AWS Certified Solutions Architect – Professional (SAP-C02) — Question 521

A company is running an application on several Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. The load on the application varies throughout the day, and EC2 instances are scaled in and out on a regular basis. Log files from the EC2 instances are copied to a central Amazon S3 bucket every 15 minutes. The security team discovers that log files are missing from some of the terminated EC2 instances.
Which set of actions will ensure that log files are copied to the central S3 bucket from the terminated EC2 instances?

Answer options

• A. Create a script to copy log files to Amazon S3, and store the script in a file on the EC2 instance. Create an Auto Scaling lifecycle hook and an Amazon EventBridge rule to detect lifecycle events from the Auto Scaling group. Invoke an AWS Lambda function on the autoscaling:EC2_INSTANCE_TERMINATING transition to send ABANDON to the Auto Scaling group to prevent termination, run the script to copy the log files, and terminate the instance using the AWS SDK.
• B. Create an AWS Systems Manager document with a script to copy log files to Amazon S3. Create an Auto Scaling lifecycle hook and an Amazon EventBridge rule to detect lifecycle events from the Auto Scaling group. Invoke an AWS Lambda function on the autoscaling:EC2_INSTANCE_TERMINATING transition to call the AWS Systems Manager API SendCommand operation to run the document to copy the log files and send CONTINUE to the Auto Scaling group to terminate the instance.
• C. Change the log delivery rate to every 5 minutes. Create a script to copy log files to Amazon S3, and add the script to EC2 instance user data. Create an Amazon EventBridge rule to detect EC2 instance termination. Invoke an AWS Lambda function from the EventBridge rule that uses the AWS CLI to run the user-data script to copy the log files and terminate the instance.
• D. Create an AWS Systems Manager document with a script to copy log files to Amazon S3. Create an Auto Scaling lifecycle hook that publishes a message to an Amazon Simple Notification Service (Amazon SNS) topic. From the SNS notification, call the AWS Systems Manager API SendCommand operation to run the document to copy the log files and send ABANDON to the Auto Scaling group to terminate the instance.

Correct answer: B

Explanation

An Auto Scaling lifecycle hook allows you to pause the termination of an instance, putting it into a Terminating:Wait state so that custom tasks like log exporting can complete. By combining this hook with an Amazon EventBridge rule, an AWS Lambda function can be triggered to execute an AWS Systems Manager Run Command (SendCommand) to run the log-copying script on the instance. Once the script finishes, sending a CONTINUE signal to the Auto Scaling group allows the termination process to proceed successfully, whereas sending ABANDON or attempting to run scripts post-termination would fail.