AWS Certified Solutions Architect – Associate (SAA-C03) — Question 795

A company serves its website by using an Auto Scaling group of Amazon EC2 instances in a single AWS Region. The website does not require a database.

The company is expanding, and the company's engineering team deploys the website to a second Region. The company wants to distribute traffic across both Regions to accommodate growth and for disaster recovery purposes. The solution should not serve traffic from a Region in which the website is unhealthy.

Which policy or resource should the company use to meet these requirements?

Answer options

• A. An Amazon Route 53 simple routing policy
• B. An Amazon Route 53 multivalue answer routing policy
• C. An Application Load Balancer in one Region with a target group that specifies the EC2 instance IDs from both Regions
• D. An Application Load Balancer in one Region with a target group that specifies the IP addresses of the EC2 instances from both Regions

Correct answer: B

Explanation

Amazon Route 53 multivalue answer routing allows traffic to be distributed across multiple resources while performing Route 53 health checks to ensure traffic is only routed to healthy endpoints. Simple routing does not support health checking of multiple endpoints in this manner. Using an Application Load Balancer in a single Region fails to meet the disaster recovery and high-availability requirements because the ALB itself represents a single point of failure for both Regions.