AWS Certified Solutions Architect – Associate (SAA-C02) — Question 777

A development team runs monthly resource-intensive tests on its general purpose Amazon RDS for MySQL DB instance with Performance Insights enabled. The testing lasts for 48 hours once a month and is the only process that uses the database. The team wants to reduce the cost of running the tests without reducing the compute and memory attributes of the DB instance.
Which solution meets these requirements MOST cost-effectively?

Answer options

• A. Stop the DB instance when tests are completed. Restart the DB instance when required.
• B. Use an Auto Scaling policy with the DB instance to automatically scale when tests are completed.
• C. Create a snapshot when tests are completed. Terminate the DB instance and restore the snapshot when required.
• D. Modify the DB instance to a low-capacity instance when tests are completed. Modify the DB instance again when required.

Correct answer: C

Explanation

Because the tests only run once a month, stopping the DB instance is not viable because Amazon RDS automatically restarts stopped instances after 7 days. Creating a snapshot and terminating the instance eliminates all instance hours charges during the 28 days of inactivity, making it the most cost-effective option. Other options like scaling down or using Auto Scaling still incur ongoing compute costs when the database is idle.