AWS Certified Solutions Architect – Associate (SAA-C03) — Question 394

A solutions architect is designing the architecture for a software demonstration environment. The environment will run on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The system will experience significant increases in traffic during working hours but is not required to operate on weekends.

Which combination of actions should the solutions architect take to ensure that the system can scale to meet demand? (Choose two.)

Answer options

• A. Use AWS Auto Scaling to adjust the ALB capacity based on request rate.
• B. Use AWS Auto Scaling to scale the capacity of the VPC internet gateway.
• C. Launch the EC2 instances in multiple AWS Regions to distribute the load across Regions.
• D. Use a target tracking scaling policy to scale the Auto Scaling group based on instance CPU utilization.
• E. Use scheduled scaling to change the Auto Scaling group minimum, maximum, and desired capacity to zero for weekends. Revert to the default values at the start of the week.

Correct answer: D, E

Explanation

Using a target tracking scaling policy based on CPU utilization allows the Auto Scaling group to dynamically scale instances up or down to match unpredictable traffic spikes during working hours. Scheduled scaling is the most efficient way to handle predictable weekend downtime, allowing the architect to reduce the Auto Scaling group capacity to zero to eliminate costs and restore it automatically on Monday. Scaling the ALB or internet gateway directly using AWS Auto Scaling is not supported, and deploying across multiple regions is unnecessary for a demonstration environment.