Code changes to address some of the review comments.

Microsoft.Azure.Cosmos/src/ResourceThrottleRetryPolicy.cs

@@ -164,7 +164,7 @@ private object GetExceptionMessage(Exception exception)
         public void OnBeforeSendRequest(DocumentServiceRequest request)
         {
             this.isMultiMasterWriteRegion = !request.IsReadOnlyRequest
-                && (this.globalEndpointManager?.CanUseMultipleWriteLocations(request) ?? false);
+                && (this.globalEndpointManager?.CanSupportMultipleWriteLocations(request) ?? false);
         }
 
         /// <summary>

Microsoft.Azure.Cosmos/src/Routing/GlobalEndpointManager.cs

@@ -534,6 +534,18 @@ public virtual async Task RefreshLocationAsync(bool forceRefresh = false)
 
             await this.RefreshDatabaseAccountInternalAsync(forceRefresh: forceRefresh);
         }
+
+        /// <summary>
+        /// Determines whether the current configuration and state of the service allow for supporting multiple write locations.
+        /// This method returns True is the AvailableWriteLocations in LocationCache is more than 1. Otherwise, it returns False.
+        /// </summary>
+        /// <param name="request">The document service request for which the write location support is being evaluated.</param>
+        /// <returns>A boolean flag indicating if the available write locations are more than one.</returns>
+        public bool CanSupportMultipleWriteLocations(DocumentServiceRequest request)
+        {
+            return this.CanUseMultipleWriteLocations(request)
+                && this.locationCache.GetAvailableWriteLocations()?.Count > 1;
+        }
 
 #pragma warning disable VSTHRD100 // Avoid async void methods
         private async void StartLocationBackgroundRefreshLoop()

Microsoft.Azure.Cosmos/src/Routing/IGlobalEndpointManager.cs

@@ -36,5 +36,7 @@ internal interface IGlobalEndpointManager : IDisposable
         ReadOnlyDictionary<string, Uri> GetAvailableWriteEndpointsByLocation();
 
         ReadOnlyDictionary<string, Uri> GetAvailableReadEndpointsByLocation();
+
+        bool CanSupportMultipleWriteLocations(DocumentServiceRequest request);
     }
 }

Microsoft.Azure.Cosmos/src/Routing/LocationCache.cs

@@ -263,6 +263,11 @@ public ReadOnlyCollection<string> GetAvailableReadLocations()
         {
             return this.locationInfo.AvailableReadLocations;
         }
+
+        public ReadOnlyCollection<string> GetAvailableWriteLocations()
+        {
+            return this.locationInfo.AvailableWriteLocations;
+        }
 
         /// <summary>
         /// Resolves request to service endpoint. 
@@ -530,7 +535,6 @@ public bool ShouldRefreshEndpoints(out bool canRefreshInBackground)
         public bool CanUseMultipleWriteLocations(DocumentServiceRequest request)
         {
             return this.CanUseMultipleWriteLocations()
-                && this.locationInfo.AvailableWriteLocations.Count > 1
                 && (request.ResourceType == ResourceType.Document ||
                 (request.ResourceType == ResourceType.StoredProcedure && request.OperationType == Documents.OperationType.ExecuteJavaScript));
         }