
       AttributeKey.doubleKey("sentry.sample_rate");
+  public static final AttributeKey<Double> SAMPLE_RAND =
+      AttributeKey.doubleKey("sentry.sample_rand");
   public static final AttributeKey<Boolean> PARENT_SAMPLED =
       AttributeKey.booleanKey("sentry.parent_sampled");
   public static final AttributeKey<Boolean> PROFILE_SAMPLED =

sentry-opentelemetry/sentry-opentelemetry-bootstrap/src/main/java/io/sentry/opentelemetry/OtelSpanFactory.java

@@ -136,6 +136,8 @@ public OtelSpanFactory() {
       spanBuilder.setAttribute(InternalSemanticAttributes.SAMPLED, samplingDecision.getSampled());
       spanBuilder.setAttribute(
           InternalSemanticAttributes.SAMPLE_RATE, samplingDecision.getSampleRate());
+      spanBuilder.setAttribute(
+          InternalSemanticAttributes.SAMPLE_RAND, samplingDecision.getSampleRand());
       spanBuilder.setAttribute(
           InternalSemanticAttributes.PROFILE_SAMPLED, samplingDecision.getProfileSampled());
       spanBuilder.setAttribute(

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

@@ -14,13 +14,18 @@ public final class OtelSamplingUtil {
     final @Nullable Boolean sampled = attributes.get(InternalSemanticAttributes.SAMPLED);
     if (sampled != null) {
       final @Nullable Double sampleRate = attributes.get(InternalSemanticAttributes.SAMPLE_RATE);
+      final @Nullable Double sampleRand = attributes.get(InternalSemanticAttributes.SAMPLE_RAND);
       final @Nullable Boolean profileSampled =
           attributes.get(InternalSemanticAttributes.PROFILE_SAMPLED);
       final @Nullable Double profileSampleRate =
           attributes.get(InternalSemanticAttributes.PROFILE_SAMPLE_RATE);
 
       return new TracesSamplingDecision(
-          sampled, sampleRate, profileSampled == null ? false : profileSampled, profileSampleRate);
+          sampled,
+          sampleRate,
+          sampleRand,
+          profileSampled == null ? false : profileSampled,
+          profileSampleRate);
     } else {
       return null;
     }

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

@@ -13,12 +13,12 @@
 import io.sentry.Baggage;
 import io.sentry.BaggageHeader;
 import io.sentry.IScopes;
-import io.sentry.PropagationContext;
 import io.sentry.ScopesAdapter;
 import io.sentry.Sentry;
 import io.sentry.SentryLevel;
 import io.sentry.SentryTraceHeader;
 import io.sentry.exception.InvalidSentryTraceHeaderException;
+import io.sentry.util.TracingUtils;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -73,12 +73,17 @@ public <C> void inject(final Context context, final C carrier, final TextMapSett
       return;
     }
 
-    final @NotNull SentryTraceHeader sentryTraceHeader = sentrySpan.toSentryTrace();
-    setter.set(carrier, sentryTraceHeader.getName(), sentryTraceHeader.getValue());
-    final @Nullable BaggageHeader baggageHeader =
-        sentrySpan.toBaggageHeader(Collections.emptyList());
-    if (baggageHeader != null) {
-      setter.set(carrier, baggageHeader.getName(), baggageHeader.getValue());
+    // TODO can we use traceIfAllowed? do we have the URL here? need to access span attrs
+    final @Nullable TracingUtils.TracingHeaders tracingHeaders =
+        TracingUtils.trace(scopes, Collections.emptyList(), sentrySpan);
+
+    if (tracingHeaders != null) {
+      final @NotNull SentryTraceHeader sentryTraceHeader = tracingHeaders.getSentryTraceHeader();
+      setter.set(carrier, sentryTraceHeader.getName(), sentryTraceHeader.getValue());
+      final @Nullable BaggageHeader baggageHeader = tracingHeaders.getBaggageHeader();
+      if (baggageHeader != null) {
+        setter.set(carrier, baggageHeader.getName(), baggageHeader.getValue());
+      }
     }
   }
 
@@ -125,11 +130,6 @@ public <C> Context extract(
           .getLogger()
           .log(SentryLevel.DEBUG, "Continuing Sentry trace %s", sentryTraceHeader.getTraceId());
 
-      final @NotNull PropagationContext propagationContext =
-          PropagationContext.fromHeaders(
-              scopes.getOptions().getLogger(), sentryTraceString, baggageString);
-      scopesToUse.getIsolationScope().setPropagationContext(propagationContext);
-
       return modifiedContext;
     } catch (InvalidSentryTraceHeaderException e) {
       scopes

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

@@ -70,15 +70,10 @@ public void onStart(final @NotNull Context parentContext, final @NotNull ReadWri
         baggage = baggageFromContext;
       }
 
-      final @Nullable Boolean baggageMutable =
-          otelSpan.getAttribute(InternalSemanticAttributes.BAGGAGE_MUTABLE);
       final @Nullable String baggageString =
           otelSpan.getAttribute(InternalSemanticAttributes.BAGGAGE);
       if (baggageString != null) {
         baggage = Baggage.fromHeader(baggageString);
-        if (baggageMutable == true) {
-          baggage.freeze();
-        }
       }
 
       final @Nullable Boolean sampled = isSampled(otelSpan, samplingDecision);
@@ -87,6 +82,8 @@ public void onStart(final @NotNull Context parentContext, final @NotNull ReadWri
           new PropagationContext(
               new SentryId(traceId), sentrySpanId, sentryParentSpanId, baggage, sampled);
 
+      baggage = propagationContext.getBaggage();
+
       updatePropagationContext(scopes, propagationContext);
     }
 

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

@@ -64,7 +64,6 @@ public final class OtelSpanWrapper implements IOtelSpanWrapper {
   private final @NotNull Contexts contexts = new Contexts();
   private @Nullable String transactionName;
   private @Nullable TransactionNameSource transactionNameSource;
-  private final @Nullable Baggage baggage;
   private final @NotNull AutoClosableReentrantLock lock = new AutoClosableReentrantLock();
 
   private final @NotNull Map<String, Object> data = new ConcurrentHashMap<>();
@@ -86,17 +85,12 @@ public OtelSpanWrapper(
     this.scopes = Objects.requireNonNull(scopes, "scopes are required");
     this.span = new WeakReference<>(span);
     this.startTimestamp = startTimestamp;
-
-    if (parentSpan != null) {
-      this.baggage = parentSpan.getSpanContext().getBaggage();
-    } else if (baggage != null) {
-      this.baggage = baggage;
-    } else {
-      this.baggage = null;
-    }
-
+    final @Nullable Baggage baggageToUse =
+        baggage != null
+            ? baggage
+            : (parentSpan != null ? parentSpan.getSpanContext().getBaggage() : null);
     this.context =
-        new OtelSpanContext(span, samplingDecision, parentSpan, parentSpanId, this.baggage);
+        new OtelSpanContext(span, samplingDecision, parentSpan, parentSpanId, baggageToUse);
   }
 
   @Override
@@ -207,15 +201,16 @@ public OtelSpanWrapper(
   @Override
   public @Nullable TraceContext traceContext() {
     if (scopes.getOptions().isTraceSampling()) {
+      final @Nullable Baggage baggage = context.getBaggage();
       if (baggage != null) {
-        updateBaggageValues();
+        updateBaggageValues(baggage);
         return baggage.toTraceContext();
       }
     }
     return null;
   }
 
-  private void updateBaggageValues() {
+  private void updateBaggageValues(final @NotNull Baggage baggage) {
     try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
       if (baggage != null && baggage.isMutable()) {
         final AtomicReference<SentryId> replayIdAtomicReference = new AtomicReference<>();
@@ -238,8 +233,9 @@ private void updateBaggageValues() {
   @Override
   public @Nullable BaggageHeader toBaggageHeader(@Nullable List<String> thirdPartyBaggageHeaders) {
     if (scopes.getOptions().isTraceSampling()) {
+      final @Nullable Baggage baggage = context.getBaggage();
       if (baggage != null) {
-        updateBaggageValues();
+        updateBaggageValues(baggage);
         return BaggageHeader.fromBaggageAndOutgoingHeader(baggage, thirdPartyBaggageHeaders);
       }
     }

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

@@ -95,7 +95,8 @@ public SamplingResult shouldSample(
         scopes
             .getOptions()
             .getInternalTracesSampler()
-            .sample(new SamplingContext(transactionContext, null));
+            .sample(
+                new SamplingContext(transactionContext, null, propagationContext.getSampleRand()));
 
     if (!sentryDecision.getSampled()) {
       scopes

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

@@ -29,6 +29,7 @@ public Attributes getAttributes() {
     return Attributes.builder()
         .put(InternalSemanticAttributes.SAMPLED, sentryDecision.getSampled())
         .put(InternalSemanticAttributes.SAMPLE_RATE, sentryDecision.getSampleRate())
+        .put(InternalSemanticAttributes.SAMPLE_RAND, sentryDecision.getSampleRand())
         .put(InternalSemanticAttributes.PROFILE_SAMPLED, sentryDecision.getProfileSampled())
         .put(InternalSemanticAttributes.PROFILE_SAMPLE_RATE, sentryDecision.getProfileSampleRate())
         .build();