AWS Certified Solutions Architect – Professional — Question 904

A company is running a web application in the AWS Cloud. The application consists of dynamic content that is created on a set of Amazon EC2 instances. The
EC2 instances run in an Auto Scaling group that is configured as a target group for an Application Load Balancer (ALB).
The company is using an Amazon CloudFront distribution to distribute the application globally. The CloudFront distribution uses the ALB as an origin. The company uses Amazon Route 53 for DNS and has created an A record of www.example.com for the CloudFront distribution.
A solutions architect must configure the application so that itis highly available and fault tolerant.
Which solution meets these requirements?

Answer options

• A. Provision a full, secondary application deployment in a different AWS Region. Update the Route 53 A record to be a failover record. Add both of the CloudFront distributions as values. Create Route 53 health checks.
• B. Provision an ALB, an Auto Scaling group, and EC2 instances in a different AWS Region. Update the CloudFront distribution, and create a second origin for the new ALB. Create an origin group for the two origins. Configure one origin as primary and one origin as secondary.
• C. Provision an Auto Scaling group and EC2 instances in a different AWS Region. Create a second target for the new Auto Scaling group in the ALB. Set up the failover routing algorithm on the ALB.
• D. Provision a full, secondary application deployment in a different AWS Region. Create a second CloudFront distribution, and add the new application setup as an origin. Create an AWS Global Accelerator accelerator. Add both of the CloudFront distributions as endpoints.

Correct answer: B

Explanation

Option B is correct because Amazon CloudFront origin groups enable origin failover, which automatically diverts traffic to a secondary origin in another AWS Region if the primary origin is unhealthy. Option A is incorrect because Route 53 cannot easily perform active-passive failover between two CloudFront distributions in this manner. Option C is incorrect because an ALB is a regional resource and cannot load balance across multiple AWS Regions, and Option D is incorrect because AWS Global Accelerator does not support CloudFront distributions as backend endpoints.