Which solution will meet this requirement?
Deploy an additional NAT gateway in the other Availability Zones. Update the route tables with appropriate routes. Modify the RDS for MySQL DB instance to a Multi-AZ configuration. Configure the Auto Scaling group to launch the instances across Availability Zones. Set the minimum capacity and maximum capacity of the Auto Scaling group to 3.
Replace the NAT gateway with a virtual private gateway. Replace the RDS for MySQL DB instance with an Amazon Aurora MySQL DB cluster. Configure the Auto Scaling group to launch instances across all subnets in the VPC. Set the minimum capacity and maximum capacity of the Auto Scaling group to 3.
Replace the NAT gateway with a NAT instance. Migrate the RDS for MySQL DB instance to an RDS for PostgreSQL DB instance. Launch a new EC2 instance in the other Availability Zones.
Deploy an additional NAT gateway in the other Availability Zones. Update the route tables with appropriate routes. Modify the RDS for MySQL DB instance to turn on automatic backups and retain the backups for 7 days. Configure the Auto Scaling group to launch instances across all subnets in the VPC. Keep the minimum capacity and the maximum capacity of the Auto Scaling group at 1.
Explanations:
This option ensures that the application can run across multiple Availability Zones by deploying additional NAT gateways in each Availability Zone, allowing instances in private subnets to have redundancy for outbound traffic. Modifying the RDS instance to a Multi-AZ configuration enhances database availability and durability. The Auto Scaling group is also configured to scale across all subnets, improving resilience.
While replacing the RDS instance with an Amazon Aurora MySQL DB cluster provides additional benefits, the requirement specifically states that the existing application must operate across multiple Availability Zones. The solution does not include deploying NAT gateways across all Availability Zones, which could lead to single points of failure.
Replacing the NAT gateway with a NAT instance does not provide the same level of resilience as a NAT gateway, which is managed by AWS. Migrating to RDS for PostgreSQL does not inherently improve the application’s ability to run across multiple Availability Zones. Additionally, launching a new EC2 instance in another Availability Zone without an Auto Scaling group configuration does not ensure automatic scaling or resilience.
While deploying additional NAT gateways enhances resilience, modifying the RDS for MySQL instance to turn on automatic backups does not address the need for operating across multiple Availability Zones. Keeping the Auto Scaling group at a capacity of 1 does not allow for scaling, which contradicts the goal of enhancing availability and resilience across multiple Availability Zones.
I believe the answer is:
Deploy an additional NAT gateway in the other Availability Zones. Update the route tables with appropriate routes. Modify the RDS for MySQL DB instance to a Multi-AZ configuration. Configure the Auto Scaling group to launch the instances across Availability Zones. Set the minimum capacity and maximum capacity of the Auto Scaling group to 3.