Which solution will meet these requirements in the MOST operationally efficient manner?
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.
Create an AWS Lambda function that restarts the application on the instances. Configure the Lambda function as an event destination of the SNS topic.
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.
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.
Explanations:
Configuring an AWS Systems Manager Automation runbook to restart the application and linking it to the SNS topic is a valid approach. However, using SNS directly to invoke the runbook would not be the most efficient way to handle the automation. The solution lacks a direct mechanism for triggering the runbook without manual involvement.
A Lambda function can be used to restart the application on the instances. However, using an SNS topic directly to invoke the Lambda function to restart the application is not the most operationally efficient method. There is no direct link to CloudWatch Logs or the alarm triggering the event.
This option combines a Lambda function and an AWS Systems Manager Automation runbook, which is unnecessary for the solution. The Lambda function would invoke the runbook, but a simpler and more direct approach would be to trigger the runbook directly from CloudWatch Alarm or EventBridge.
This option leverages AWS Systems Manager Automation runbook triggered by an Amazon EventBridge rule, which is the most operationally efficient solution. It allows the automation to be triggered directly when the CloudWatch alarm enters the ALARM state, automating the application restart without manual intervention and without unnecessary Lambda functions.
As I recall, the answer is:
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.