AWS Certified DevOps Engineer – Professional (DOP-C02) — Question 75

A company has an application that runs on a fleet of Amazon EC2 instances. The application requires frequent restarts. The application logs contain error messages when a restart is required. The application logs are published to a log group in Amazon CloudWatch Logs.
An Amazon CloudWatch alarm notifies an application engineer through an Amazon Simple Notification Service (Amazon SNS) topic when the logs contain a large number of restart-related error messages. The application engineer manually restarts the application on the instances after the application engineer receives a notification from the SNS topic.
A DevOps engineer needs to implement a solution to automate the application restart on the instances without restarting the instances.
Which solution will meet these requirements in the MOST operationally efficient manner?

Answer options

• A. Configure an AWS Systems Manager Automation runbook that runs a script to restart the application on the instances. Configure the SNS topic to invoke the runbook.
• B. Create an AWS Lambda function that restarts the application on the instances. Configure the Lambda function as an event destination of the SNS topic.
• C. Configure an AWS Systems Manager Automation runbook that runs a script to restart the application on the instances. Create an AWS Lambda function to invoke the runbook. Configure the Lambda function as an event destination of the SNS topic.
• D. Configure an AWS Systems Manager Automation runbook that runs a script to restart the application on the instances. Configure an Amazon EventBridge rule that reacts when the CloudWatch alarm enters ALARM state. Specify the runbook as a target of the rule.

Correct answer: D

Explanation

The correct answer is D because configuring an Amazon EventBridge rule to trigger the AWS Systems Manager Automation runbook allows for an automated response to the CloudWatch alarm, efficiently restarting the application without manual intervention. Options A and C rely on the SNS topic for triggering and may not be as efficient as using EventBridge. Option B does not involve the use of Systems Manager, which is necessary for handling the automation in a structured manner.