AWS Certified Solutions Architect – Associate (SAA-C03) — Question 543

A company runs an application that uses Amazon RDS for PostgreSQL. The application receives traffic only on weekdays during business hours. The company wants to optimize costs and reduce operational overhead based on this usage.

Which solution will meet these requirements?

Answer options

• A. Use the Instance Scheduler on AWS to configure start and stop schedules.
• B. Turn off automatic backups. Create weekly manual snapshots of the database.
• C. Create a custom AWS Lambda function to start and stop the database based on minimum CPU utilization.
• D. Purchase All Upfront reserved DB instances.

Correct answer: A

Explanation

The AWS Instance Scheduler is an AWS-provided solution that automates the starting and stopping of Amazon RDS instances based on a defined schedule, which directly reduces costs during off-hours with minimal operational effort. Disabling automatic backups (Option B) increases data loss risk, while custom Lambda functions (Option C) add unnecessary development and maintenance overhead. Purchasing Reserved Instances (Option D) reduces costs for continuously running workloads but does not address the requirement to optimize costs for a predictable, part-time schedule as efficiently as stopping the instances when not in use.