Which solution will meet these requirements?
Create a read replica of the DB instance.
Create a template of the DB instance by using AWS CloudFormation.
Take frequent snapshots of the DB instance. Store the snapshots in Amazon S3.
Modify the DB instance to be a Multi-AZ deployment.
Explanations:
Creating a read replica allows for improved read performance and can help with load balancing, but it does not provide automatic failover for the primary DB instance. In the event of a failure, the read replica would not become the primary automatically, thus not meeting the high availability requirement with a recovery time of less than 5 minutes.
AWS CloudFormation templates allow for infrastructure as code and can be used to deploy resources, but they do not provide any inherent high availability or failover capabilities. If the primary DB instance fails, creating a new instance from a template would not meet the 5-minute recovery time requirement, as it would involve manual steps and potentially longer provisioning times.
Taking frequent snapshots provides a backup mechanism but does not ensure high availability or quick recovery. Snapshots can be used to restore the DB instance but involve a recovery process that can exceed the 5-minute requirement, especially if restoring from S3. This option does not address the need for minimal downtime.
Modifying the DB instance to be a Multi-AZ deployment ensures high availability by automatically replicating the database across multiple Availability Zones. In case of a failure of the primary instance, Amazon RDS automatically fails over to the standby instance in another AZ, which typically happens within minutes, thus meeting the requirement of a recovery time of less than 5 minutes.
I outline that the answer is:
Modify the DB instance to be a Multi-AZ deployment.