Azure Front Door does not load balance using VM IPs for origin

Question

I am new to Azure cloud and I am trying to deploy Azure Front Door to divert traffic between two VMs (also in Azure. It uses docker Nginx managed from IoT Hub).

I have created an endpoint, which then uses a route with an origin group. In the origin group, I have added two VMs using their public IP address (I also tried with a custom domain name). When I enable Ngingx on both the VMs azure front door works fine, if I stop the Nginx on priority 1 origin, I see an error:

Our services aren't available right now We're working to restore all services as soon as possible. Please check back soon.

I would have expected it to use the other origin automatically if one origin fails. However, if I manually disable one origin, then it does send the request to the other origin.

Answer 1

When using Azure Front Door for load balancing between two VMs, it should automatically route traffic to the second VM if the first one fails

but you need to be careful for the following condiguration

• Azure Front Door configuration > Origin Group > Health Probes.
• Check: Protocol: Does the protocol (HTTP or HTTPS) align with your Nginx setup on the VMs? Interval: Is the interval frequent enough to detect failures quickly?

then

• Azure Front Door configuration > Backend Pools
• Check that the VMs and their health probe status is "Healthy."
• Ensure Priority and Weight settings are configured correctly