How to Create a CloudWatch Billing Alarm & Send Notification to User When Threshold Crossed?
Step 1: Create a CloudWatch Billing Alarm which goes off when the estimated charges go above 500$.
Step 2: Create a CloudWatch Alarm which goes off to an Alarm state when the CPU utilization of an EC2 instance goes above 65%.
Step 3: Also add an SNS topic, so it notifies the person when the threshold is crossed.
For the detailed solution, please check this link: https://medium.com/devops-guides/how-to-create-a-cloudwatch-billing-alarm-send-notification-to-user-when-threshold-crossed-f8925c1fc5a2