Update : AWS CloudFormation adds Rollback Triggers Feature

Use Rollback Triggers to monitor the state of your application during the stack creation and update process. You can specify the alarms and the thresholds you want AWS CloudFormation to monitor, and if any of the alarms are breached, CloudFormation rolls back the entire stack operation to the previous deployed state.

from new feature http://ift.tt/2vAA1b9