[otlp] Export instrumentation scope attributes from ActivitySource.Tags (open-telemetry#5897)

Co-authored-by: Mikel Blanchard <[email protected]>

Author: rajkumar-rangaraj

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md

@@ -7,6 +7,10 @@ Notes](../../RELEASENOTES.md).
 
 ## Unreleased
 
+* Added support for exporting instrumentation scope attributes from
+  `ActivitySource.Tags`.
+  ([#5897](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5897))
+
 ## 1.10.0-beta.1
 
 Released 2024-Sep-30

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/ActivityExtensions.cs

@@ -32,6 +32,8 @@ internal static void AddBatch(
         };
         request.ResourceSpans.Add(resourceSpans);
 
+        var maxTags = sdkLimitOptions.AttributeCountLimit ?? int.MaxValue;
+
         foreach (var activity in activityBatch)
         {
             Span? span = activity.ToOtlpSpan(sdkLimitOptions);
@@ -44,15 +46,15 @@ internal static void AddBatch(
             }
 
             var activitySourceName = activity.Source.Name;
-            if (!spansByLibrary.TryGetValue(activitySourceName, out var spans))
+            if (!spansByLibrary.TryGetValue(activitySourceName, out var scopeSpans))
             {
-                spans = GetSpanListFromPool(activitySourceName, activity.Source.Version);
+                scopeSpans = GetSpanListFromPool(activity.Source, maxTags, sdkLimitOptions.AttributeValueLengthLimit);
 
-                spansByLibrary.Add(activitySourceName, spans);
-                resourceSpans.ScopeSpans.Add(spans);
+                spansByLibrary.Add(activitySourceName, scopeSpans);
+                resourceSpans.ScopeSpans.Add(scopeSpans);
             }
 
-            spans.Spans.Add(span);
+            scopeSpans.Spans.Add(span);
         }
     }
 
@@ -65,34 +67,69 @@ internal static void Return(this ExportTraceServiceRequest request)
             return;
         }
 
-        foreach (var scope in resourceSpans.ScopeSpans)
+        foreach (var scopeSpan in resourceSpans.ScopeSpans)
         {
-            scope.Spans.Clear();
-            SpanListPool.Add(scope);
+            scopeSpan.Spans.Clear();
+            scopeSpan.Scope.Attributes.Clear();
+            SpanListPool.Add(scopeSpan);
         }
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    internal static ScopeSpans GetSpanListFromPool(string name, string? version)
+    internal static ScopeSpans GetSpanListFromPool(ActivitySource activitySource, int maxTags, int? attributeValueLengthLimit)
     {
-        if (!SpanListPool.TryTake(out var spans))
+        if (!SpanListPool.TryTake(out var scopeSpans))
         {
-            spans = new ScopeSpans
+            scopeSpans = new ScopeSpans
             {
                 Scope = new InstrumentationScope
                 {
-                    Name = name, // Name is enforced to not be null, but it can be empty.
-                    Version = version ?? string.Empty, // NRE throw by proto
+                    Name = activitySource.Name, // Name is enforced to not be null, but it can be empty.
+                    Version = activitySource.Version ?? string.Empty, // NRE throw by proto
                 },
             };
         }
         else
         {
-            spans.Scope.Name = name;
-            spans.Scope.Version = version ?? string.Empty;
+            scopeSpans.Scope.Name = activitySource.Name; // Name is enforced to not be null, but it can be empty.
+            scopeSpans.Scope.Version = activitySource.Version ?? string.Empty; // NRE throw by proto
+        }
+
+        if (activitySource.Tags != null)
+        {
+            var scopeAttributes = scopeSpans.Scope.Attributes;
+
+            if (activitySource.Tags is IReadOnlyList<KeyValuePair<string, object?>> activitySourceTagsList)
+            {
+                for (int i = 0; i < activitySourceTagsList.Count; i++)
+                {
+                    if (scopeAttributes.Count < maxTags)
+                    {
+                        OtlpTagWriter.Instance.TryWriteTag(ref scopeAttributes, activitySourceTagsList[i], attributeValueLengthLimit);
+                    }
+                    else
+                    {
+                        scopeSpans.Scope.DroppedAttributesCount++;
+                    }
+                }
+            }
+            else
+            {
+                foreach (var tag in activitySource.Tags)
+                {
+                    if (scopeAttributes.Count < maxTags)
+                    {
+                        OtlpTagWriter.Instance.TryWriteTag(ref scopeAttributes, tag, attributeValueLengthLimit);
+                    }
+                    else
+                    {
+                        scopeSpans.Scope.DroppedAttributesCount++;
+                    }
+                }
+            }
         }
 
-        return spans;
+        return scopeSpans;
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

test/OpenTelemetry.Exporter.OpenTelemetryProtocol.Tests/MockCollectorIntegrationTests.cs

@@ -75,7 +75,7 @@ public async Task TestRecoveryAfterFailedExport()
         await httpClient.GetAsync($"/MockCollector/SetResponseCodes/{string.Join(",", codes.Select(x => (int)x))}");
 
         var exportResults = new List<ExportResult>();
-        var otlpExporter = new OtlpTraceExporter(new OtlpExporterOptions() { Endpoint = new Uri($"http://localhost:{testGrpcPort}") });
+        using var otlpExporter = new OtlpTraceExporter(new OtlpExporterOptions() { Endpoint = new Uri($"http://localhost:{testGrpcPort}") });
         var delegatingExporter = new DelegatingExporter<Activity>
         {
             OnExportFunc = (batch) =>
@@ -183,7 +183,7 @@ public async Task GrpcRetryTests(bool useRetryTransmissionHandler, ExportResult
          .AddInMemoryCollection(new Dictionary<string, string?> { [ExperimentalOptions.OtlpRetryEnvVar] = useRetryTransmissionHandler ? "in_memory" : null })
          .Build();
 
-        var otlpExporter = new OtlpTraceExporter(exporterOptions, new SdkLimitOptions(), new ExperimentalOptions(configuration));
+        using var otlpExporter = new OtlpTraceExporter(exporterOptions, new SdkLimitOptions(), new ExperimentalOptions(configuration));
 
         var activitySourceName = "otel.grpc.retry.test";
         using var source = new ActivitySource(activitySourceName);
@@ -268,7 +268,7 @@ public async Task HttpRetryTests(bool useRetryTransmissionHandler, ExportResult
          .AddInMemoryCollection(new Dictionary<string, string?> { [ExperimentalOptions.OtlpRetryEnvVar] = useRetryTransmissionHandler ? "in_memory" : null })
          .Build();
 
-        var otlpExporter = new OtlpTraceExporter(exporterOptions, new SdkLimitOptions(), new ExperimentalOptions(configuration));
+        using var otlpExporter = new OtlpTraceExporter(exporterOptions, new SdkLimitOptions(), new ExperimentalOptions(configuration));
 
         var activitySourceName = "otel.http.retry.test";
         using var source = new ActivitySource(activitySourceName);
@@ -371,7 +371,7 @@ public async Task HttpPersistentStorageRetryTests(bool usePersistentStorageTrans
             transmissionHandler = new OtlpExporterTransmissionHandler<ExportTraceServiceRequest>(exportClient, exporterOptions.TimeoutMilliseconds);
         }
 
-        var otlpExporter = new OtlpTraceExporter(exporterOptions, new(), new(), transmissionHandler);
+        using var otlpExporter = new OtlpTraceExporter(exporterOptions, new(), new(), transmissionHandler);
 
         var activitySourceName = "otel.http.persistent.storage.retry.test";
         using var source = new ActivitySource(activitySourceName);
@@ -510,7 +510,7 @@ public async Task GrpcPersistentStorageRetryTests(bool usePersistentStorageTrans
             transmissionHandler = new OtlpExporterTransmissionHandler<ExportTraceServiceRequest>(exportClient, exporterOptions.TimeoutMilliseconds);
         }
 
-        var otlpExporter = new OtlpTraceExporter(exporterOptions, new(), new(), transmissionHandler);
+        using var otlpExporter = new OtlpTraceExporter(exporterOptions, new(), new(), transmissionHandler);
 
         var activitySourceName = "otel.grpc.persistent.storage.retry.test";
         using var source = new ActivitySource(activitySourceName);