AWS Certified Solutions Architect – Associate (SAA-C03) — Question 166

A company has a multi-tier application that runs six front-end web servers in an Amazon EC2 Auto Scaling group in a single Availability Zone behind an Application Load Balancer (ALB). A solutions architect needs to modify the infrastructure to be highly available without modifying the application.

Which architecture should the solutions architect choose that provides high availability?

Answer options

• A. Create an Auto Scaling group that uses three instances across each of two Regions.
• B. Modify the Auto Scaling group to use three instances across each of two Availability Zones.
• C. Create an Auto Scaling template that can be used to quickly create more instances in another Region.
• D. Change the ALB in front of the Amazon EC2 instances in a round-robin configuration to balance traffic to the web tier.

Correct answer: B

Explanation

Option B is correct because distributing instances across two Availability Zones enhances redundancy and availability. Option A is incorrect as it involves multiple Regions, which is more complex and not necessary for high availability. Option C does not address the immediate need for high availability within the existing setup. Option D does not improve availability but merely changes the traffic distribution method.