Encode the last seen Datadog span ID within tracestate (#7067)

am312 · web-flow · commit bff441bbdf82 · 2024-06-07T11:42:08.000-04:00
w3c phase 2 support
diff --git a/dd-java-agent/instrumentation/opentelemetry/opentelemetry-0.3/src/test/groovy/OpenTelemetryTest.groovy b/dd-java-agent/instrumentation/opentelemetry/opentelemetry-0.3/src/test/groovy/OpenTelemetryTest.groovy
@@ -274,7 +274,7 @@ class OpenTelemetryTest extends AgentTestRunner {
     def expectedTraceparent = "00-${span.delegate.traceId.toHexStringPadded(32)}" +
       "-${DDSpanId.toHexStringPadded(span.delegate.spanId)}" +
       "-" + (propagatedPriority > 0 ? "01" : "00")
-    def expectedTracestate = "dd=s:${propagatedPriority}"
+    def expectedTracestate = "dd=s:${propagatedPriority};p:${DDSpanId.toHexStringPadded(span.delegate.spanId)}"
     def expectedDatadogTags = null
     if (propagatedMechanism != UNKNOWN) {
       expectedDatadogTags = "_dd.p.dm=-" + propagatedMechanism
diff --git a/dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.4/src/test/groovy/opentelemetry14/context/propagation/W3cLastParentIdTest.groovy b/dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.4/src/test/groovy/opentelemetry14/context/propagation/W3cLastParentIdTest.groovy
@@ -0,0 +1,24 @@
+package opentelemetry14.context.propagation
+
+import static datadog.trace.api.sampling.PrioritySampling.SAMPLER_KEEP
+
+class W3cLastParentIdTest extends AgentPropagatorTest {
+  @Override
+  String style() {
+    return 'tracecontext'
+  }
+
+  @Override
+  def values() {
+    // spotless:off
+    return [
+      [['traceparent': '00-11111111111111111111111111111111-2222222222222222-01','tracestate': 'dd=s:2;p:1948e0b51aee0bfa'], '11111111111111111111111111111111', '2222222222222222', SAMPLER_KEEP]
+    ]
+    // spotless:on
+  }
+
+  @Override
+  void assertInjectedHeaders(Map<String, String> headers, String traceId, String spanId, byte sampling) {
+    assert headers['tracestate'].contains("p:1948e0b51aee0bfa")
+  }
+}
diff --git a/dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.4/src/test/groovy/opentelemetry14/context/propagation/W3cPropagatorTest.groovy b/dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.4/src/test/groovy/opentelemetry14/context/propagation/W3cPropagatorTest.groovy
@@ -23,5 +23,7 @@ class W3cPropagatorTest extends AgentPropagatorTest {
   void assertInjectedHeaders(Map<String, String> headers, String traceId, String spanId, byte sampling) {
     def traceFlags = sampling == SAMPLER_KEEP ? '01' : '00'
     assert headers['traceparent'] == "00-$traceId-$spanId-$traceFlags"
+    // 'p:' not expected in tracestate here because 'p' is not supplied in values()
+    assert !headers['tracestate'].contains("p:")
   }
 }
diff --git a/dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.4/src/test/groovy/opentelemetry14/context/propagation/W3cPropagatorTracestateTest.groovy b/dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.4/src/test/groovy/opentelemetry14/context/propagation/W3cPropagatorTracestateTest.groovy
@@ -55,18 +55,16 @@ class W3cPropagatorTracestateTest extends AgentTestRunner {
     // Check tracestate contains extracted members plus the Datadog one in first position
     def injectedMembers = injectedTracestate.split(',')
     injectedMembers.length == Math.min(1 + members.length, 32)
-    injectedMembers[0] == "dd=s:0;t.tid:1111111111111111"
+    injectedMembers[0] == expect
     for (int i = 0; i< Math.min(members.length, 31); i++) {
       assert injectedMembers[i+1] == members[i]
     }
 
     where:
-    // spotless:off
-    tracestate << [
-      "foo=1,bar=2",
-      "dd=s:0,foo=1,bar=2",
-      "foo=1,dd=s:0,bar=2",
-    ]
-    // spotless:on
+    tracestate            |expect
+    "foo=1,bar=2"         |"dd=s:0;t.tid:1111111111111111"
+    "dd=s:0,foo=1,bar=2"  |"dd=s:0;t.tid:1111111111111111"
+    "foo=1,dd=s:0,bar=2"  |"dd=s:0;t.tid:1111111111111111"
+    "dd=s:3"              |"dd=s:0;t.tid:1111111111111111"
   }
 }
diff --git a/dd-java-agent/instrumentation/opentracing/api-0.31/src/test/groovy/OpenTracing31Test.groovy b/dd-java-agent/instrumentation/opentracing/api-0.31/src/test/groovy/OpenTracing31Test.groovy
@@ -280,7 +280,7 @@ class OpenTracing31Test extends AgentTestRunner {
     def expectedTraceparent = "00-${context.delegate.traceId.toHexStringPadded(32)}" +
       "-${DDSpanId.toHexStringPadded(context.delegate.spanId)}" +
       "-" + (propagatedPriority > 0 ? "01" : "00")
-    def expectedTracestate = "dd=s:${propagatedPriority}"
+    def expectedTracestate = "dd=s:${propagatedPriority};p:${DDSpanId.toHexStringPadded(context.delegate.spanId)}"
     def expectedDatadogTags = null
     if (propagatedPriority > 0) {
       def effectiveSamplingMechanism = contextPriority == UNSET ? AGENT_RATE : samplingMechanism
diff --git a/dd-java-agent/instrumentation/opentracing/api-0.32/src/test/groovy/OpenTracing32Test.groovy b/dd-java-agent/instrumentation/opentracing/api-0.32/src/test/groovy/OpenTracing32Test.groovy
@@ -295,7 +295,7 @@ class OpenTracing32Test extends AgentTestRunner {
     def expectedTraceparent = "00-${context.delegate.traceId.toHexStringPadded(32)}" +
       "-${DDSpanId.toHexStringPadded(context.delegate.spanId)}" +
       "-" + (propagatedPriority > 0 ? "01" : "00")
-    def expectedTracestate = "dd=s:${propagatedPriority}"
+    def expectedTracestate = "dd=s:${propagatedPriority};p:${DDSpanId.toHexStringPadded(context.delegate.spanId)}"
     def expectedDatadogTags = null
     if (propagatedPriority > 0) {
       def effectiveSamplingMechanism = contextPriority == UNSET ? AGENT_RATE : samplingMechanism
diff --git a/dd-java-agent/testing/src/main/groovy/datadog/trace/agent/test/asserts/TagsAssert.groovy b/dd-java-agent/testing/src/main/groovy/datadog/trace/agent/test/asserts/TagsAssert.groovy
@@ -68,6 +68,7 @@ class TagsAssert {
     assertedTags.add(DDTags.DD_ENTRY_METHOD_SIGNATURE)
     assertedTags.add(DDTags.DSM_ENABLED)
     assertedTags.add(DDTags.DJM_ENABLED)
+    assertedTags.add(DDTags.PARENT_ID)
 
     assert tags["thread.name"] != null
     assert tags["thread.id"] != null
diff --git a/dd-trace-api/src/main/java/datadog/trace/api/DDTags.java b/dd-trace-api/src/main/java/datadog/trace/api/DDTags.java
@@ -71,4 +71,5 @@ public class DDTags {
 
   public static final String PROFILING_CONTEXT_ENGINE = "_dd.profiling.ctx";
   public static final String BASE_SERVICE = "_dd.base_service";
+  public static final String PARENT_ID = "_dd.parent_id";
 }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java
@@ -142,6 +142,7 @@ public class DDSpanContext
   private volatile int encodedOperationName;
   private volatile int encodedResourceName;
   private volatile boolean requiresPostProcessing;
+  private volatile CharSequence lastParentId;
   private final boolean isRemote;
 
   /**
@@ -373,6 +374,7 @@ public DDSpanContext(
     if (samplingPriority != PrioritySampling.UNSET) {
       setSamplingPriority(samplingPriority, SamplingMechanism.UNKNOWN);
     }
+    setLastParentId(this.propagationTags.getLastParentId());
     this.isRemote = isRemote;
   }
 
@@ -1015,6 +1017,19 @@ public boolean isRequiresPostProcessing() {
     return requiresPostProcessing;
   }
 
+  public CharSequence getLastParentId() {
+    return lastParentId;
+  }
+
+  public void setLastParentId(CharSequence lastParentId) {
+    if (lastParentId != null) {
+      synchronized (unsafeTags) {
+        unsafeSetTag("_dd.parent_id", lastParentId);
+      }
+      this.lastParentId = lastParentId;
+    }
+  }
+
   public boolean isRemote() {
     return isRemote;
   }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/propagation/ContextInterpreter.java b/dd-trace-core/src/main/java/datadog/trace/core/propagation/ContextInterpreter.java
@@ -44,6 +44,7 @@ public abstract class ContextInterpreter implements AgentPropagation.KeyClassifi
   protected Map<String, String> tags;
   protected Map<String, String> baggage;
 
+  protected CharSequence lastParentId;
   protected CharSequence origin;
   protected long endToEndStartTime;
   protected boolean valid;
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/propagation/PropagationTags.java b/dd-trace-core/src/main/java/datadog/trace/core/propagation/PropagationTags.java
@@ -66,6 +66,10 @@ public interface Factory {
 
   public abstract void updateTraceIdHighOrderBits(long highOrderBits);
 
+  public abstract CharSequence getLastParentId();
+
+  public abstract void updateLastParentId(CharSequence lastParentId);
+
   /**
    * Gets the original <a href="https://www.w3.org/TR/trace-context/#tracestate-header">W3C
    * tracestate header</a> value.
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/propagation/W3CHttpCodec.java b/dd-trace-core/src/main/java/datadog/trace/core/propagation/W3CHttpCodec.java
@@ -83,6 +83,17 @@ private <C> void injectTraceParent(
     private <C> void injectTraceState(
         DDSpanContext context, C carrier, AgentPropagation.Setter<C> setter) {
       PropagationTags propagationTags = context.getPropagationTags();
+      if (propagationTags.getLastParentId() == null) {
+        if (context.isRemote()) {
+          CharSequence lastParentId = context.getLastParentId();
+          if (lastParentId != null) {
+            propagationTags.updateLastParentId(lastParentId);
+          }
+        } else {
+          propagationTags.updateLastParentId(DDSpanId.toHexStringPadded(context.getSpanId()));
+        }
+      }
+
       String tracestate = propagationTags.headerValue(W3C);
       if (tracestate != null && !tracestate.isEmpty()) {
         setter.set(carrier, TRACE_STATE_KEY, tracestate);
@@ -323,6 +334,7 @@ void parseTraceStateHeader(String tracestate) {
       } else {
         this.propagationTags = this.propagationTagsFactory.fromHeaderValue(W3C, tracestate);
       }
+      this.lastParentId = this.propagationTags.getLastParentId();
       int ptagsPriority = this.propagationTags.getSamplingPriority();
       int contextPriority = this.samplingPriority;
       if ((contextPriority == SAMPLER_DROP && ptagsPriority > 0)
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/propagation/ptags/PTagsFactory.java b/dd-trace-core/src/main/java/datadog/trace/core/propagation/ptags/PTagsFactory.java
@@ -99,12 +99,21 @@ static class PTags extends PropagationTags {
      */
     protected volatile String error;
 
+    private volatile CharSequence lastParentId;
+
     public PTags(
         PTagsFactory factory,
         List<TagElement> tagPairs,
         TagValue decisionMakerTagValue,
         TagValue traceIdTagValue) {
-      this(factory, tagPairs, decisionMakerTagValue, traceIdTagValue, PrioritySampling.UNSET, null);
+      this(
+          factory,
+          tagPairs,
+          decisionMakerTagValue,
+          traceIdTagValue,
+          PrioritySampling.UNSET,
+          null,
+          null);
     }
 
     PTags(
@@ -113,14 +122,16 @@ public PTags(
         TagValue decisionMakerTagValue,
         TagValue traceIdTagValue,
         int samplingPriority,
-        CharSequence origin) {
+        CharSequence origin,
+        CharSequence lastParentId) {
       assert tagPairs == null || tagPairs.size() % 2 == 0;
       this.factory = factory;
       this.tagPairs = tagPairs;
       this.canChangeDecisionMaker = decisionMakerTagValue == null;
       this.decisionMakerTagValue = decisionMakerTagValue;
       this.samplingPriority = samplingPriority;
       this.origin = origin;
+      this.lastParentId = lastParentId;
       if (traceIdTagValue != null) {
         CharSequence traceIdHighOrderBitsHex = traceIdTagValue.forType(TagElement.Encoding.DATADOG);
         this.traceIdHighOrderBits =
@@ -132,7 +143,7 @@ public PTags(
     }
 
     static PTags withError(PTagsFactory factory, String error) {
-      PTags pTags = new PTags(factory, null, null, null, PrioritySampling.UNSET, null);
+      PTags pTags = new PTags(factory, null, null, null, PrioritySampling.UNSET, null, null);
       pTags.error = error;
       return pTags;
     }
@@ -213,6 +224,20 @@ public void updateTraceIdHighOrderBits(long highOrderBits) {
       }
     }
 
+    @Override
+    public CharSequence getLastParentId() {
+      return lastParentId;
+    }
+
+    @Override
+    public void updateLastParentId(CharSequence lastParentId) {
+      lastParentId = "0000000000000000".equals(lastParentId) ? null : lastParentId;
+      if (!Objects.equals(this.lastParentId, lastParentId)) {
+        clearCachedHeader(W3C);
+        this.lastParentId = TagValue.from(lastParentId);
+      }
+    }
+
     @Override
     @SuppressWarnings("StringEquality")
     @SuppressFBWarnings("ES_COMPARING_STRINGS_WITH_EQ")
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/propagation/ptags/W3CPTagsCodec.java b/dd-trace-core/src/main/java/datadog/trace/core/propagation/ptags/W3CPTagsCodec.java
@@ -26,6 +26,7 @@ public class W3CPTagsCodec extends PTagsCodec {
   private static final int MIN_ALLOWED_CHAR = 32;
   private static final int MAX_ALLOWED_CHAR = 126;
   private static final int MAX_MEMBER_COUNT = 32;
+  private static final String LAST_PARENT_ZERO = "0000000000000000";
 
   @Override
   PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) {
@@ -94,6 +95,7 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) {
     TagValue decisionMakerTagValue = null;
     TagValue traceIdTagValue = null;
     int maxUnknownSize = 0;
+    CharSequence lastParentId = LAST_PARENT_ZERO;
     while (tagPos < ddMemberValueEnd) {
       int tagKeyEndsAt =
           validateCharsUntilSeparatorOrEnd(
@@ -162,6 +164,8 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) {
           samplingPriority = validateSamplingPriority(value, tagValuePos, tagValueEndsAt);
         } else if (keyLength == 1 && c == 'o') {
           origin = TagValue.from(Encoding.W3C, value, tagValuePos, tagValueEndsAt);
+        } else if (keyLength == 1 && c == 'p') {
+          lastParentId = TagValue.from(Encoding.W3C, value, tagValuePos, tagValueEndsAt);
         } else {
           if (maxUnknownSize != 0) {
             maxUnknownSize++; // delimiter
@@ -182,7 +186,8 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) {
         firstMemberStart,
         ddMemberStart,
         ddMemberValueEnd,
-        maxUnknownSize);
+        maxUnknownSize,
+        lastParentId);
   }
 
   @Override
@@ -231,6 +236,19 @@ protected int appendPrefix(StringBuilder sb, PTags ptags) {
         sb.append(origin);
       }
     }
+    // append last ParentId (p)
+    CharSequence lastParent = ptags.getLastParentId();
+    if (lastParent != null && !lastParent.equals(LAST_PARENT_ZERO)) {
+      if (sb.length() > EMPTY_SIZE) {
+        sb.append(';');
+      }
+      sb.append("p:");
+      if (lastParent instanceof TagValue) {
+        sb.append(((TagValue) lastParent).forType(Encoding.W3C));
+      } else {
+        sb.append(lastParent);
+      }
+    }
     return sb.length();
   }
 
@@ -692,7 +710,8 @@ private static W3CPTags empty(
         firstMemberStart,
         ddMemberStart,
         ddMemberValueEnd,
-        0);
+        0,
+        null);
   }
 
   private static class W3CPTags extends PTags {
@@ -722,8 +741,16 @@ public W3CPTags(
         int firstMemberStart,
         int ddMemberStart,
         int ddMemberValueEnd,
-        int maxUnknownSize) {
-      super(factory, tagPairs, decisionMakerTagValue, traceIdTagValue, samplingPriority, origin);
+        int maxUnknownSize,
+        CharSequence lastParentId) {
+      super(
+          factory,
+          tagPairs,
+          decisionMakerTagValue,
+          traceIdTagValue,
+          samplingPriority,
+          origin,
+          lastParentId);
       this.tracestate = original;
       this.firstMemberStart = firstMemberStart;
       this.ddMemberStart = ddMemberStart;
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/propagation/W3CHttpInjectorTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/propagation/W3CHttpInjectorTest.groovy
@@ -47,17 +47,15 @@ class W3CHttpInjectorTest extends DDCoreSpecification {
       null,
       NoopPathwayContext.INSTANCE,
       false,
-      PropagationTags.factory().fromHeaderValue(PropagationTags.HeaderType.DATADOG, tracestate ? "_dd.p.usr=123" : ""))
+      PropagationTags.factory().fromHeaderValue(PropagationTags.HeaderType.DATADOG, "_dd.p.usr=123"))
     final Map<String, String> carrier = [:]
     Map<String, String> expected = [
       (TRACE_PARENT_KEY)        : buildTraceParent(traceId, spanId, samplingPriority),
+      (TRACE_STATE_KEY)         : tracestate,
       (OT_BAGGAGE_PREFIX + "k1"): "v1",
       (OT_BAGGAGE_PREFIX + "k2"): "v2",
       "SOME_CUSTOM_HEADER"      : "some-value",
     ]
-    if (tracestate) {
-      expected.put(TRACE_STATE_KEY, tracestate)
-    }
 
     when:
     injector.inject(mockedContext, carrier, MapSetter.INSTANCE)
@@ -70,11 +68,11 @@ class W3CHttpInjectorTest extends DDCoreSpecification {
 
     where:
     traceId               | spanId                | samplingPriority | origin   | tracestate
-    "1"                   | "2"                   | UNSET            | null     | null
-    "1"                   | "2"                   | SAMPLER_KEEP     | "saipan" | "dd=s:1;o:saipan;t.usr:123"
-    "$TRACE_ID_MAX"       | "${TRACE_ID_MAX - 1}" | UNSET            | "saipan" | "dd=o:saipan;t.usr:123"
-    "${TRACE_ID_MAX - 1}" | "$TRACE_ID_MAX"       | SAMPLER_KEEP     | null     | "dd=s:1;t.usr:123"
-    "${TRACE_ID_MAX - 1}" | "$TRACE_ID_MAX"       | SAMPLER_DROP     | null     | "dd=s:0;t.usr:123"
+    "1"                   | "2"                   | UNSET            | null     | "dd=p:0000000000000002;t.usr:123"
+    "1"                   | "4"                   | SAMPLER_KEEP     | "saipan" | "dd=s:1;o:saipan;p:0000000000000004;t.usr:123"
+    "$TRACE_ID_MAX"       | "${TRACE_ID_MAX - 1}" | UNSET            | "saipan" | "dd=o:saipan;p:fffffffffffffffe;t.usr:123"
+    "${TRACE_ID_MAX - 1}" | "$TRACE_ID_MAX"       | SAMPLER_KEEP     | null     | "dd=s:1;p:ffffffffffffffff;t.usr:123"
+    "${TRACE_ID_MAX - 1}" | "$TRACE_ID_MAX"       | SAMPLER_DROP     | null     | "dd=s:0;p:ffffffffffffffff;t.usr:123"
   }
 
   def "inject http headers with end-to-end"() {
@@ -113,7 +111,7 @@ class W3CHttpInjectorTest extends DDCoreSpecification {
     then:
     carrier == [
       (TRACE_PARENT_KEY): buildTraceParent('1', '2', UNSET),
-      (TRACE_STATE_KEY): "dd=o:fakeOrigin;t.dm:-4;t.anytag:value",
+      (TRACE_STATE_KEY): "dd=o:fakeOrigin;p:0000000000000002;t.dm:-4;t.anytag:value",
       (OT_BAGGAGE_PREFIX + "t0"): "${(long) (mockedContext.endToEndStartTime / 1000000L)}",
       (OT_BAGGAGE_PREFIX + "k1"): "v1",
       (OT_BAGGAGE_PREFIX + "k2"): "v2",
@@ -159,7 +157,7 @@ class W3CHttpInjectorTest extends DDCoreSpecification {
     then:
     carrier == [
       (TRACE_PARENT_KEY): buildTraceParent('1', '2', USER_KEEP),
-      (TRACE_STATE_KEY): "dd=s:2;o:fakeOrigin;t.dm:-4",
+      (TRACE_STATE_KEY): "dd=s:2;o:fakeOrigin;p:0000000000000002;t.dm:-4",
       (OT_BAGGAGE_PREFIX + "k1"): "v1",
       (OT_BAGGAGE_PREFIX + "k2"): "v2",
     ]
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/propagation/W3CPropagationTagsTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/propagation/W3CPropagationTagsTest.groovy
@@ -302,7 +302,7 @@ class W3CPropagationTagsTest extends DDCoreSpecification {
     propagationTags.createTagMap() == tags
 
     where:
-    headerValue                       | priority                      | mechanism                           | origin  | expectedHeaderValue                | tags
+    headerValue                       | priority                      | mechanism                           | origin  | expectedHeaderValue                                   | tags
     'dd=s:0;o:some;t.dm:934086a686-4' | PrioritySampling.SAMPLER_KEEP | SamplingMechanism.DEFAULT           | "other" | 'dd=s:0;o:other;t.dm:934086a686-4' | ['_dd.p.dm': '934086a686-4']
     'dd=s:0;o:some;x:unknown'         | PrioritySampling.USER_KEEP    | SamplingMechanism.LOCAL_USER_RULE   | "same"  | 'dd=s:2;o:same;t.dm:-3;x:unknown'  | ['_dd.p.dm': '-3']
     'dd=s:0;o:some;x:unknown'         | PrioritySampling.USER_DROP    | SamplingMechanism.MANUAL            | null    | 'dd=s:-1;x:unknown'                | [:]
diff --git a/dd-trace-ot/src/ot31CompatibilityTest/groovy/OT31ApiTest.groovy b/dd-trace-ot/src/ot31CompatibilityTest/groovy/OT31ApiTest.groovy
diff --git a/dd-trace-ot/src/ot33CompatibilityTest/groovy/OT33ApiTest.groovy b/dd-trace-ot/src/ot33CompatibilityTest/groovy/OT33ApiTest.groovy

Original file line number	Diff line number	Diff line change
`@@ -23,5 +23,7 @@ class W3cPropagatorTest extends AgentPropagatorTest {`
`23`	`23`	`void assertInjectedHeaders(Map<String, String> headers, String traceId, String spanId, byte sampling) {`
`24`	`24`	`def traceFlags = sampling == SAMPLER_KEEP ? '01' : '00'`
`25`	`25`	`assert headers['traceparent'] == "00-$traceId-$spanId-$traceFlags"`
	`26`	`+ // 'p:' not expected in tracestate here because 'p' is not supplied in values()`
	`27`	`+ assert !headers['tracestate'].contains("p:")`
`26`	`28`	`}`
`27`	`29`	`}`
Original file line number	Diff line number	Diff line change
`@@ -71,4 +71,5 @@ public class DDTags {`
`71`	`71`
`72`	`72`	`public static final String PROFILING_CONTEXT_ENGINE = "_dd.profiling.ctx";`
`73`	`73`	`public static final String BASE_SERVICE = "_dd.base_service";`
	`74`	`+ public static final String PARENT_ID = "_dd.parent_id";`
`74`	`75`	`}`