AWS Certified SysOps Administrator – Associate — Question 273

A company has applications that process transaction requests multiple times each minute. The applications write transaction data to a single Amazon RDS DB instance. As the company begins to process more transactions, the company becomes concerned that it has no failover solution in place for disaster recovery (DR). The company needs the DB instance to fail over automatically without losing any committed transactions.

Which solution will meet these requirements?

Answer options

• A. Create an RDS read replica in the same AWS Region. Configure an AWS Lambda function to promote the replica as the primary DB instance during a DR scenario.
• B. Create an RDS read replica in a different AWS Region. Configure an AWS Lambda function to promote the replica as the primary DB instance during a DR scenario.
• C. Modify the DB instance to be a Multi-AZ deployment.
• D. Setup an Amazon CloudWatch alarm that monitors the DB instance memory utilization with a threshold greater than 90%. Invoke an AWS Lambda function to restart the DB instance.

Correct answer: C

Explanation

Converting the RDS instance to a Multi-AZ deployment enables synchronous replication to a standby instance in a different Availability Zone, which guarantees zero data loss and supports automatic failover. Read replicas (Options A and B) rely on asynchronous replication, meaning data loss can occur, and they require manual or custom-scripted failover mechanisms. Option D merely restarts the database based on memory thresholds, which does not address disaster recovery or automatic failover requirements.