AWS Certified Solutions Architect – Associate (SAA-C03) — Question 780

A solutions architect runs a web application on multiple Amazon EC2 instances that are in individual target groups behind an Application Load Balancer (ALB). Users can reach the application through a public website.

The solutions architect wants to allow engineers to use a development version of the website to access one specific development EC2 instance to test new features for the application. The solutions architect wants to use an Amazon Route 53 hosted zone to give the engineers access to the development instance. The solution must automatically route to the development instance even if the development instance is replaced.

Which solution will meet these requirements?

Answer options

• A. Create an A Record for the development website that has the value set to the ALB. Create a listener rule on the ALB that forwards requests for the development website to the target group that contains the development instance.
• B. Recreate the development instance with a public IP address. Create an A Record for the development website that has the value set to the public IP address of the development instance.
• C. Create an A Record for the development website that has the value set to the ALB. Create a listener rule on the ALB to redirect requests for the development website to the public IP address of the development instance.
• D. Place all the instances in the same target group. Create an A Record for the development website. Set the value to the ALB. Create a listener rule on the ALB that forwards requests for the development website to the target group.

Correct answer: A

Explanation

Option A is correct because routing traffic through the ALB to a dedicated target group ensures high availability and abstraction; if the development instance is replaced, the Auto Scaling group or administrator can register the new instance to the same target group, and the ALB will automatically forward traffic to it. Options B and C are incorrect because hardcoding or redirecting to a specific public IP address will fail when the instance is replaced and receives a new IP. Option D is incorrect because putting all instances in a single target group would distribute development traffic across both production and development instances instead of isolating it to the development instance.