How to Configure Azure Front Door for Multi-Region Failover
Azure Front Door is a global load balancer and application accelerator. You put it in front of your app so traffic is routed to healthy backends and, when one region fails, traffic fails over to another without waiting for DNS or manual intervention.
Why use Front Door for failover
Regional load balancers only see traffic that has already reached that region. If the region is down, the load balancer is down too.
Front Door runs at the edge. The client connects to a point of presence (PoP) close to them; Front Door then forwards the request to the best available backend based on health and routing rules. When your primary region goes unhealthy (outage, failed health probe, or maintenance), Front Door stops sending traffic there and sends it to the next healthy origin group. Failover is in the order of seconds, not minutes or hours, and you do not depend on DNS TTL or manual flip.
Steps in brief
Create a Front Door (Standard or Premium) profile in the Azure Portal or via ARM/Bicep/Terraform. Add two or more origin groups, each in a different region, and point each origin to your application backend (App Service, AKS, VM scale set, or static site). Configure a health probe that hits a path your app serves (for example /health). Create a route that associates your domain or default hostname with the primary origin group and set the secondary group as failover. Front Door will probe the primary; after consecutive failures it marks the origin unhealthy and sends new requests to the secondary. Attach your custom domain and a TLS certificate so production traffic is encrypted. Validate by temporarily failing the primary health endpoint or taking the primary region offline and confirming traffic shifts to the secondary.
Take the next step
This guide summarizes how to configure Azure Front Door for multi-region failover. For the bigger picture on handling traffic spikes and protecting the origin, see our perspective on surviving the thundering herd. Reach out to discuss your architecture.