review comments

Microsoft.Azure.Cosmos/src/Headers/Headers.cs

@@ -41,8 +41,8 @@ public virtual string ContinuationToken
         /// </summary>
         internal virtual string CorrelatedActivityId
         {
-            get => this.CosmosMessageHeaders.INameValueCollection.Get(HttpConstants.HttpHeaders.CorrelatedActivityId);
-            set => this.CosmosMessageHeaders.INameValueCollection.Set(HttpConstants.HttpHeaders.CorrelatedActivityId, value);
+            get => this.CosmosMessageHeaders.INameValueCollection?.Get(HttpConstants.HttpHeaders.CorrelatedActivityId);
+            set => this.CosmosMessageHeaders.INameValueCollection?.Set(HttpConstants.HttpHeaders.CorrelatedActivityId, value);
         }
 
         /// <summary>

Microsoft.Azure.Cosmos/src/Telemetry/OpenTelemetry/CosmosDbEventSource.cs

@@ -32,7 +32,7 @@ public static bool IsEnabled(EventLevel level)
         [NonEvent]
         public static void RecordDiagnosticsForRequests(
             DistributedTracingOptions config,
-            string operationType,
+            Documents.OperationType operationType,
             OpenTelemetryAttributes response)
         {
             if (DiagnosticsFilterHelper.IsTracingNeeded(

Microsoft.Azure.Cosmos/src/Telemetry/OpenTelemetry/Filters/DiagnosticsFilterHelper.cs

@@ -17,7 +17,7 @@ internal static class DiagnosticsFilterHelper
         /// <returns>true or false</returns>
         public static bool IsTracingNeeded(
             DistributedTracingOptions config,
-            string operationType,
+            Documents.OperationType operationType,
             OpenTelemetryAttributes response)
         {
             TimeSpan latencyThreshold;
@@ -28,7 +28,7 @@ public static bool IsTracingNeeded(
             }
             else
             {
-                latencyThreshold = operationType == OperationType.Query.ToString() ? DistributedTracingOptions.DefaultQueryTimeoutThreshold : DistributedTracingOptions.DefaultCrudLatencyThreshold;
+                latencyThreshold = operationType == OperationType.Query ? DistributedTracingOptions.DefaultQueryTimeoutThreshold : DistributedTracingOptions.DefaultCrudLatencyThreshold;
             }
 
             return response.Diagnostics.GetClientElapsedTime() > latencyThreshold || !response.StatusCode.IsSuccess();

Microsoft.Azure.Cosmos/src/Telemetry/OpenTelemetry/OpenTelemetryAttributes.cs

@@ -68,6 +68,6 @@ internal OpenTelemetryAttributes(RequestMessage requestMessage)
         /// <summary>
         /// OperationType
         /// </summary>
-        internal string OperationType { get; set; }
+        internal Documents.OperationType OperationType { get; set; }
     }
 }

Microsoft.Azure.Cosmos/src/Telemetry/OpenTelemetry/OpenTelemetryCoreRecorder.cs

@@ -15,11 +15,11 @@ namespace Microsoft.Azure.Cosmos.Telemetry
     internal struct OpenTelemetryCoreRecorder : IDisposable
     {
         private const string CosmosDb = "cosmosdb";
-
+        
         private readonly DiagnosticScope scope;
         private readonly DistributedTracingOptions config;
 
-        private readonly string operationType;
+        private readonly Documents.OperationType operationType;
         private OpenTelemetryAttributes response = null;
 
         internal static IDictionary<Type, Action<Exception, DiagnosticScope>> OTelCompatibleExceptions = new Dictionary<Type, Action<Exception, DiagnosticScope>>()
@@ -41,7 +41,7 @@ public OpenTelemetryCoreRecorder(
         {
             this.scope = scope;
             this.config = config;
-            this.operationType = operationType.ToString();
+            this.operationType = operationType;
 
             if (scope.IsEnabled)
             {
@@ -155,7 +155,8 @@ public void Dispose()
         {
             if (this.scope.IsEnabled)
             {
-                string operationType = this.response?.OperationType ?? this.operationType;
+                Documents.OperationType operationType 
+                    = (this.response == null || this.response?.OperationType == Documents.OperationType.Invalid) ? this.operationType : this.response.OperationType;
 
                 this.scope.AddAttribute(OpenTelemetryAttributeKeys.OperationType, operationType);
 

Microsoft.Azure.Cosmos/src/Telemetry/OpenTelemetry/OpenTelemetryResponse.cs

@@ -19,7 +19,7 @@ internal OpenTelemetryResponse(TransactionalBatchResponse responseMessage)
                   itemCount: responseMessage.Headers?.ItemCount,
                   requestMessage: null,
                   subStatusCode: (int)responseMessage.Headers?.SubStatusCode,
-                  activityId: string.Join(",", responseMessage.GetActivityIds()),
+                  activityId: responseMessage.Headers?.ActivityId,
                   correlationId: responseMessage.Headers?.CorrelatedActivityId)
         {
         }
@@ -35,7 +35,7 @@ internal OpenTelemetryResponse(ResponseMessage responseMessage)
                   subStatusCode: (int)responseMessage.Headers?.SubStatusCode,
                   activityId: responseMessage.Headers?.ActivityId,
                   correlationId: responseMessage.Headers?.CorrelatedActivityId,
-                  operationType: responseMessage is QueryResponse ? Documents.OperationType.Query.ToString() : null
+                  operationType: responseMessage is QueryResponse ? Documents.OperationType.Query : Documents.OperationType.Invalid
                  )
         {
         }
@@ -50,7 +50,7 @@ private OpenTelemetryResponse(
             int subStatusCode,
             string activityId,
             string correlationId,
-            string operationType = null)
+            Documents.OperationType operationType = Documents.OperationType.Invalid)
             : base(requestMessage)
         {
             this.StatusCode = statusCode;

Microsoft.Azure.Cosmos/src/Telemetry/OpenTelemetry/OpenTelemetryResponse{T}.cs

@@ -20,7 +20,7 @@ internal OpenTelemetryResponse(FeedResponse<T> responseMessage)
                subStatusCode: (int)responseMessage.Headers?.SubStatusCode,
                activityId: responseMessage.Headers?.ActivityId,
                correlatedActivityId: responseMessage.Headers?.CorrelatedActivityId,
-               operationType: responseMessage is QueryResponse<T> ? Documents.OperationType.Query.ToString() : null)
+               operationType: responseMessage is QueryResponse<T> ? Documents.OperationType.Query : Documents.OperationType.Invalid)
         {
         }
 
@@ -35,7 +35,7 @@ internal OpenTelemetryResponse(Response<T> responseMessage)
                   subStatusCode: (int)responseMessage.Headers?.SubStatusCode,
                   activityId: responseMessage.Headers?.ActivityId,
                   correlatedActivityId: responseMessage.Headers?.CorrelatedActivityId,
-                  operationType: responseMessage is QueryResponse ? Documents.OperationType.Query.ToString() : null)
+                  operationType: responseMessage is QueryResponse ? Documents.OperationType.Query : Documents.OperationType.Invalid)
         {
         }
 
@@ -49,7 +49,7 @@ private OpenTelemetryResponse(
            int subStatusCode,
            string activityId,
            string correlatedActivityId,
-           string operationType)
+           Documents.OperationType operationType)
            : base(requestMessage)
         {
             this.StatusCode = statusCode;

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Telemetry/DiagnosticsFilterHelperTest.cs

@@ -49,7 +49,7 @@ public void CheckReturnFalseOnSuccessAndLowerLatencyThanConfiguredConfig()
 
             Assert.IsFalse(
                 DiagnosticsFilterHelper
-                                .IsTracingNeeded(distributedTracingOptions, OperationType.Read.ToString(), response), 
+                                .IsTracingNeeded(distributedTracingOptions, OperationType.Read, response), 
                 $" Response time is {response.Diagnostics.GetClientElapsedTime().Milliseconds}ms " +
                 $"and Configured threshold value is {distributedTracingOptions.DiagnosticsLatencyThreshold.Value.Milliseconds}ms " +
                 $"and Is response Success : {response.StatusCode.IsSuccess()}" );
@@ -74,7 +74,7 @@ public void CheckReturnTrueOnFailedStatusCode()
 
             Assert.IsTrue(
                 DiagnosticsFilterHelper
-                    .IsTracingNeeded(distributedTracingOptions, OperationType.Read.ToString(), response),
+                    .IsTracingNeeded(distributedTracingOptions, OperationType.Read, response),
                 $" Response time is {response.Diagnostics.GetClientElapsedTime().Milliseconds}ms " +
                 $"and Configured threshold value is {distributedTracingOptions.DiagnosticsLatencyThreshold.Value.Milliseconds}ms " +
                 $"and Is response Success : {response.StatusCode.IsSuccess()}");