AWS Certified DevOps Engineer – Professional — Question 25

An application is deployed on Amazon EC2 instances running in an Auto Scaling group. During the bootstrapping process, the instances register their private IP addresses with a monitoring system. The monitoring system performs health checks frequently by sending ping requests to those IP addresses and sending alerts if an instance becomes non-responsive.
The existing deployment strategy replaces the current EC2 instances with new ones. A DevOps Engineer has noticed that the monitoring system is sending false alarms during a deployment, and is tasked with stopping these false alarms.
Which solution will meet these requirements without affecting the current deployment method?

Answer options

• A. Define an Amazon CloudWatch Events target, an AWS Lambda function, and a lifecycle hook attached to the Auto Scaling group. Configure CloudWatch Events to invoke Amazon SNS to send a message to the Systems Administrator group for remediation.
• B. Define an AWS Lambda function and a lifecycle hook attached to the Auto Scaling group. Configure the lifecycle hook to invoke the Lambda function, which removes the entry of the private IP from the monitoring system upon instance termination.
• C. Define an Amazon CloudWatch Events target, an AWS Lambda function, and a lifecycle hook attached to the Auto Scaling group. Configure CloudWatch Events to invoke the Lambda function, which removes the entry of the private IP from the monitoring system upon instance termination.
• D. Define an AWS Lambda function that will run a script when instance termination occurs in an Auto Scaling group. The script will remove the entry of the private IP from the monitoring system.

Correct answer: C

Explanation

Option C is the correct answer because it uses CloudWatch Events to invoke a Lambda function that removes the private IP from the monitoring system during instance termination, effectively preventing false alarms. Option A does not directly address the issue of false alarms since it involves SNS notifications rather than managing the IP entries. Option B, while it mentions a lifecycle hook, does not utilize CloudWatch Events for a seamless execution. Option D lacks the integration with CloudWatch Events, making it less efficient in managing the timing of the IP removal.