D. the Application Health extension -- is correct

Application Health Extension

D: For the use of VM Scale Set, using load balance via code within your build of a web app in Azure DevOps for example, the “Application Health extension” is used, which will play the role similar to a Load Balancer Health probe within the portal. This extension used in your code checks the response of a Vm Scale Set sizing instance. When one of the instances to be scheduled does not respond through the configured TCP port, it will have the status of Unhealthy. If you need an autoscale and it doesn't respond, this extension can perform automatic repairs for that instance. Example JSON code from a REST API. It also runs on Azure PowerShell and Azure CLI 2.0.

D. the Application Health extension When to use the Application Health extension The Application Health Extension is deployed inside a Virtual Machine Scale Set instance and reports on application health from inside the scale set instance. The extension probes on a local application endpoint and will update the health status based on TCP/HTTP(S) responses received from the application. This health status is used by Azure to initiate repairs on unhealthy instances and to determine if an instance is eligible for upgrade operations. The extension reports health from within a VM and can be used in situations where an external probe such as the Azure Load Balancer health probes can’t be used. https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-health-extension?tabs=rest-api

D. https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-health-extension?tabs=rest-api#when-to-use-the-application-health-extension

D is correct as supported by given explanation

D. The application health extension

https://docs.microsoft.com/en-us/azure/load-balancer/load-balancer-custom-probe-overview Inside Limitations section you find the right answer.

Vote D

correct

Got this January 2022

Application Health extension

Why answer 'A' is not correct? I recently used an existing Load Balancer Health Probe, an external health probe in contrast to an internal health probe like Application Health extension, to provide health checks required for 'rolling' upgrade policy and 'automatic instance repairs'. https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-health-extension#when-to-use-the-application-health-extension

D is the correct answer.

correct Ans