(Update From Amazon Website)
We’re excited to let you know that as of today, all Amazon EC2 instances come with free Basic Monitoring metrics from our Monitoring 
service, Amazon CloudWatch. You don’t need to do anything to make this happen. It’s there for you to use. Simply sign in to the AWS Management Console and select one of your active instances. You will immediately be able to view graphs and track performance on metrics such as CPU utilization, disk reads and writes, and network traffic.
Basic Monitoring for Amazon EC2 provides metric data on instance performance at five-minute frequency. Customers can optionally choose to enable Detailed Monitoring, which provides metric data at one-minute frequency for an additional $0.015 per instance-hour.
In addition, starting today you can now set alarms for any metric that Amazon CloudWatch monitors. You can configure these alarms via API call to send notifications or initiate Auto Scaling actions when metrics cross certain thresholds. Alarm pricing starts at $0.10 per alarm per month.
All the features mentioned above are available immediately in all regions (US-N. Virginia, US-N. California, EU-Ireland, APAC-Singapore), and we invite you to try them today! Learn more about Amazon CloudWatch at: aws.amazon.com/cloudwatch.
