#1034: added option for configuring setting parent from SQS messages …

…batch

src/OpenTelemetry.Instrumentation.AWSLambda/.publicApi/netstandard2.0/PublicAPI.Unshipped.txt

@@ -2,6 +2,8 @@ OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaInstrumentationOptions
 OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaInstrumentationOptions.AWSLambdaInstrumentationOptions() -> void
 OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaInstrumentationOptions.DisableAwsXRayContextExtraction.get -> bool
 OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaInstrumentationOptions.DisableAwsXRayContextExtraction.set -> void
+OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaInstrumentationOptions.SetParentFromMessageBatch.get -> bool
+OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaInstrumentationOptions.SetParentFromMessageBatch.set -> void
 OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaWrapper
 OpenTelemetry.Instrumentation.AWSLambda.TracerProviderBuilderExtensions
 static OpenTelemetry.Instrumentation.AWSLambda.AWSLambdaWrapper.Trace<TInput, TResult>(OpenTelemetry.Trace.TracerProvider tracerProvider, System.Func<TInput, Amazon.Lambda.Core.ILambdaContext, TResult> lambdaHandler, TInput input, Amazon.Lambda.Core.ILambdaContext context, System.Diagnostics.ActivityContext parentContext = default(System.Diagnostics.ActivityContext)) -> TResult

src/OpenTelemetry.Instrumentation.AWSLambda/AWSLambdaInstrumentationOptions.cs

@@ -25,4 +25,10 @@ public class AWSLambdaInstrumentationOptions
     /// Gets or sets a value indicating whether AWS X-Ray context extraction should be disabled.
     /// </summary>
     public bool DisableAwsXRayContextExtraction { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether the parent Activity should be set when SQS message batch is received.
+    /// If option is set to true then the parent is set using the last received message otherwise the parent is not set at all.
+    /// </summary>
+    public bool SetParentFromMessageBatch { get; set; }
 }

src/OpenTelemetry.Instrumentation.AWSLambda/Implementation/AWSMessagingUtils.cs

@@ -32,16 +32,22 @@ internal class AWSMessagingUtils
     private const string SnsAttributeTypeStringArray = "String.Array";
     private const string SnsMessageAttributes = "MessageAttributes";
 
+    /// <summary>
+    /// Gets or sets a value indicating whether the parent Activity should be set when SQS message batch is received.
+    /// If option is set to true then the parent is set using the last received message otherwise the parent is not set at all.
+    /// </summary>
+    internal static bool SetParentFromMessageBatch { get; set; }
+
     internal static (PropagationContext ParentContext, IEnumerable<ActivityLink> Links) ExtractParentContext(SQSEvent sqsEvent)
     {
         if (sqsEvent?.Records == null)
         {
             return (default, null);
         }
 
-        // We assume there can be only one parent that's why we consider only a single (the last) record as the carrier.
-        var parentRecord = sqsEvent.Records.LastOrDefault();
-        var parentContext = ExtractParentContext(parentRecord);
+        // We choose the last message (record) as the carrier to set the parent.
+        var parentRecord = SetParentFromMessageBatch ? sqsEvent.Records.LastOrDefault() : null;
+        var parentContext = (parentRecord != null) ? ExtractParentContext(parentRecord) : default;
 
         var links = new List<ActivityLink>();
         foreach (var record in sqsEvent.Records)
@@ -80,7 +86,8 @@ internal static PropagationContext ExtractParentContext(SQSEvent.SQSMessage sqsM
 
     internal static PropagationContext ExtractParentContext(SNSEvent snsEvent)
     {
-        // We assume there can be only one parent that's why we consider only a single (the last) record as the carrier.
+        // We assume there can be only a single SNS record (message) and records list is kept in the model consistency.
+        // See https://aws.amazon.com/sns/faqs/ for details.
         var record = snsEvent?.Records?.LastOrDefault();
         return ExtractParentContext(record);
     }

src/OpenTelemetry.Instrumentation.AWSLambda/TracerProviderBuilderExtensions.cs

@@ -51,6 +51,7 @@ public static TracerProviderBuilder AddAWSLambdaConfigurations(
         configure?.Invoke(options);
 
         AWSLambdaWrapper.DisableAwsXRayContextExtraction = options.DisableAwsXRayContextExtraction;
+        AWSMessagingUtils.SetParentFromMessageBatch = options.SetParentFromMessageBatch;
 
         builder.AddSource(AWSLambdaWrapper.ActivitySourceName);
         builder.SetResourceBuilder(ResourceBuilder