AWS Certified Database – Specialty — Question 242

A company is using an Amazon RDS for MySQL DB instance for a production application. During the company’s upcoming scheduled maintenance window, a database specialist will perform a major version upgrade to the DB instance. The application is critical, so the company wants to minimize the maintenance time and allow for a rollback if a problem occurs.

Which solution will meet these requirements?

Answer options

• A. Enable the automatic upgrade option by using the AWS Management Console. Amazon RDS will apply the upgrade, which will occur during the scheduled maintenance window with no downtime.
• B. Create a new DB instance that has the desired version. Configure AWS Database Migration Service (AWS DMS) to migrate the existing data to the new DB instance. Change the DNS records to point to the new DB instance.
• C. Create read replica of the DB instance. Upgrade the version on the read replica. Promote the read replica to be the primary DB instance. Direct the application to use the read replica endpoint.
• D. Create a read replica of the DB instance. Configure a policy to fall over to the read replica if failure occurs during the upgrade. Upgrade the version on the primary DB instance.

Correct answer: C

Explanation

Option C is correct because it allows for an upgrade without affecting the primary operational database, enabling a seamless transition and rollback if necessary. Option A is incorrect as it does not provide a rollback mechanism. Option B involves creating a new instance, which can be time-consuming and complex. Option D does not ensure that the read replica is promoted before the upgrade, which could lead to downtime.