How to achieve redundancy in app service?

Question

i need to setup app service with redundancy. I have application gateway behind that i need to setup 3 web app with redundancy please explain steps to achieve this.

Answer 1

Welcome to Microsoft Q&A! Thanks for posting a good question.

If you have provisioned the WebApps in 3 different regions, which would further enhance redundancy.
A multi-region architecture can provide higher availability than deploying to a single region.

Based on your requirement, if it’s 3 WebApps in 3 regions, you could have Application Gateway and Traffic Manager, or you could also leverage Azure Front Door service.

It is recommended that all websites be geographically redundant and deliver traffic to its users from the closest (lowest latency) location to them whenever possible. Combining services from Traffic Manager, Front Door, Application Gateway, and Load Balancer enables you to build geographically and zonally redundant to maximize reliability, scale, and performance.

Just to highlight more on this, Azure App service web apps is multi-tenant in nature and rely on a specific host header or SNI extension to resolve to the correct endpoint. The Application Gateway v2 SKU automatically ensures that new instances are spread across fault domains and update domains. If you choose zone redundancy, the newest instances are also spread across availability zones to offer zonal failure resiliency.

A multi-region architecture can provide higher availability than deploying to a single region. If a regional outage affects the primary region, you can use Front Door to fail over to the secondary region. This architecture can also help if an individual subsystem of the application fails.

You may use Azure Traffic Manager to route traffic to all available redundancies. However, note that you can only specify one App Service endpoint per region in a Traffic Manager profile).

Answer 2

Not much detail on what you have and what you want. There are many ways to accomplish this. You can use IIS (IIS experts can be found at iis.net/forums). You can configure Network Load Balancing (https://learn.microsoft.com/en-us/windows-server/networking/technologies/network-load-balancing and https://support.microsoft.com/en-us/help/4494444/configuring-network-infrastructure-to-support-the-nlb-operation-mode).

What is the application service? Does it have its own capability for redundancy (some applications build it in)?