The requirement is to deploy a stateless application with multi-Region fault tolerance, ensuring high availability even if an entire AWS Region becomes unavailable. For this design, traffic must be actively served from both Regions, not only during a failure event.
Option C correctly implements an active-active, multi-Region architecture. By deploying the application to both EKS clusters, each Region is capable of serving traffic independently. Using Amazon Route 53 weighted routing, traffic is distributed across both Application Load Balancers, allowing both Regions to handle requests simultaneously. If one Region becomes unhealthy, Route 53 health checks can stop routing traffic to that Region, maintaining availability.
Implementing Kubernetes readiness and liveness probes ensures that traffic is only sent to healthy pods within each cluster. This provides fault tolerance at both the container level (pod health) and the Regional level (Route 53 routing).
Option A uses a failover routing policy, which results in an active-passive design. While fault tolerant, it does not utilize both Regions simultaneously and provides slower recovery during Region failure. Options B and D deploy the application only in the primary Region, which does not meet multi-Region fault tolerance requirements.
Therefore, Option C delivers the most resilient, highly available, and AWS-recommended architecture for a stateless, multi-Region EKS application.
