Question #1285
A company operates a global e-commerce platform on AWS, requiring low latency to ensure fast checkout processes. The application is deployed across multiple AWS Regions using Amazon EC2 instances in Auto Scaling groups behind Application Load Balancers (ALBs). The solutions architect must implement a solution to monitor application health and automatically redirect users to the nearest healthy Region.
Which solution meets these requirements?
Configure AWS Global Accelerator with a listener on the application's port, attaching Regional endpoints with the ALBs in each Region.
Set up an Amazon CloudFront distribution with the ALB as the origin, configuring cache behaviors based on origin headers and using Lambda@Edge for request routing.
Use Amazon Route 53 with latency-based routing policies and configure health checks for each ALB endpoint.
Implement an Amazon API Gateway with regional endpoints and configure canary deployments to shift traffic between Regions.
Explanation
The correct answer is A because AWS Global Accelerator is designed to improve availability and performance by routing traffic to the nearest healthy endpoint. Key points:
1. Low Latency: Global Accelerator uses AWS's global network infrastructure with anycast IPs, directing users to the nearest edge location, reducing latency.
2. Health Monitoring: It continuously monitors the health of Regional endpoints (ALBs) and automatically reroutes traffic if an endpoint becomes unhealthy.
3. Immediate Failover: Unlike DNS-based solutions (e.g., Route 53), Global Accelerator's anycast IPs enable near-instantaneous failover without DNS caching delays.
Why other options are incorrect:
- B: CloudFront focuses on caching and content delivery, not real-time routing based on health checks. Lambda@Edge adds complexity for routing.
- C: Route 53 uses DNS-based latency routing, which can suffer from TTL delays during failover, making it slower than Global Accelerator.
- D: API Gateway is for API management, not global traffic routing, and canary deployments are for gradual rollouts, not health-based redirection.
Key Takeaway: Use AWS Global Accelerator for low-latency, health-check-driven traffic routing across Regions with rapid failover.
Answer
The correct answer is: A