How can the user configure this?
The user can get an email using SNS when the CPU utilization is less than 10%. The user can use the desired capacity of Auto Scaling to remove the instance
Use CloudWatch to monitor the data and Auto Scaling to remove the instances using scheduled actions
Configure CloudWatch to send a notification to Auto Scaling Launch configuration when the CPU utilization is less than 10% and configure the Auto Scaling policy to remove the instance
Configure CloudWatch to send a notification to the Auto Scaling group when the CPU Utilization is less than 10% and configure the Auto Scaling policy to remove the instance
Explanations:
SNS notifications can alert the user but cannot directly control Auto Scaling actions. The desired capacity would need to be manually adjusted, which isn’t automated based on CPU utilization.
Scheduled actions are used to scale based on a set schedule, not on dynamic metrics like CPU utilization. This doesn’t address the requirement to scale based on CPU utilization under 10%.
CloudWatch cannot directly send notifications to the Auto Scaling Launch Configuration, which is used to define instance settings, not control scaling actions. Scaling should be done by modifying the Auto Scaling group itself.
CloudWatch can monitor CPU utilization and send notifications to the Auto Scaling group. The Auto Scaling policy can then be configured to scale in (remove instances) based on the metric threshold (CPU < 10%).
I rank that the answer is:
Configure CloudWatch to send a notification to the Auto Scaling group when the CPU Utilization is less than 10% and configure the Auto Scaling policy to remove the instance