Which strategy should the solutions architect use?
Review the Auto Scaling group settings and ensure the scheduled actions are specified to operate the Amazon EC2 instances during business hours only. Use 3-year scheduled Reserved Instances for the web server EC2 instances. Detach the internet gateway and remove the NAT gateways from the VPC. Use an Aurora Serverless database and set up a VPC endpoint for the S3 bucket.
Review the Auto Scaling group settings and ensure the scheduled actions are specified to operate the Amazon EC2 instances during business hours only. Detach the internet gateway and remove the NAT gateways from the VPC. Use an Aurora Serverless database and set up a VPC endpoint for the S3 bucket, then update the network routing and security rules and policies related to the changes.
Review the Auto Scaling group settings and ensure the scheduled actions are specified to operate the Amazon EC2 instances during business hours only. Detach the internet gateway from the VPC, and use an Aurora Serverless database. Set up a VPC endpoint for the S3 bucket, then update the network routing and security rules and policies related to the changes.
Use 3-year scheduled Reserved Instances for the web server Amazon EC2 instances. Remove the NAT gateways from the VPC, and set up a VPC endpoint for the S3 bucket. Use Amazon CloudWatch and AWS Lambda to stop and start the Aurora DB cluster so it operates during business hours only. Update the network routing and security rules and policies related to the changes.
Explanations:
Although it suggests using scheduled Reserved Instances, which would not save costs effectively for a temporary application, it does not mention removing the internet gateway, which is necessary since the application is only accessible from the company network. It also fails to emphasize the need for updating network routing and security rules after changes are made.
This option effectively proposes operating the EC2 instances only during business hours with Auto Scaling, removing the internet gateway, using an Aurora Serverless database, and setting up a VPC endpoint for the S3 bucket. It correctly highlights the need to update network routing and security rules, which is essential after making such architectural changes.
While it correctly suggests using an Aurora Serverless database and setting up a VPC endpoint, it lacks the specification for scheduling the EC2 instances during business hours and does not mention the need to update routing and security policies. The removal of the internet gateway is also not justified adequately since the application is still required to upload to S3.
This option suggests using 3-year scheduled Reserved Instances, which is not cost-effective for a temporary application. Although it recommends stopping the Aurora DB cluster during off-hours, it does not address the removal of the internet gateway, which is necessary since the application is accessible only from the company network. It also lacks clarity on updating the network routing and security rules.
I conclude that the answer is:
Review the Auto Scaling group settings and ensure the scheduled actions are specified to operate the Amazon EC2 instances during business hours only. Detach the internet gateway and remove the NAT gateways from the VPC. Use an Aurora Serverless database and set up a VPC endpoint for the S3 bucket, then update the network routing and security rules and policies related to the changes.