has matured and now is available with a Freemium tier for monitoring your EC2 instance at no charge.
Amazon Cloudwatch allows you to monitor:
- CPU Load
- Disk Input / Ouput
- Network Input / Output
For your Amazon EC2 instances. The data is collected every five minutes and stored for two weeks.
In true essence of a Freemium model you can then upgrade to a more detailed monitoring for .0015 / per hour per instance.
If you are looking to take advantage of truly auto-scaling your Amazon EC2 infrastructure you need to start getting familiar with how Amazon CloudWatch works