AWS Certified SysOps Administrator – Associate — Question 453

An application runs on Amazon EC2 instances in an Auto Scaling group. Following the deployment of a new feature on the EC2 instances, some instances were marked as unhealthy and then replaced by the Auto Scaling group. The EC2 instances terminated before a SysOps administrator could determine the cause of the health status changes. To troubleshoot this issue, the SysOps administrator wants to ensure that an AWS Lambda function is invoked in this situation.
How should the SysOps administrator meet these requirements?

Answer options

• A. Activate the instance scale-in protection setting for the Auto Scaling group. Invoke the Lambda function through Amazon EventBridge (Amazon CloudWatch Events).
• B. Activate the instance scale-in protection setting for the Auto Scaling group. Invoke the Lambda function through Amazon Route 53.
• C. Add a lifecycle hook to the Auto Scaling group to invoke the Lambda function through Amazon EventBridge (Amazon CloudWatch Events).
• D. Add a lifecycle hook to the Auto Scaling group to invoke the Lambda function through Amazon Route 53.

Correct answer: C

Explanation

Adding an Auto Scaling lifecycle hook pauses the termination process, putting the instance into a Wait state, which provides the necessary time to run troubleshooting tasks and trigger an AWS Lambda function via Amazon EventBridge. Scale-in protection only prevents instances from being terminated during scale-in events and does not address health check replacements. Amazon Route 53 is a DNS service and cannot be used to detect Auto Scaling state changes or trigger Lambda functions directly in this scenario.