feat: Add Sampling Decision to Trace Envelope Header

CHANGELOG.md

@@ -9,7 +9,8 @@
 
 ### Features
 
-- Rename "http.method" to "http.request.method" for network Spans #3268
+- Rename "http.method" to "http.request.method" for network Spans (#3268)
+- Add Sampling Decision to Trace Envelope Header (#3286)
 
 ## 8.11.0
 

Samples/iOS-Swift/iOS-Swift.xcodeproj/project.pbxproj

@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 52;
+	objectVersion = 54;
 	objects = {
 
 /* Begin PBXBuildFile section */

Sources/Sentry/Public/SentryDefines.h

@@ -118,6 +118,9 @@ static DEPRECATED_MSG_ATTRIBUTE(
 
 static NSUInteger const defaultMaxBreadcrumbs = 100;
 
+static NSString *_Nonnull const kSentryTrueString = @"true";
+static NSString *_Nonnull const kSentryFalseString = @"false";
+
 /**
  * Transaction name source.
  */

Sources/Sentry/SentryBaggage.m

@@ -17,6 +17,7 @@ - (instancetype)initWithTraceId:(SentryId *)traceId
                     transaction:(nullable NSString *)transaction
                     userSegment:(nullable NSString *)userSegment
                      sampleRate:(nullable NSString *)sampleRate
+                        sampled:(nullable NSString *)sampled
 {
 
     if (self = [super init]) {
@@ -27,6 +28,7 @@ - (instancetype)initWithTraceId:(SentryId *)traceId
         _transaction = transaction;
         _userSegment = userSegment;
         _sampleRate = sampleRate;
+        _sampled = sampled;
     }
 
     return self;
@@ -65,6 +67,10 @@ - (NSString *)toHTTPHeaderWithOriginalBaggage:(NSDictionary *_Nullable)originalB
         [information setValue:_sampleRate forKey:@"sentry-sample_rate"];
     }
 
+    if (_sampled != nil) {
+        [information setValue:_sampled forKey:@"sentry-sampled"];
+    }
+
     return [SentrySerialization baggageEncodedDictionary:information];
 }
 

Sources/Sentry/SentryPropagationContext.m

@@ -38,7 +38,8 @@ - (SentryTraceContext *)traceContext
                                            environment:options.environment
                                            transaction:nil
                                            userSegment:scope.userObject.segment
-                                            sampleRate:nil];
+                                            sampleRate:nil
+                                               sampled:nil];
 }
 
 - (NSDictionary<NSString *, NSString *> *)traceContextForEvent

Sources/Sentry/SentryTraceContext.m

@@ -1,9 +1,11 @@
 #import "SentryTraceContext.h"
 #import "SentryBaggage.h"
+#import "SentryDefines.h"
 #import "SentryDsn.h"
 #import "SentryId.h"
 #import "SentryLog.h"
 #import "SentryOptions+Private.h"
+#import "SentrySampleDecision.h"
 #import "SentryScope+Private.h"
 #import "SentrySerialization.h"
 #import "SentryTracer.h"
@@ -21,6 +23,7 @@ - (instancetype)initWithTraceId:(SentryId *)traceId
                     transaction:(nullable NSString *)transaction
                     userSegment:(nullable NSString *)userSegment
                      sampleRate:(nullable NSString *)sampleRate
+                        sampled:(nullable NSString *)sampled
 {
     if (self = [super init]) {
         _traceId = traceId;
@@ -30,6 +33,7 @@ - (instancetype)initWithTraceId:(SentryId *)traceId
         _transaction = transaction;
         _userSegment = userSegment;
         _sampleRate = sampleRate;
+        _sampled = sampled;
     }
     return self;
 }
@@ -63,13 +67,20 @@ - (nullable instancetype)initWithTracer:(SentryTracer *)tracer
             [NSString stringWithFormat:@"%@", [(SentryTransactionContext *)tracer sampleRate]];
     }
 
+    NSString *sampled = nil;
+    if (tracer.sampled != kSentrySampleDecisionUndecided) {
+        sampled
+            = tracer.sampled == kSentrySampleDecisionYes ? kSentryTrueString : kSentryFalseString;
+    }
+
     return [self initWithTraceId:tracer.traceId
                        publicKey:options.parsedDsn.url.user
                      releaseName:options.releaseName
                      environment:options.environment
                      transaction:tracer.transactionContext.name
                      userSegment:userSegment
-                      sampleRate:sampleRate];
+                      sampleRate:sampleRate
+                         sampled:sampled];
 }
 
 - (nullable instancetype)initWithDict:(NSDictionary<NSString *, id> *)dictionary
@@ -94,7 +105,8 @@ - (nullable instancetype)initWithDict:(NSDictionary<NSString *, id> *)dictionary
                      environment:dictionary[@"environment"]
                      transaction:dictionary[@"transaction"]
                      userSegment:userSegment
-                      sampleRate:dictionary[@"sample_rate"]];
+                      sampleRate:dictionary[@"sample_rate"]
+                         sampled:dictionary[@"sampled"]];
 }
 
 - (SentryBaggage *)toBaggage
@@ -105,7 +117,8 @@ - (SentryBaggage *)toBaggage
                                                        environment:_environment
                                                        transaction:_transaction
                                                        userSegment:_userSegment
-                                                        sampleRate:_sampleRate];
+                                                        sampleRate:_sampleRate
+                                                           sampled:_sampled];
     return result;
 }
 
@@ -134,6 +147,10 @@ - (SentryBaggage *)toBaggage
         [result setValue:_sampleRate forKey:@"sample_rate"];
     }
 
+    if (_sampled != nil) {
+        [result setValue:_sampleRate forKey:@"sampled"];
+    }
+
     return result;
 }
 

Sources/Sentry/include/SentryBaggage.h

@@ -49,13 +49,19 @@ static NSString *const SENTRY_BAGGAGE_HEADER = @"baggage";
  */
 @property (nullable, nonatomic, readonly) NSString *sampleRate;
 
+/**
+ * Value indicating whether the trace was sampled.
+ */
+@property (nullable, nonatomic, strong) NSString *sampled;
+
 - (instancetype)initWithTraceId:(SentryId *)traceId
                       publicKey:(NSString *)publicKey
                     releaseName:(nullable NSString *)releaseName
                     environment:(nullable NSString *)environment
                     transaction:(nullable NSString *)transaction
                     userSegment:(nullable NSString *)userSegment
-                     sampleRate:(nullable NSString *)sampleRate;
+                     sampleRate:(nullable NSString *)sampleRate
+                        sampled:(nullable NSString *)sampled;
 
 - (NSString *)toHTTPHeader;
 - (NSString *)toHTTPHeaderWithOriginalBaggage:(NSDictionary *_Nullable)originalBaggage;

Sources/Sentry/include/SentryTraceContext.h

@@ -50,7 +50,12 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  * Sample rate used for this trace.
  */
-@property (nullable, nonatomic, strong) NSString *sampleRate;
+@property (nullable, nonatomic, readonly) NSString *sampleRate;
+
+/**
+ * Value indicating whether the trace was sampled.
+ */
+@property (nullable, nonatomic, readonly) NSString *sampled;
 
 /**
  * Initializes a SentryTraceContext with given properties.
@@ -61,7 +66,8 @@ NS_ASSUME_NONNULL_BEGIN
                     environment:(nullable NSString *)environment
                     transaction:(nullable NSString *)transaction
                     userSegment:(nullable NSString *)userSegment
-                     sampleRate:(nullable NSString *)sampleRate;
+                     sampleRate:(nullable NSString *)sampleRate
+                        sampled:(nullable NSString *)sampled;
 
 /**
  * Initializes a SentryTraceContext with data from scope and options.

Tests/SentryTests/Helper/SentrySerializationTests.swift

@@ -4,7 +4,7 @@ class SentrySerializationTests: XCTestCase {
 
     private class Fixture {
         static var invalidData = "hi".data(using: .utf8)!
-        static var traceContext = SentryTraceContext(trace: SentryId(), publicKey: "PUBLIC_KEY", releaseName: "RELEASE_NAME", environment: "TEST", transaction: "transaction", userSegment: "some segment", sampleRate: "0.25")
+        static var traceContext = SentryTraceContext(trace: SentryId(), publicKey: "PUBLIC_KEY", releaseName: "RELEASE_NAME", environment: "TEST", transaction: "transaction", userSegment: "some segment", sampleRate: "0.25", sampled: "true")
     }
 
     func testSerializationFailsWithInvalidJSONObject() {
@@ -123,7 +123,7 @@ class SentrySerializationTests: XCTestCase {
     }
 
     func testSentryEnvelopeSerializer_TraceStateWithoutUser() {
-        let trace = SentryTraceContext(trace: SentryId(), publicKey: "PUBLIC_KEY", releaseName: "RELEASE_NAME", environment: "TEST", transaction: "transaction", userSegment: nil, sampleRate: nil)
+        let trace = SentryTraceContext(trace: SentryId(), publicKey: "PUBLIC_KEY", releaseName: "RELEASE_NAME", environment: "TEST", transaction: "transaction", userSegment: nil, sampleRate: nil, sampled: nil)
 
         let envelopeHeader = SentryEnvelopeHeader(id: nil, traceContext: trace)
         let envelope = SentryEnvelope(header: envelopeHeader, singleItem: createItemWithEmptyAttachment())

Tests/SentryTests/Protocol/SentryEnvelopeTests.swift

@@ -158,7 +158,7 @@ class SentryEnvelopeTests: XCTestCase {
 
     func testInitSentryEnvelopeHeader_SetIdAndTraceState() {
         let eventId = SentryId()
-        let traceContext = SentryTraceContext(trace: SentryId(), publicKey: "publicKey", releaseName: "releaseName", environment: "environment", transaction: "transaction", userSegment: nil, sampleRate: nil)
+        let traceContext = SentryTraceContext(trace: SentryId(), publicKey: "publicKey", releaseName: "releaseName", environment: "environment", transaction: "transaction", userSegment: nil, sampleRate: nil, sampled: nil)
 
         let envelopeHeader = SentryEnvelopeHeader(id: eventId, traceContext: traceContext)
         XCTAssertEqual(eventId, envelopeHeader.eventId)

Tests/SentryTests/Transaction/SentryBaggageTests.swift

@@ -4,19 +4,19 @@ import XCTest
 
 class SentryBaggageTests: XCTestCase {
     func test_baggageToHeader() {
-        let header = SentryBaggage(trace: SentryId.empty, publicKey: "publicKey", releaseName: "release name", environment: "teste", transaction: "transaction", userSegment: "test user", sampleRate: "0.49").toHTTPHeader()
+        let header = SentryBaggage(trace: SentryId.empty, publicKey: "publicKey", releaseName: "release name", environment: "teste", transaction: "transaction", userSegment: "test user", sampleRate: "0.49", sampled: "true").toHTTPHeader()
 
-        XCTAssertEqual(header, "sentry-environment=teste,sentry-public_key=publicKey,sentry-release=release%20name,sentry-sample_rate=0.49,sentry-trace_id=00000000000000000000000000000000,sentry-transaction=transaction,sentry-user_segment=test%20user")
+        XCTAssertEqual(header, "sentry-environment=teste,sentry-public_key=publicKey,sentry-release=release%20name,sentry-sample_rate=0.49,sentry-sampled=true,sentry-trace_id=00000000000000000000000000000000,sentry-transaction=transaction,sentry-user_segment=test%20user")
     }
 
     func test_baggageToHeader_AppendToOriginal() {
-        let header = SentryBaggage(trace: SentryId.empty, publicKey: "publicKey", releaseName: "release name", environment: "teste", transaction: "transaction", userSegment: "test user", sampleRate: "0.49").toHTTPHeader(withOriginalBaggage: ["a": "a", "sentry-trace_id": "to-be-overwritten"])
+        let header = SentryBaggage(trace: SentryId.empty, publicKey: "publicKey", releaseName: "release name", environment: "teste", transaction: "transaction", userSegment: "test user", sampleRate: "0.49", sampled: "true").toHTTPHeader(withOriginalBaggage: ["a": "a", "sentry-trace_id": "to-be-overwritten"])
 
-        XCTAssertEqual(header, "a=a,sentry-environment=teste,sentry-public_key=publicKey,sentry-release=release%20name,sentry-sample_rate=0.49,sentry-trace_id=00000000000000000000000000000000,sentry-transaction=transaction,sentry-user_segment=test%20user")
+        XCTAssertEqual(header, "a=a,sentry-environment=teste,sentry-public_key=publicKey,sentry-release=release%20name,sentry-sample_rate=0.49,sentry-sampled=true,sentry-trace_id=00000000000000000000000000000000,sentry-transaction=transaction,sentry-user_segment=test%20user")
     }
 
     func test_baggageToHeader_onlyTrace_ignoreNils() {
-        let header = SentryBaggage(trace: SentryId.empty, publicKey: "publicKey", releaseName: nil, environment: nil, transaction: nil, userSegment: nil, sampleRate: nil).toHTTPHeader()
+        let header = SentryBaggage(trace: SentryId.empty, publicKey: "publicKey", releaseName: nil, environment: nil, transaction: nil, userSegment: nil, sampleRate: nil, sampled: nil).toHTTPHeader()
 
         XCTAssertEqual(header, "sentry-public_key=publicKey,sentry-trace_id=00000000000000000000000000000000")
     }

Tests/SentryTests/Transaction/SentryTraceStateTests.swift

@@ -18,6 +18,7 @@ class SentryTraceContextTests: XCTestCase {
         let publicKey = "SentrySessionTrackerTests"
         let releaseName = "SentrySessionTrackerIntegrationTests"
         let environment = "debug"
+        let sampled = "true"
 
         init() {
             options = Options()
@@ -26,8 +27,8 @@ class SentryTraceContextTests: XCTestCase {
             options.environment = environment
             options.sendDefaultPii = true
 
-            tracer = SentryTracer(transactionContext: TransactionContext(name: transactionName, operation: transactionOperation), hub: nil)
-            
+            tracer = SentryTracer(transactionContext: TransactionContext(name: transactionName, operation: transactionOperation, sampled: .yes), hub: nil)
+
             scope = Scope()
             scope.setUser(User(userId: userId))
             scope.userObject?.segment = userSegment
@@ -57,7 +58,8 @@ class SentryTraceContextTests: XCTestCase {
             environment: fixture.environment,
             transaction: fixture.transactionName,
             userSegment: fixture.userSegment,
-            sampleRate: fixture.sampleRate)
+            sampleRate: fixture.sampleRate,
+            sampled: fixture.sampled)
 
         assertTraceState(traceContext: traceContext)
     }
@@ -72,6 +74,13 @@ class SentryTraceContextTests: XCTestCase {
         let traceContext = SentryTraceContext(tracer: fixture.tracer, scope: fixture.scope, options: fixture.options)
         assertTraceState(traceContext: traceContext!)
     }
+
+    func testInitWithTracerNotSampled() {
+        let tracer = fixture.tracer
+        tracer.sampled = .no
+        let traceContext = SentryTraceContext(tracer: tracer, scope: fixture.scope, options: fixture.options)
+        XCTAssertEqual(traceContext?.sampled, "false")
+    }
 
     func testInitNil() {
         fixture.scope.span = nil
@@ -87,7 +96,8 @@ class SentryTraceContextTests: XCTestCase {
             environment: fixture.environment,
             transaction: fixture.transactionName,
             userSegment: fixture.userSegment,
-            sampleRate: fixture.sampleRate)
+            sampleRate: fixture.sampleRate,
+            sampled: fixture.sampled)
 
         let baggage = traceContext.toBaggage()
 
@@ -97,6 +107,7 @@ class SentryTraceContextTests: XCTestCase {
         XCTAssertEqual(baggage.environment, fixture.environment)
         XCTAssertEqual(baggage.userSegment, fixture.userSegment)
         XCTAssertEqual(baggage.sampleRate, fixture.sampleRate)
+        XCTAssertEqual(baggage.sampled, fixture.sampled)
     }
 
     func assertTraceState(traceContext: SentryTraceContext) {
@@ -106,6 +117,7 @@ class SentryTraceContextTests: XCTestCase {
         XCTAssertEqual(traceContext.environment, fixture.environment)
         XCTAssertEqual(traceContext.transaction, fixture.transactionName)
         XCTAssertEqual(traceContext.userSegment, fixture.userSegment)
+        XCTAssertEqual(traceContext.sampled, fixture.sampled)
     }
 
 }