Merge pull request #293163 from Turupu-Sameera/main

Add Relay RPError Documentation in Pool Errors

Author: prmerger-automator[bot]

articles/batch/batch-pool-node-error-checking.md

@@ -1,7 +1,7 @@
 ---
 title: Pool and node errors
 description: Learn about background operations, errors to check for, and how to avoid errors when you create Azure Batch pools and nodes.
-ms.date: 06/27/2024
+ms.date: 01/22/2025
 ms.topic: how-to
 ---
 
@@ -13,7 +13,54 @@ Make sure to set your applications to implement comprehensive error checking, es
 
 ## Pool errors
 
-Pool errors might be related to resize timeout or failure, automatic scaling failure, or pool deletion failure.
+Pool errors might be related to resize timeout or failure, automatic scaling failure, or pool deletion failure. With the inclusion of more detailed error messages, diagnosing and resolving these issues has become more straightforward.
+
+### Relay Provider Error Details
+Relay provider errors are directly relayed from the underlying Azure resource providers, such as the Azure Virtual Machine Scale Set (VMSS), and they offer deeper insights into why a pool operation failed. These errors typically occur when a pool's creation, resizing, or deletion is impacted by a lower-layer service issue.
+
+#### Structure of Relay Provider Error
+These errors are provided in a structured JSON format containing the following key components:
+
+- **Error Code**: The type of error encountered (e.g., AllocationFailed, BadRequest, etc.).
+- **Error Message**: Brief description of the error 
+- **Provider Error Json**: A detailed error message generated by the underlying Azure service (e.g., VMSS).
+- **Provider Error Truncated**: A Boolean indicating whether the provider error message has been truncated due to size limits.
+
+#### Example Relay Provider Errors
+
+##### Example 1
+**Error Code**: `AllocationFailed`  
+**Error Message**: Desired number of dedicated nodes could not be allocated  
+**Provider Error JSON**:
+```json
+{
+  "error": {
+    "code": "BadRequest",
+    "message": "The selected VM size 'STANDARD_A1_V2' cannot boot Hypervisor Generation '2'. If this was a Create operation, please ensure that the Hypervisor Generation of the Image matches the Hypervisor Generation of the selected VM Size. If this was an Update operation, please choose a Hypervisor Generation '2' VM Size."
+  }
+}
+```
+**Provider Error JSON Truncated**: False
+
+This error indicates a mismatch between the VM size and the Hypervisor generation. The error message suggests selecting a compatible VM size to resolve the issue.
+
+##### Example 2
+**Error Code**: `AllocationFailed`  
+**Error Message**: An internal error was occurred while resizing the pool  
+**Provider Error JSON**:
+```json
+{
+  "error": {
+    "code": "ScopeLocked",
+    "message": "The scope '/subscriptions/<subscription-id>/resourceGroups/<resource-group-name>/providers/Microsoft.Compute/VirtualMachineScaleSets/<guid>-azurebatch-VMSS-D' cannot perform write operation because the following scope(s) are locked: '/subscriptions/<subscription-id>/resourceGroups/<resource-group-name>/providers/Microsoft.Compute/VirtualMachineScaleSets/<guid>-azurebatch-VMSS-D'. Please remove the lock and try again."
+  }
+}
+```
+**Provider Error JSON Truncated**: False
+
+This error indicates that the pool resize operation failed because a scope was locked, preventing the write operation; removing the lock can resolve the issue.
+
+Relay provider errors offer deeper insights into pool operation failures, making it easier to diagnose and resolve issues directly from the Azure services.
 
 ### Resize timeout or failure