[Tracing] Update the default value of DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED to true (#6751)

zacharycmontoya · andrewlock · ddyurchenko · commit 0667bea8fa4c · 2025-03-31T11:11:15.000+02:00
Updates the default value of the `DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED` configuration from `false` to
`true`.

Before: Automatic logs injection, by default, injects the trace-id as a decimal number representing the lower 64-bits of the trace-id, regardless if the trace-id had a 128-bit or 64-bit value.

Now: Automatic logs injection, by default, injects the trace-id as a 32-character hexadecimal number representing the 128-bit value when the trace-id is a 128-bit value and as a decimal number (same as before) when the trace-id is a 64-bit value.

This also implements a new behavior so when `DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED=false`, then `DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED` will also be configured to `false`, unless explicitly overridden by user configuration.

---------

Co-authored-by: Andrew Lock &lt;andrew.lock@datadoghq.com&gt;
diff --git a/tracer/src/Datadog.Trace/Configuration/ConfigurationKeys.cs b/tracer/src/Datadog.Trace/Configuration/ConfigurationKeys.cs
@@ -803,8 +803,11 @@ internal static class FeatureFlags
             /// <summary>
             /// Enables injecting 128-bit trace ids into logs as a hexadecimal string.
             /// If disabled, 128-bit trace ids will be truncated to the lower 64 bits,
-            /// and all trace ids will be injected as decimal strings
-            /// Default value is <c>false</c> (disabled).
+            /// and injected as decimal strings. 64-bit trace ids are
+            /// always injected as decimal strings, regardless of this setting.
+            /// Default value is <c>true</c> (enabled).
+            /// If <see cref="ConfigurationKeys.FeatureFlags.TraceId128BitGenerationEnabled"/> is set to <c>false</c>,
+            /// this setting will also be set to <c>false</c>.
             /// </summary>
             public const string TraceId128BitLoggingEnabled = "DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED";
 
diff --git a/tracer/src/Datadog.Trace/Configuration/TracerSettings.cs b/tracer/src/Datadog.Trace/Configuration/TracerSettings.cs
@@ -664,7 +664,7 @@ _ when x.ToBoolean() is { } boolean => boolean,
                                             .AsBool(true);
             TraceId128BitLoggingEnabled = config
                                          .WithKeys(ConfigurationKeys.FeatureFlags.TraceId128BitLoggingEnabled)
-                                         .AsBool(false);
+                                         .AsBool(TraceId128BitGenerationEnabled);
 
             CommandsCollectionEnabled = config
                                        .WithKeys(ConfigurationKeys.FeatureFlags.CommandsCollectionEnabled)
diff --git a/tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/LogsInjectionTestBase.cs b/tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/LogsInjectionTestBase.cs
@@ -97,7 +97,7 @@ public void ValidateLogCorrelation(
             string packageVersion = "",
             bool disableLogCorrelation = false,
             Func<string, bool> additionalInjectedLogFilter = null,
-            bool use128Bits = false)
+            bool use128Bits = true)
         {
             foreach (var test in logFileTestCases)
             {
diff --git a/tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/VersionConflict/ILoggerVersionConflict2xTests.cs b/tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/VersionConflict/ILoggerVersionConflict2xTests.cs
@@ -30,6 +30,13 @@ public ILoggerVersionConflict2xTests(ITestOutputHelper output)
         {
             SetServiceVersion("1.0.0");
             SetEnvironmentVariable("DD_LOGS_INJECTION", "true");
+
+            // When doing log injection for CI, only emit 64-bit trace-ids.
+            // By default, the version conflict results in both 64-bit trace-ids
+            // and 128-bit trace-ids, which complicates the log correlation validation.
+            // If we can remove the netcoreapp2.1 test application, then we can remove this
+            // and start root spans with the automatic tracer so that we always generate 128-bit trace-ids.
+            SetEnvironmentVariable("DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED", "false");
         }
 
         [SkippableFact]
@@ -58,7 +65,7 @@ public async Task InjectsLogs()
                 var spans = agent.WaitForSpans(1, 2500);
                 spans.Should().HaveCountGreaterOrEqualTo(1);
 
-                ValidateLogCorrelation(spans, _logFiles, expectedCorrelatedTraceCount, expectedCorrelatedSpanCount);
+                ValidateLogCorrelation(spans, _logFiles, expectedCorrelatedTraceCount, expectedCorrelatedSpanCount, use128Bits: false);
             }
         }
     }
diff --git a/tracer/test/Datadog.Trace.ClrProfiler.Managed.Tests/AutoInstrumentation/Logging/ILogger/DatadogLoggingScopeTests.cs b/tracer/test/Datadog.Trace.ClrProfiler.Managed.Tests/AutoInstrumentation/Logging/ILogger/DatadogLoggingScopeTests.cs
@@ -1,4 +1,4 @@
-﻿// <copyright file="DatadogLoggingScopeTests.cs" company="Datadog">
+// <copyright file="DatadogLoggingScopeTests.cs" company="Datadog">
 // Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.
 // This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.
 // </copyright>
@@ -50,7 +50,7 @@ public void OutputsJsonFormattedStringWhenActiveTrace()
 
             var actual = scope.ToString();
 
-            var expected = @$"dd_service:""TestService"", dd_env:""test"", dd_version:""1.2.3"", dd_trace_id:""{spanScope.Span.TraceId}"", dd_span_id:""{spanScope.Span.SpanId}""";
+            var expected = @$"dd_service:""TestService"", dd_env:""test"", dd_version:""1.2.3"", dd_trace_id:""{((Span)spanScope.Span).TraceId128}"", dd_span_id:""{spanScope.Span.SpanId}""";
             actual.Should().Be(expected);
         }
     }
diff --git a/tracer/test/Datadog.Trace.Tests/Configuration/ConfigurationSourceTests.cs b/tracer/test/Datadog.Trace.Tests/Configuration/ConfigurationSourceTests.cs
@@ -90,7 +90,7 @@ public ConfigurationSourceTests()
             yield return (s => s.ServiceNameMappings, new string[0]);
 
             yield return (s => s.TraceId128BitGenerationEnabled, true);
-            yield return (s => s.TraceId128BitLoggingEnabled, false);
+            yield return (s => s.TraceId128BitLoggingEnabled, true);
         }
 
         public static IEnumerable<(string Key, string Value, Func<TracerSettings, object> Getter, object Expected)> GetBreakingChangeTestData()
diff --git a/tracer/test/Datadog.Trace.Tests/Configuration/TracerSettingsTests.cs b/tracer/test/Datadog.Trace.Tests/Configuration/TracerSettingsTests.cs
@@ -1050,10 +1050,13 @@ public void TraceId128BitGenerationEnabled(string value, bool expected)
             var settings = new TracerSettings(source);
 
             settings.TraceId128BitGenerationEnabled.Should().Be(expected);
+
+            // Additional behavior: Ensure that TraceId128BitLoggingEnabled is configured to the same value as TraceId128BitGenerationEnabled
+            settings.TraceId128BitLoggingEnabled.Should().Be(expected);
         }
 
         [Theory]
-        [MemberData(nameof(BooleanTestCases), false)]
+        [MemberData(nameof(BooleanTestCases), true)]
         public void TraceId128BitLoggingEnabled(string value, bool expected)
         {
             var source = CreateConfigurationSource((ConfigurationKeys.FeatureFlags.TraceId128BitLoggingEnabled, value));
diff --git a/tracer/test/test-applications/integrations/dependency-libs/LogsInjectionHelper.VersionConflict/LoggingMethods.cs b/tracer/test/test-applications/integrations/dependency-libs/LogsInjectionHelper.VersionConflict/LoggingMethods.cs
@@ -17,56 +17,68 @@ public static int RunLoggingProcedure(Action<string> logAction)
         {
             try
             {
-                logAction($"{ExcludeMessagePrefix}Starting manual1 Datadog scope.");
-                using (Tracer.Instance.StartActive("manual1"))
+                logAction($"{ExcludeMessagePrefix}Starting scopes.");
+
+                // Start a trace using the latest automatic tracer so that we
+                // automatically create a 128-bit trace-id and properly set the _dd.p.tid tag.
+                // This is only done to make the testing logic easier, since all of the trace-id's
+                // will have 128-bit trace-id's.
+                //
+                // Note: This is not necessary for real applications, as the backend will still be able to
+                // correlate the 64-bit trace-id's from the manual side and the 128-bit trace-id's
+                // from the automatic side.
+                using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic0"))
                 {
-                    logAction($"Trace: manual1");
-                    using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic2"))
+                    using (Tracer.Instance.StartActive("manual1"))
                     {
-                        logAction($"Trace: manual1-automatic2");
-                        using (Tracer.Instance.StartActive("manual3"))
+                        logAction($"Trace: manual1");
+                        using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic2"))
                         {
-                            logAction($"Trace: manual1-automatic2-manual3");
-                            using (Tracer.Instance.StartActive("manual4"))
+                            logAction($"Trace: manual1-automatic2");
+                            using (Tracer.Instance.StartActive("manual3"))
                             {
-                                logAction($"Trace: manual1-automatic2-manual3-manual4");
-
-                                using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic5"))
+                                logAction($"Trace: manual1-automatic2-manual3");
+                                using (Tracer.Instance.StartActive("manual4"))
                                 {
-                                    logAction($"Trace: manual1-automatic2-manual3-manual4-automatic5");
-                                }
+                                    logAction($"Trace: manual1-automatic2-manual3-manual4");
 
-                                logAction($"Trace: manual1-automatic2-manual3-manual4");
-                            }
+                                    using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic5"))
+                                    {
+                                        logAction($"Trace: manual1-automatic2-manual3-manual4-automatic5");
+                                    }
 
-                            logAction($"Trace: manual1-automatic2-manual3");
+                                    logAction($"Trace: manual1-automatic2-manual3-manual4");
+                                }
 
-                            using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic4"))
-                            {
-                                logAction($"Trace: manual1-automatic2-manual3-automatic4");
-                                using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic5"))
+                                logAction($"Trace: manual1-automatic2-manual3");
+
+                                using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic4"))
                                 {
-                                    logAction($"Trace: manual1-automatic2-manual3-automatic4-automatic5");
-                                    using (Tracer.Instance.StartActive("manual6"))
+                                    logAction($"Trace: manual1-automatic2-manual3-automatic4");
+                                    using (TracerUtils.StartAutomaticTraceHigherAssemblyVersion("automatic5"))
                                     {
-                                        logAction($"Trace: manual1-automatic2-manual3-automatic4-automatic5-manual6");
+                                        logAction($"Trace: manual1-automatic2-manual3-automatic4-automatic5");
+                                        using (Tracer.Instance.StartActive("manual6"))
+                                        {
+                                            logAction($"Trace: manual1-automatic2-manual3-automatic4-automatic5-manual6");
+                                        }
+
+                                        logAction($"Trace: manual1-automatic2-manual3-automatic4-automatic5");
                                     }
 
-                                    logAction($"Trace: manual1-automatic2-manual3-automatic4-automatic5");
+                                    logAction($"Trace: manual1-automatic2-manual3-automatic4");
                                 }
 
-                                logAction($"Trace: manual1-automatic2-manual3-automatic4");
+                                logAction($"Trace: manual1-automatic2-manual3");
                             }
-
-                            logAction($"Trace: manual1-automatic2-manual3");
+                            logAction($"Trace: manual1-automatic2");
                         }
-                        logAction($"Trace: manual1-automatic2");
-                    }
 
-                    logAction($"Trace: manual1");
+                        logAction($"Trace: manual1");
+                    }
                 }
 
-                logAction($"{ExcludeMessagePrefix}Exited manual1 Datadog scope.");
+                logAction($"{ExcludeMessagePrefix}Exited scopes.");
             }
             catch (Exception ex)
             {

Original file line number	Diff line number	Diff line change
`@@ -97,7 +97,7 @@ public void ValidateLogCorrelation(`
`97`	`97`	`string packageVersion = "",`
`98`	`98`	`bool disableLogCorrelation = false,`
`99`	`99`	`Func<string, bool> additionalInjectedLogFilter = null,`
`100`		`- bool use128Bits = false)`
	`100`	`+ bool use128Bits = true)`
`101`	`101`	`{`
`102`	`102`	`foreach (var test in logFileTestCases)`
`103`	`103`	`{`
Original file line number	Diff line number	Diff line change
`@@ -30,6 +30,13 @@ public ILoggerVersionConflict2xTests(ITestOutputHelper output)`
`30`	`30`	`{`
`31`	`31`	`SetServiceVersion("1.0.0");`
`32`	`32`	`SetEnvironmentVariable("DD_LOGS_INJECTION", "true");`
	`33`	`+`
	`34`	`+ // When doing log injection for CI, only emit 64-bit trace-ids.`
	`35`	`+ // By default, the version conflict results in both 64-bit trace-ids`
	`36`	`+ // and 128-bit trace-ids, which complicates the log correlation validation.`
	`37`	`+ // If we can remove the netcoreapp2.1 test application, then we can remove this`
	`38`	`+ // and start root spans with the automatic tracer so that we always generate 128-bit trace-ids.`
	`39`	`+ SetEnvironmentVariable("DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED", "false");`
`33`	`40`	`}`
`34`	`41`
`35`	`42`	`[SkippableFact]`
`@@ -58,7 +65,7 @@ public async Task InjectsLogs()`
`58`	`65`	`var spans = agent.WaitForSpans(1, 2500);`
`59`	`66`	`spans.Should().HaveCountGreaterOrEqualTo(1);`
`60`	`67`
`61`		`- ValidateLogCorrelation(spans, _logFiles, expectedCorrelatedTraceCount, expectedCorrelatedSpanCount);`
	`68`	`+ ValidateLogCorrelation(spans, _logFiles, expectedCorrelatedTraceCount, expectedCorrelatedSpanCount, use128Bits: false);`
`62`	`69`	`}`
`63`	`70`	`}`
`64`	`71`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-// <copyright file="DatadogLoggingScopeTests.cs" company="Datadog">`
	`1`	`+// <copyright file="DatadogLoggingScopeTests.cs" company="Datadog">`
`2`	`2`	`// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.`
`3`	`3`	`// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.`
`4`	`4`	`// </copyright>`
`@@ -50,7 +50,7 @@ public void OutputsJsonFormattedStringWhenActiveTrace()`
`50`	`50`
`51`	`51`	`var actual = scope.ToString();`
`52`	`52`
`53`		`- var expected = @$"dd_service:""TestService"", dd_env:""test"", dd_version:""1.2.3"", dd_trace_id:""{spanScope.Span.TraceId}"", dd_span_id:""{spanScope.Span.SpanId}""";`
	`53`	`+ var expected = @$"dd_service:""TestService"", dd_env:""test"", dd_version:""1.2.3"", dd_trace_id:""{((Span)spanScope.Span).TraceId128}"", dd_span_id:""{spanScope.Span.SpanId}""";`
`54`	`54`	`actual.Should().Be(expected);`
`55`	`55`	`}`
`56`	`56`	`}`
Original file line number	Diff line number	Diff line change
`@@ -90,7 +90,7 @@ public ConfigurationSourceTests()`
`90`	`90`	`yield return (s => s.ServiceNameMappings, new string[0]);`
`91`	`91`
`92`	`92`	`yield return (s => s.TraceId128BitGenerationEnabled, true);`
`93`		`- yield return (s => s.TraceId128BitLoggingEnabled, false);`
	`93`	`+ yield return (s => s.TraceId128BitLoggingEnabled, true);`
`94`	`94`	`}`
`95`	`95`
`96`	`96`	`public static IEnumerable<(string Key, string Value, Func<TracerSettings, object> Getter, object Expected)> GetBreakingChangeTestData()`
Original file line number	Diff line number	Diff line change
`@@ -1050,10 +1050,13 @@ public void TraceId128BitGenerationEnabled(string value, bool expected)`
`1050`	`1050`	`var settings = new TracerSettings(source);`
`1051`	`1051`
`1052`	`1052`	`settings.TraceId128BitGenerationEnabled.Should().Be(expected);`
	`1053`	`+`
	`1054`	`+ // Additional behavior: Ensure that TraceId128BitLoggingEnabled is configured to the same value as TraceId128BitGenerationEnabled`
	`1055`	`+ settings.TraceId128BitLoggingEnabled.Should().Be(expected);`
`1053`	`1056`	`}`
`1054`	`1057`
`1055`	`1058`	`[Theory]`
`1056`		`- [MemberData(nameof(BooleanTestCases), false)]`
	`1059`	`+ [MemberData(nameof(BooleanTestCases), true)]`
`1057`	`1060`	`public void TraceId128BitLoggingEnabled(string value, bool expected)`
`1058`	`1061`	`{`
`1059`	`1062`	`var source = CreateConfigurationSource((ConfigurationKeys.FeatureFlags.TraceId128BitLoggingEnabled, value));`