AWS Certified Solutions Architect – Professional — Question 280

A North American company with headquarters on the East Coast is deploying a new web application running on Amazon EC2 in the us-east-1 Region. The application should dynamically scale to meet user demand and maintain resiliency. Additionally, the application must have disaster recover capabilities in an active-passive configuration with the us-west-1 Region.
Which steps should a solutions architect take after creating a VPC in the us-east-1 Region?

Answer options

• A. Create a VPC in the us-west-1 Region. Use inter-Region VPC peering to connect both VPCs. Deploy an Application Load Balancer (ALB) spanning multiple Availability Zones (AZs) to the VPC in the us-east-1 Region. Deploy EC2 instances across multiple AZs in each Region as part of an Auto Scaling group spanning both VPCs and served by the ALB.
• B. Deploy an Application Load Balancer (ALB) spanning multiple Availability Zones (AZs) to the VPC in the us-east-1 Region. Deploy EC2 instances across multiple AZs as part of an Auto Scaling group served by the ALB. Deploy the same solution to the us-west-1 Region. Create an Amazon Route 53 record set with a failover routing policy and health checks enabled to provide high availability across both Regions.
• C. Create a VPC in the us-west-1 Region. Use inter-Region VPC peering to connect both VPCs. Deploy an Application Load Balancer (ALB) that spans both VPCs. Deploy EC2 instances across multiple Availability Zones as part of an Auto Scaling group in each VPC served by the ALB. Create an Amazon Route 53 record that points to the ALB.
• D. Deploy an Application Load Balancer (ALB) spanning multiple Availability Zones (AZs) to the VPC in the us-east-1 Region. Deploy EC2 instances across multiple AZs as part of an Auto Scaling group served by the ALB. Deploy the same solution to the us-west-1 Region. Create separate Amazon Route 53 records in each Region that point to the ALB in the Region. Use Route 53 health checks to provide high availability across both Regions.

Correct answer: B

Explanation

Option B is correct because a multi-region active-passive architecture requires independent application stacks (including an Application Load Balancer and an Auto Scaling group) to be deployed in both the us-east-1 and us-west-1 Regions. Amazon Route 53 with failover routing and health checks is the proper mechanism to automatically redirect traffic from the primary region to the disaster recovery region during an outage. Options A and C are incorrect because an ALB and an Auto Scaling group are regional resources and cannot span across multiple regions, while Option D lacks the required failover routing policy configuration.