Use Amazon EC2 instances in an Auto Scaling group across multiple AZs paired with a Multi-AZ Amazon RDS DB instance for high availability and durability.

Utilize EC2 instances in a single AZ with an Auto Scaling group and deploy the database on an EC2 instance with Auto Recovery, addressing hardware but not AZ failures.

Employ EC2 instances in an Auto Scaling group across multiple AZs and an Amazon RDS DB instance with a read replica in a single AZ, promoting the replica for failover, to achieve high availability.

Place EC2 instances in an Auto Scaling group across multiple AZs and run primary/secondary databases on EC2 instances with EBS Multi-Attach for shared storage, which is not best practice for high availability.