Amazon Route 53 health checks can automatically perform DNS failover to healthy endpoints. When integrated with an Application Load Balancer, this provides a highly resilient system architecture that automatically routes traffic to healthy resources across Regions or endpoints.
From AWS Documentation:
“Route 53 DNS failover automatically routes traffic away from unhealthy resources and directs it to healthy resources that you specify in DNS records.”
(Source: Amazon Route 53 Developer Guide – DNS Failover)
Why B is correct:
Route 53 health checks automatically monitor endpoint health and switch to a healthy target when the primary endpoint fails.
The failover process is automatic, with no manual updates to DNS records required.
Combined with ALB’s built-in multi-AZ resilience, this provides maximum availability.
Why others are incorrect:
A & C: Require manual DNS updates, which are not automatic and introduce latency.
D: Creating new ALBs during failover increases downtime and is operationally inefficient.
[References:, Amazon Route 53 Developer Guide – “Configuring DNS Failover”, AWS Well-Architected Framework – Reliability Pillar, , , ]
