You can recover from instance failures using native Amazon capabilities or by restoring an instance from a Commvault backup. In addition, you can configure alarms from Amazon or alerts from Commvault:
Commvault alerts can provide notifications when operations encounter issues, or when environmental issues occur that might affect operations.
For Commvault components that run on Amazon EC2 instances, you can use alarms to detect issues that might affect your backup infrastructure. Amazon CloudWatch alarms can monitor Amazon EC2 instances and perform operations automatically. For example, you can create an alarm that recovers a failed instance, or an alarm that terminates an instance after it completes a task.
Automatic recovery of Amazon EC2 instances is available only for instances that do not use Auto Scaling.
You can also use alarms to detect availability zone and region failures, or to provide notification when your AWS account reaches quotas (service limits).
The following AWS documentation pages provide more information: