AWS Certified Solutions Architect – Associate (SAA-C03) — Question 944

A company recently launched a new application for its customers. The application runs on multiple Amazon EC2 instances across two Availability Zones. End users use TCP to communicate with the application.

The application must be highly available and must automatically scale as the number of users increases.

Which combination of steps will meet these requirements MOST cost-effectively? (Choose two.)

Answer options

• A. Add a Network Load Balancer in front of the EC2 instances.
• B. Configure an Auto Scaling group for the EC2 instances.
• C. Add an Application Load Balancer in front of the EC2 instances.
• D. Manually add more EC2 instances for the application.
• E. Add a Gateway Load Balancer in front of the EC2 instances.

Correct answer: A, B

Explanation

Because the application uses TCP for communication, a Network Load Balancer is the ideal choice for distributing traffic, whereas an Application Load Balancer is restricted to HTTP/HTTPS protocols. To meet the requirement of automatic scaling based on user demand, configuring an Auto Scaling group is necessary to dynamically adjust the instance count. Manually adding instances does not support automatic scaling, and a Gateway Load Balancer is intended for third-party virtual appliances rather than standard application load balancing.