You can create an CloudWatch alarm that monitors an EC2 instance and automatically recovers the instance if it becomes impaired due to an underlying hardware failure or a problem that requires AWS involvement to repair.
A recovered instance is identical to the original instance, including the instance ID, private IP addresses, Elastic IP addresses, placement group and all instance metadata.
When the StatusCheckFailed_System alarm is triggered, and the recover action is initiated, you will be notified by the Amazon SNS topic that you selected when you created the alarm and associated the recover action.
When the process is complete, information is published to the SNS topic you've configured for the alarm.
You will notice an instance reboot on the recovered instance.