[otlp] Fix incorrect length handling of Status.Description exceeding…

… 127 bytes (#6119) Co-authored-by: Mikel Blanchard <mblanchard@macrosssoftware.com>
open-telemetry · Feb 1, 2025 · 36b777b · 36b777b
1 parent cccf1ec
commit 36b777b
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Showing 3 changed files with 12 additions and 4 deletions.
diff --git a/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md b/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md
@@ -12,6 +12,10 @@ Notes](../../RELEASENOTES.md).
   exports are correctly marked as successful.
   ([#6099](https://github.com/open-telemetry/opentelemetry-dotnet/pull/6099))
 
+* Fixed an issues causing trace exports to fail when
+  `Activity.StatusDescription` exceeds 127 bytes.
+  ([#6119](https://github.com/open-telemetry/opentelemetry-dotnet/pull/6119))
+
 ## 1.11.1
 
 Released 2025-Jan-22

diff --git a/...y.Exporter.OpenTelemetryProtocol/Implementation/Serializer/ProtobufOtlpTraceSerializer.cs b/...y.Exporter.OpenTelemetryProtocol/Implementation/Serializer/ProtobufOtlpTraceSerializer.cs
@@ -507,7 +507,10 @@ internal static int WriteSpanStatus(byte[] buffer, int position, Activity activi
         {
             var descriptionSpan = description.AsSpan();
             var numberOfUtf8CharsInString = ProtobufSerializer.GetNumberOfUtf8CharsInString(descriptionSpan);
-            position = ProtobufSerializer.WriteTagAndLength(buffer, position, numberOfUtf8CharsInString + 4, ProtobufOtlpTraceFieldNumberConstants.Span_Status, ProtobufWireType.LEN);
+            var serializedLengthSize = ProtobufSerializer.ComputeVarInt64Size((ulong)numberOfUtf8CharsInString);
+
+            // length = numberOfUtf8CharsInString + Status_Message tag size + serializedLengthSize field size + Span_Status tag size + Span_Status length size.
+            position = ProtobufSerializer.WriteTagAndLength(buffer, position, numberOfUtf8CharsInString + 1 + serializedLengthSize + 2, ProtobufOtlpTraceFieldNumberConstants.Span_Status, ProtobufWireType.LEN);
             position = ProtobufSerializer.WriteStringWithTag(buffer, position, ProtobufOtlpTraceFieldNumberConstants.Status_Message, numberOfUtf8CharsInString, descriptionSpan);
         }
         else

diff --git a/test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/OtlpTraceExporterTests.cs b/test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/OtlpTraceExporterTests.cs
@@ -15,7 +15,6 @@
 using OtlpCollector = OpenTelemetry.Proto.Collector.Trace.V1;
 using OtlpCommon = OpenTelemetry.Proto.Common.V1;
 using OtlpTrace = OpenTelemetry.Proto.Trace.V1;
-using Status = OpenTelemetry.Trace.Status;
 
 namespace OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests;
 
@@ -500,7 +499,7 @@ public void ToOtlpSpanTest()
 
         Assert.NotNull(childActivity);
 
-        childActivity.SetStatus(ActivityStatusCode.Error);
+        childActivity.SetStatus(ActivityStatusCode.Error, new string('a', 150));
 
         var childEvents = new List<ActivityEvent> { new("e0"), new("e1", default, new ActivityTagsCollection(attributes)) };
         childActivity.AddEvent(childEvents[0]);
@@ -521,7 +520,7 @@ public void ToOtlpSpanTest()
         Assert.NotNull(otlpSpan.Status);
         Assert.Equal(OtlpTrace.Status.Types.StatusCode.Error, otlpSpan.Status.Code);
 
-        Assert.Equal(Status.Error.Description ?? string.Empty, otlpSpan.Status.Message);
+        Assert.Equal(childActivity.StatusDescription ?? string.Empty, otlpSpan.Status.Message);
         Assert.Empty(otlpSpan.Attributes);
 
         Assert.Equal(childEvents.Count, otlpSpan.Events.Count);
@@ -572,6 +571,7 @@ public void ToOtlpSpanActivitiesWithNullArrayTest()
     [InlineData(ActivityStatusCode.Unset, "Description will be ignored if status is Unset.")]
     [InlineData(ActivityStatusCode.Ok, "Description will be ignored if status is Okay.")]
     [InlineData(ActivityStatusCode.Error, "Description will be kept if status is Error.")]
+    [InlineData(ActivityStatusCode.Error, "150 Character String - aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")]
     public void ToOtlpSpanNativeActivityStatusTest(ActivityStatusCode expectedStatusCode, string statusDescription)
     {
         using var activitySource = new ActivitySource(nameof(this.ToOtlpSpanTest));
@@ -645,6 +645,7 @@ void RunTest(SdkLimitOptions sdkOptions, Batch<Activity> batch)
     [InlineData(StatusCode.Unset, "Unset", "Description will be ignored if status is Unset.")]
     [InlineData(StatusCode.Ok, "Ok", "Description must only be used with the Error StatusCode.")]
     [InlineData(StatusCode.Error, "Error", "Error description.")]
+    [InlineData(StatusCode.Error, "Error", "150 Character String - aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")]
     [Obsolete("Remove when ActivityExtensions status APIs are removed")]
     public void ToOtlpSpanStatusTagTest(StatusCode expectedStatusCode, string statusCodeTagValue, string statusDescription)
     {