AWS Certified DevOps Engineer – Professional — Question 48

A company recently migrated its legacy application from on-premises to AWS. The application is hosted on Amazon EC2 instances behind an Application Load
Balancer, which is behind Amazon API Gateway. The company wants to ensure users experience minimal disruptions during any deployment of a new version of the application. The company also wants to ensure it can quickly roll back updates if there is an issue.
Which solution will meet these requirements with MINIMAL changes to the application?

Answer options

• A. Introduce changes as a separate environment parallel to the existing one. Configure API Gateway to use a canary release deployment to send a small subset of user traffic to the new environment.
• B. Introduce changes as a separate environment parallel to the existing one. Update the application's DNS alias records to point to the new environment.
• C. Introduce changes as a separate target group behind the existing Application Load Balancer. Configure API Gateway to route user traffic to the new target group in steps.
• D. Introduce changes as a separate target group behind the existing Application Load Balancer. Configure API Gateway to route all traffic to the Application Load Balancer, which then sends the traffic to the new target group.

Correct answer: A

Explanation

Option A is correct because using a canary release allows for minimal disruption by directing only a small amount of traffic to the new environment, enabling easy rollback if issues arise. Option B does not provide a controlled rollout process. Option C focuses on gradual routing but does not emphasize the canary strategy. Option D sends all traffic to the new target group immediately, which increases the risk of disruptions.