Batch API: Adds Session token support (#1870)

* Session token support for transactional batch

Signed-off-by: Rakesh Kumar <rakkuma@microsoft.com>

* Contract change

Signed-off-by: Rakesh Kumar <rakkuma@microsoft.com>

* code review fix

Signed-off-by: Rakesh Kumar <rakkuma@microsoft.com>

* Session token error message less strict check

Signed-off-by: Rakesh Kumar <rakkuma@microsoft.com>

* Change

Signed-off-by: Rakesh Kumar <rakkuma@microsoft.com>

* Adding session consistency

Signed-off-by: Rakesh Kumar <rakkuma@microsoft.com>

Co-authored-by: Matias Quaranta <ealsur@users.noreply.github.com>

Microsoft.Azure.Cosmos/src/Batch/TransactionalBatchRequestOptions.cs

@@ -9,6 +9,39 @@ namespace Microsoft.Azure.Cosmos
     /// </summary>
     public class TransactionalBatchRequestOptions : RequestOptions
     {
+        /// <summary>
+        /// Gets or sets the token for use with session consistency in the Azure Cosmos DB service.
+        /// </summary>
+        /// <value>
+        /// The token for use with session consistency.
+        /// </value>
+        ///
+        /// <remarks>
+        /// One of the <see cref="ConsistencyLevel"/> for Azure Cosmos DB is Session. In fact, this is the default level applied to accounts.
+        /// <para>
+        /// When working with Session consistency, each batch request with write operation to Azure Cosmos DB is assigned a new SessionToken.
+        /// The CosmosClient will use this token internally with each read/query/batch request to ensure that the set
+        /// consistency level is maintained.
+        ///
+        /// <para>
+        /// In some scenarios you need to manage this Session yourself;
+        /// Consider a web application with multiple nodes, each node will have its own instance of <see cref="CosmosClient"/>
+        /// If you wanted these nodes to participate in the same session (to be able read your own writes consistently across web tiers)
+        /// you would have to send the SessionToken from <see cref="TransactionalBatchResponse"/> of the write action on one node
+        /// to the client tier, using a cookie or some other mechanism, and have that token flow back to the web tier for subsequent reads.
+        /// If you are using a round-robin load balancer which does not maintain session affinity between requests, such as the Azure Load Balancer,
+        /// the read could potentially land on a different node to the write request, where the session was created.
+        /// </para>
+        ///
+        /// <para>
+        /// If you do not flow the Azure Cosmos DB SessionToken across as described above you could end up with inconsistent read results for a period of time.
+        /// </para>
+        ///
+        /// </para>
+        /// <see href="https://docs.microsoft.com/azure/cosmos-db/consistency-levels" />
+        /// </remarks>
+        public string SessionToken { get; set; }
+
         /// <summary>
         /// Gets or sets the consistency level required for the request in the Azure Cosmos DB service.
         /// </summary>
@@ -34,6 +67,8 @@ public ConsistencyLevel? ConsistencyLevel
         /// <param name="request">The <see cref="RequestMessage"/></param>
         internal override void PopulateRequestOptions(RequestMessage request)
         {
+            RequestOptions.SetSessionToken(request, this.SessionToken);
+
             base.PopulateRequestOptions(request);
         }
     }

Microsoft.Azure.Cosmos/src/Batch/TransactionalBatchResponse.cs

@@ -363,7 +363,7 @@ private static async Task<TransactionalBatchResponse> PopulateFromContentAsync(
             {
                 foreach (TransactionalBatchOperationResult result in results)
                 {
-                    if ((int)result.StatusCode != (int)StatusCodes.FailedDependency)
+                    if ((int)result.StatusCode != (int)StatusCodes.FailedDependency && (int)result.StatusCode >= (int)StatusCodes.StartingErrorCode)
                     {
                         responseStatusCode = result.StatusCode;
                         responseSubStatusCode = result.SubStatusCode;