AWS Certified SysOps Administrator – Associate (legacy) — Question 732

A streaming services company has a three-tier web application hosted on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer
(ALB). When the Auto Scaling group scales in, a deregistration delay occurs and the delay is sometimes longer than the time required to terminate the EC2 instance. A SysOps administrator must ensure that the latest logs are delivered to an external system before the EC2 instance is terminated.
Which solution will solve this problem?

Answer options

• A. 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.
• B. Configure a fixed response for the ALB to use custom error messages to respond to incoming requests with HTTP error response codes.
• C. 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.
• D. Update the launch configuration to enable scale-in protection for the Auto Scaling group and detach the EC2 instance protected for termination.

Correct answer: A

Explanation

An Auto Scaling lifecycle hook allows you to pause the termination of an EC2 instance, putting it into a Terminating:Wait state. This provides the necessary time to run custom actions, such as uploading the latest log files to an external system, before the instance is finally terminated. Other options like configuring ALB fixed responses, adjusting CloudWatch cooldown periods, or enabling scale-in protection do not gracefully pause the termination flow specifically for log collection purposes.