Question

A retail company runs a stateless web API on 12 on-premises Windows servers behind a hardware load balancer. They are migrating to Azure and want a phased cutover: some traffic served on-premises and some in Azure during a validation window, with the ability to shift the weighting gradually and roll back quickly if error rates rise. On-premises and Azure are connected via ExpressRoute. Which approach best supports a controlled, weighted migration cutover with fast rollback?

Accepted Answer

Place Azure Front Door in front of both the on-premises endpoint and the Azure App Service, and use weighted routing to gradually shift traffic while monitoring health probes.

Answer

Use Azure Migrate to replicate the servers, then perform a single big-bang DNS cutover to the Azure Load Balancer once replication completes.

Answer

Deploy an internal Azure Load Balancer in the hub VNet and rely on ExpressRoute to distribute requests across both environments automatically.

Answer

Configure Azure Traffic Manager with priority routing so all traffic goes to on-premises until the Azure endpoint becomes the primary.