AWS Certified Solutions Architect – Associate (SAA-C03) — Question 288

A company is experiencing sudden increases in demand. The company needs to provision large Amazon EC2 instances from an Amazon Machine Image (AMI). The instances will run in an Auto Scaling group. The company needs a solution that provides minimum initialization latency to meet the demand.

Which solution meets these requirements?

Answer options

• A. Use the aws ec2 register-image command to create an AMI from a snapshot. Use AWS Step Functions to replace the AMI in the Auto Scaling group.
• B. Enable Amazon Elastic Block Store (Amazon EBS) fast snapshot restore on a snapshot. Provision an AMI by using the snapshot. Replace the AMI in the Auto Scaling group with the new AMI.
• C. Enable AMI creation and define lifecycle rules in Amazon Data Lifecycle Manager (Amazon DLM). Create an AWS Lambda function that modifies the AMI in the Auto Scaling group.
• D. Use Amazon EventBridge to invoke AWS Backup lifecycle policies that provision AMIs. Configure Auto Scaling group capacity limits as an event source in EventBridge.

Correct answer: B

Explanation

Enabling Amazon EBS fast snapshot restore (FSR) on the underlying snapshot of an AMI eliminates the latency of I/O operations on blocks that are read for the first time, ensuring the EC2 instances deliver maximum performance immediately upon launch. Other options like AWS Step Functions, Amazon DLM, or AWS Backup do not address the storage initialization latency (pre-warming) required for rapid scaling.