AWS Certified Solutions Architect – Associate (SAA-C03) — Question 621
A company hosts an application on Amazon EC2 On-Demand Instances in an Auto Scaling group. Application peak hours occur at the same time each day. Application users report slow application performance at the start of peak hours. The application performs normally 2-3 hours after peak hours begin. The company wants to ensure that the application works properly at the start of peak hours.
Which solution will meet these requirements?
Answer options
- A. Configure an Application Load Balancer to distribute traffic properly to the instances.
- B. Configure a dynamic scaling policy for the Auto Scaling group to launch new instances based on memory utilization.
- C. Configure a dynamic scaling policy for the Auto Scaling group to launch new instances based on CPU utilization.
- D. Configure a scheduled scaling policy for the Auto Scaling group to launch new instances before peak hours.
Correct answer: D
Explanation
Since the peak hours occur predictably at the exact same time every day, a scheduled scaling policy is the most effective solution to proactively spin up Amazon EC2 instances before the traffic surge begins. Dynamic scaling policies based on CPU or memory utilization are reactive, meaning they would only trigger after the load increases, resulting in temporary performance degradation during the initialization phase. An Application Load Balancer distributes existing traffic but does not scale the underlying compute capacity to handle the anticipated load spike.