AWS Certified Advanced Networking – Specialty (ANS-C01)Network DesignMedium
An e-commerce company operates a highly available web application across multiple AWS Regions. They need to implement a disaster recovery (DR) strategy where if the primary Region becomes unavailable, traffic automatically fails over to a secondary Region with minimal downtime. The solution must use DNS-based failover.
- ARoute 53 Simple Routing Policy with manual DNS updates.
- BElastic Load Balancer (ELB) with cross-zone load balancing.
- CRoute 53 Failover Routing Policy with health checks.
- DAWS Global Accelerator with endpoint groups in each Region.
Show answer & explanationAnswer & explanation
Correct answer: C. Route 53 Failover Routing Policy with health checks.
Route 53 Failover Routing Policy combined with Route 53 health checks automatically detects unhealthy primary endpoints and reroutes traffic to healthy secondary endpoints. This provides DNS-based automatic failover for disaster recovery with minimal intervention.
Why the other options are wrong
- A. Simple routing does not provide health checks or automatic failover; manual updates would be required, leading to significant downtime.
- B. ELB with cross-zone load balancing operates within a single Region and does not provide multi-Region disaster recovery.
- D. AWS Global Accelerator provides performance optimization and failover but is not purely a DNS-based failover mechanism; it uses static Anycast IPs and the AWS global network.
Route 53 Failover Routing
A Route 53 routing policy that routes traffic to a resource if it's healthy, or to a different resource if the first is unhealthy.
- Requires Route 53 health checks to monitor endpoint health.
- Supports active-passive (primary/secondary) failover.
- Provides automatic DNS updates for disaster recovery.
Memory trick: Route 53 detects failure and switches traffic over, like a reliable DNS traffic cop.