Merge branch 'main' of https://github.com/MicrosoftDocs/azure-docs-pr into httpkeepalive

Author: duongau

articles/batch/simplified-compute-node-communication.md

@@ -2,7 +2,7 @@
 title: Use simplified compute node communication
 description: Learn about the simplified compute node communication mode in the Azure Batch service and how to enable it.
 ms.topic: how-to
-ms.date: 11/17/2022
+ms.date: 03/29/2023
 ms.custom: references_regions
 ---
 
@@ -11,8 +11,8 @@ ms.custom: references_regions
 An Azure Batch pool contains one or more compute nodes that execute user-specified workloads in the form of Batch tasks. To enable Batch functionality and Batch pool infrastructure management, compute nodes must communicate with the Azure Batch service.
 
 Batch supports two types of node communication modes:
-- `Classic` where the Batch service initiates communication to the compute nodes
-- `Simplified` where the compute nodes initiate communication to the Batch service
+- Classic: where the Batch service initiates communication to the compute nodes
+- Simplified: where the compute nodes initiate communication to the Batch service
 
 This document describes the simplified compute node communication mode and the associated network configuration requirements.
 
@@ -21,6 +21,12 @@ This document describes the simplified compute node communication mode and the a
 > Batch pools with [no public IP addresses](simplified-node-communication-pool-no-public-ip.md) using the
 > node management private endpoint without Internet outbound access.
 
+> [!WARNING]
+> The classic compute node communication model will be retired on **31 March 2026** and will be replaced with
+> the simplified compute node communication model as described in this document. For more information, see the
+> classic compute node communication mode
+> [migration guide](batch-pools-to-simplified-compute-node-communication-model-migration-guide.md).
+
 ## Supported regions
 
 Simplified compute node communication in Azure Batch is currently available for the following regions:
@@ -31,7 +37,7 @@ Simplified compute node communication in Azure Batch is currently available for
 
 - China: all China regions where Batch is present except for China North 1 and China East 1.
 
-## Compute node communication differences between Classic and Simplified
+## Compute node communication differences between classic and simplified modes
 
 The simplified compute node communication mode streamlines the way Batch pool infrastructure is
 managed on behalf of users. This communication mode reduces the complexity and scope of inbound
@@ -59,7 +65,7 @@ NSGs, UDRs, and firewalls:
 
 Outbound requirements for a Batch account can be discovered using the
 [List Outbound Network Dependencies Endpoints API](/rest/api/batchmanagement/batch-account/list-outbound-network-dependencies-endpoints)
-This API will report the base set of dependencies, depending upon the Batch account pool communication mode.
+This API reports the base set of dependencies, depending upon the Batch account pool communication mode.
 User-specific workloads may need extra rules such as opening traffic to other Azure resources (such as Azure
 Storage for Application Packages, Azure Container Registry, etc.) or endpoints like the Microsoft package
 repository for virtual file system mounting functionality.
@@ -78,14 +84,13 @@ example, you can scope your outbound communication rules to Azure Storage to ena
 storage accounts or other storage accounts for resource files or output files.
 
 Even if your workloads aren't currently impacted by the changes (as described in the next section), it's
-recommended to move to the `simplified` mode. Doing so will ensure your Batch workloads are ready for any
-future improvements enabled by this mode, and also for when this communication mode will move to become
-the default.
+recommended to move to the `simplified` mode. Future improvements in the Batch service may only be functional
+with simplified compute node communication.
 
 ## Potential impact between classic and simplified communication modes
 
-In many cases, the `simplified` communication mode won't directly affect your Batch workloads. However,
-simplified compute node communication will have an impact for the following cases:
+In many cases, the `simplified` communication mode doesn't directly affect your Batch workloads. However,
+simplified compute node communication has an impact for the following cases:
 
 - Users who specify a Virtual Network as part of creating a Batch pool and do one or both of the following actions:
    - Explicitly disable outbound network traffic rules that are incompatible with simplified compute node communication.
@@ -106,7 +111,7 @@ The following set of steps is required to migrate to the new communication mode:
    - Outbound:
      - Destination port 443 over TCP to Storage.*region*
      - Destination port 443 over ANY to BatchNodeManagement.*region*
-1. If you have any other inbound or outbound scenarios required by your workflow, you'll need to ensure that your rules reflect these requirements.
+1. If you have any other inbound or outbound scenarios required by your workflow, you need to ensure that your rules reflect these requirements.
 1. Use one of the following options to update your workloads to use the new communication mode.
    - Create new pools with the `targetNodeCommunicationMode` set to `simplified` and validate that the new pools are working correctly. Migrate your workload to the new pools and delete any earlier pools.
    - Update existing pools `targetNodeCommunicationMode` property to `simplified` and then resize all existing pools to zero nodes and scale back out.
@@ -117,22 +122,34 @@ The following set of steps is required to migrate to the new communication mode:
    - Outbound:
      - Destination port 443 over ANY to BatchNodeManagement.*region*
 
-If you follow these steps, but later want to switch back to `classic` compute node communication, you'll need to take the following actions:
+If you follow these steps, but later want to switch back to `classic` compute node communication, you need to take the following actions:
 
+1. Revert any networking configuration operating exclusively in `simplified` compute node communication mode.
 1. Create new pools or update existing pools `targetNodeCommunicationMode` property set to `classic`.
 1. Migrate your workload to these pools, or resize existing pools and scale back out (see step 3 above).
 1. See step 4 above to confirm that your pools are operating in `classic` communication mode.
-1. Optionally revert your networking configuration.
+1. Optionally restore your networking configuration.
 
 ## Specifying the node communication mode on a Batch pool
 
-Below are examples of how to create a Batch pool with `simplified` compute node communication.
+The [`targetNodeCommunicationMode`](/rest/api/batchservice/pool/add) property on Batch pools allows you to indicate a preference
+to the Batch service for which communication mode to utilize between the Batch service and compute nodes. The following are
+the allowable options on this property:
+
+- `classic`: create the pool using classic compute node communication.
+- `simplified`: create the pool using simplified compute node communication.
+- `default`: allow the Batch service to select the appropriate compute node communication mode. For pools without a virtual
+network, the pool may be created in either `classic` or `simplified` mode. For pools with a virtual network, the pool will always
+default to `classic` until **30 September 2024**. For more information, see the classic compute node communication mode
+[migration guide](batch-pools-to-simplified-compute-node-communication-model-migration-guide.md).
 
 > [!TIP]
 > Specifying the target node communication mode is a preference indication for the Batch service and not a guarantee that it
 > will be honored. Certain configurations on the pool may prevent the Batch service from honoring the specified target node
 > communication mode, such as interaction with No public IP address, virtual networks, and the pool configuration type.
 
+The following are examples of how to create a Batch pool with `simplified` compute node communication.
+
 ### Azure portal
 
 Navigate to the Pools blade of your Batch account and click the Add button. Under `OPTIONAL SETTINGS`, you can
@@ -141,9 +158,9 @@ select `Simplified` as an option from the pull-down of `Node communication mode`
    :::image type="content" source="media/simplified-compute-node-communication/add-pool-simplified-mode.png" alt-text="Screenshot that shows creating a pool with simplified mode.":::
 
 To update an existing pool to simplified communication mode, navigate to the Pools blade of your Batch account and
-click on the pool to update. On the left-side navigation, select `Node communication mode`. There you'll be able
+click on the pool to update. On the left-side navigation, select `Node communication mode`. There you're able
 to select a new target node communication mode as shown below. After selecting the appropriate communication mode,
-click the `Save` button to update. You'll need to scale the pool down to zero nodes first, and then back out
+click the `Save` button to update. You need to scale the pool down to zero nodes first, and then back out
 for the change to take effect, if conditions allow.
 
    :::image type="content" source="media/simplified-compute-node-communication/update-pool-simplified-mode.png" alt-text="Screenshot that shows updating a pool to simplified mode.":::
@@ -202,7 +219,7 @@ if specified on the pool. For more information, see the
 [migration guide](batch-pools-without-public-ip-addresses-classic-retirement-migration-guide.md).
 - Cloud Service Configuration pools are currently not supported for simplified compute node communication and are
 [deprecated](https://azure.microsoft.com/updates/azure-batch-cloudserviceconfiguration-pools-will-be-retired-on-29-february-2024/).
-Specifying a communication mode for these types of pools aren't honored and will always result in `classic`
+Specifying a communication mode for these types of pools aren't honored and always results in `classic`
 communication mode. We recommend using Virtual Machine Configuration for your Batch pools. For more information, see
 [Migrate Batch pool configuration from Cloud Services to Virtual Machine](batch-pool-cloud-service-to-virtual-machine-configuration.md).