In Aurora Multi-AZ clusters, changing the storage class (e.g., gp2 → gp3) is applied seamlessly to all cluster nodes because Aurora storage is shared and distributed, so downtime is minimal to none.
Most storage class changes (gp2 → gp3) are applied online with minimal or no downtime, especially in Multi-AZ deployments, because the standby ensures high availability.
If we change the storage type of the primary RDS instance (e.g., from gp2 → gp3), the standby instance is automatically updated to match the same storage class. You don’t need to manually change the standby — AWS handles it for you.
Standby DB instance because to avoid performance impact
Yes, we can associate a Route 53 Private Hosted Zone with an RDS instance in a private subnet and it’s actually a best practice for private databases.