Merge pull request #266578 from tfitzmac/0216throttle

added concurrent operation resolution

Author: v-dirichards

articles/azure-resource-manager/management/frequently-asked-questions.yml

@@ -3,7 +3,7 @@ metadata:
   title: Azure Resource Manager frequently asked questions
   description: Answers to common questions about using Azure Resource Manager to manage resources.
   ms.topic: faq
-  ms.date: 01/12/2024
+  ms.date: 02/16/2024
   content_well_notification: 
     - AI-contribution
 
@@ -40,6 +40,12 @@ sections:
           subscription. Settings such as tags, role assignments, and policies aren't automatically transferred from the original resource group to the destination resource group. 
           You need to reapply these settings to the new resource group. For more information, see [Move resources to new resource group or subscription](./move-support-resources.md).
 
+  - name: Resources
+    questions:
+      - question: What happens if two operations update the same resource at the same time?
+        answer: |
+          Azure Resource Manager detects the conflict and permits only one operation to complete successfully. The other operation fails and returns a 409 conflict error.
+          If the blocked operation has the correct state, you can retry the operation.``
 
 additionalContent: |
     ## Related content

articles/azure-resource-manager/management/overview.md

@@ -2,7 +2,7 @@
 title: Azure Resource Manager overview
 description: Describes how to use Azure Resource Manager for deployment, management, and access control of resources on Azure.
 ms.topic: overview
-ms.date: 02/14/2024
+ms.date: 02/16/2024
 ms.custom: devx-track-arm-template
 ---
 # What is Azure Resource Manager?
@@ -136,6 +136,14 @@ The resource group location is where Azure Resource Manager stores metadata for
 
 When the resource group's region is unavailable, Azure Resource Manager is unable to update your resource's metadata and blocks your write calls. By colocating your resource and resource group region, you reduce the risk of region unavailability because your resources and metadata exist in one region instead of multiple regions.
 
+## Resolve concurrent operations
+
+When two or more operations try to update the same resource at the same time, Azure Resource Manager detects the conflict and permits only one operation to complete successfully. Azure Resource Manager blocks the other operations and returns an error.
+
+Concurrent resource updates can cause unexpected results. This resolution ensures that your updates are deterministic and reliable. You know the status of your resources and avoid any inconsistency or data loss.  
+
+Suppose you have two requests (A and B) that try to update the same resource at the same time. If request A finishes before request B, request A succeeds and request B fails. Request B returns the 409 error. After getting that error code, you can get the updated status of the resource and determine if you want to resend request B.
+
 ## Next steps
 
 * To learn about limits that are applied across Azure services, see [Azure subscription and service limits, quotas, and constraints](azure-subscription-service-limits.md).