AWS Solutions Architect Associate Practice Test

Which of the following is part of the failover process for a Multi-Availability Zone Amazon RDS instance?

1. The failed RDS DB instance reboots.

2. The IP of the primary DB instance is switched to the standby DB instance.

3. The DNS record for the RDS endpoint is changed from primary to standby.

4. A new DB instance is created in the standby availability zone.

The correct answer is: The DNS record for the RDS endpoint is changed from primary to standby.

In a Multi-Availability Zone (Multi-AZ) Amazon RDS setup, failover is an essential feature designed to maintain high availability and minimize downtime. When a primary DB instance fails or is otherwise unavailable, the failover process is initiated, and part of this process involves handling DNS records. Changing the DNS record for the RDS endpoint from the primary to the standby instance allows applications that rely on that endpoint to seamlessly reconnect to the standby DB instance, which has taken over the primary role. This process ensures that the transition is smooth and minimizes disruption to service, as applications do not need to know the internal IP address of the new primary instance; they just continue to point to the RDS endpoint, which now directs traffic to the standby instance. Other processes, such as rebooting a failed instance or creating a new DB instance, are not directly part of the failover process in a Multi-AZ deployment. Specifically, the IP switching process is not user-managed as it is automatic and typically involves the internal handling of AWS’s infrastructure to ensure continuity. Thus, modifying the DNS record for the RDS endpoint is a critical action that helps maintain connectivity and availability during the failover process.