Which solution will solve this problem?
Add a lifecycle hook to the Auto Scaling group to put the EC2 instance in a wait state until the log files have been delivered.
Configure a fixed response for the ALB to use custom error messages to respond to incoming requests with HTTP error response codes.
Create an Amazon CloudWatch alarm based on the RequestCountPerTarget metric for the Auto Scaling group. Modify the cooldown period to wait until the EC2 instance is terminated.
Update the launch configuration to enable scale-in protection for the Auto Scaling group and detach the EC2 instance protected for termination.
Explanations:
Adding a lifecycle hook to the Auto Scaling group will allow the EC2 instance to enter a wait state. This ensures that the log files can be delivered to the external system before the instance is terminated.
Configuring a fixed response for the ALB with custom error messages does not address the need for log delivery before termination. It only handles HTTP error responses and does not control the instance lifecycle or log delivery.
A CloudWatch alarm based on RequestCountPerTarget does not ensure that logs are delivered before the EC2 instance is terminated. It is used for scaling purposes, not for managing the termination process or log delivery.
Enabling scale-in protection and detaching the instance only prevents it from being terminated during a scale-in event. It does not address the need for log delivery before termination, which is the primary requirement.
If I’m correct, the answer is:
Add a lifecycle hook to the Auto Scaling group to put the EC2 instance in a wait state until the log files have been delivered.