AWS Certified Solutions Architect – Professional (SAP-C02) — Question 198

A company is running an application in the AWS Cloud. The core business logic is running on a set of Amazon EC2 instances in an Auto Scaling group. An Application Load Balancer (ALB) distributes traffic to the EC2 instances. Amazon Route 53 record api.example.com is pointing to the ALB.

The company's development team makes major updates to the business logic. The company has a rule that when changes are deployed, only 10% of customers can receive the new logic during a testing window. A customer must use the same version of the business logic during the testing window.

How should the company deploy the updates to meet these requirements?

Answer options

• A. Create a second ALB, and deploy the new logic to a set of EC2 instances in a new Auto Scaling group. Configure the ALB to distribute traffic to the EC2 instances. Update the Route 53 record to use weighted routing, and point the record to both of the ALBs.
• B. Create a second target group that is referenced by the ALDeploy the new logic to EC2 instances in this new target group. Update the ALB listener rule to use weighted target groups. Configure ALB target group stickiness.
• C. Create a new launch configuration for the Auto Scaling group. Specify the launch configuration to use the AutoScalingRollingUpdate policy, and set the MaxBatchSize option to 10. Replace the launch configuration on the Auto Scaling group. Deploy the changes.
• D. Create a second Auto Scaling group that is referenced by the ALB. Deploy the new logic on a set of EC2 instances in this new Auto Scaling group. Change the ALB routing algorithm to least outstanding requests (LOR). Configure ALB session stickiness.

Correct answer: B

Explanation

The correct answer is B, as it allows for the deployment of the new logic to a separate target group while using weighted target groups in the ALB, enabling the company to control the traffic distribution effectively. Option A would require managing multiple ALBs, which complicates the setup. Option C does not provide the required traffic control during the testing window, and option D does not address the stickiness requirement effectively, potentially leading to inconsistent experiences for users.