AWS Certified DevOps Engineer – Professional (DOP-C02) — Question 85

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 it allows for a canary release deployment, which minimizes disruption by gradually shifting user traffic to the new environment, making it easier to roll back if issues arise. Option B does not provide the same level of control over traffic flow and does not facilitate a quick rollback. Options C and D involve changes to the existing target group, which could introduce complexities and potential downtime during the transition.