Question

A financial services company runs a customer-facing REST API on an Application Load Balancer backed by Auto Scaling groups in us-east-1. Regulatory requirements mandate the API remain available even if an entire AWS Region becomes unreachable, with an RTO of under 5 minutes and no manual intervention. The team has already deployed an identical stack in us-west-2 that stays warm and healthy. They need to route all traffic to the primary Region under normal conditions and automatically shift 100% of traffic to the secondary Region only when the primary API is unhealthy. Which solution meets these requirements MOST effectively?

Accepted Answer

Configure Amazon Route 53 failover routing with a primary and secondary alias record, attaching a Route 53 health check that monitors the primary ALB endpoint so DNS resolves to us-west-2 when the primary check fails.

Answer

Use Amazon Route 53 weighted routing with 100% weight on us-east-1 and 0% on us-west-2, and update the weights manually through automation when the primary Region fails.

Answer

Place both ALBs behind Amazon CloudFront with two origins and configure origin failover using an origin group, relying on 5xx error responses to trigger the failover.

Answer

Configure Amazon Route 53 latency-based routing across both Regions so clients are automatically directed to the lowest-latency healthy endpoint.