How to achieve High Availability for multiple App Services in Azure

1
votes

I have 2 same Web App and I have added them to application gateway's backed pool in Azure. I have one domain for the application Gateway and I can bind only one web app to it. Is there any way to add 2 Web App with the same domain of application gateway?

If not, then any other way to achieve high availability for Web Apps?

I want that if one Web App is not reachable, the traffic should go to other Web App. The Web Apps are not stateless and therefore ruled out the use of Traffic Manager Profile due to lack of Session Persistence.

I have gone through various questions mentioned below on the same topic, but none is related or have satisfactory solution. - DNS: High Availability with Azure Web Apps + Traffic Manager - Achieving High Availability using Azure Traffic Manager - Is it possible that one domain name has multiple corresponding IP addresses?

1
azureazure-web-app-servicehigh-availabilityazure-application-gateway
You can use Azure Front Door. it should be ok for you as you can have sticky session enable – Thomas

1 Answers

0
votes

For App Service, Application Gateway cannot be used for Load balancing Purpose. You can use Application Gateway as WAF. In your scenario, as Thomas stated, AFD would be the best option.

You can leverage the priority option which can be configured while adding App Service to the backend pool to achieve your ask.

You can assign priorities to your different backends when you want to use a primary service backend for all traffic, and provide backups in case the primary or the backup backends are unavailable.

In this case, when the probe to the Primary goes down, then the traffic will be routed to the secondary Web App.

Reference: https://docs.microsoft.com/en-in/azure/frontdoor/front-door-routing-methods