Cost Optimization: EC2 Right Sizing
Cost Optimization: EC2 Right Sizing

Implementation Considerations

Right-Sizing Recommendations

This solution offers recommendations as a starting point to help identify incorrectly sized Amazon EC2 instances. The resulting .csv file provides an analysis of each instance's provisioned size and utilization to help customers determine the most appropriate instance type for their workloads. For detailed information on how the results are calculated, see Appendix A: Right Sizing Logic.

This solution provides prescriptive instance type recommendations. Before incorporating these changes into your overall capacity management processes, we recommend that you test the proposed Amazon EC2 instances to ensure they are properly sized to fulfill their expected role.

Data Limits

Note that the CloudWatch metrics used in the analysis reflect the last two weeks of Amazon EC2 usage data. Therefore, be aware of the impact of seasonal or business cycles on the metrics and results.

The EC2 Right Sizing solution pulls utilization metrics for instances that are running or stopped (at the time of solution deployment) in order to provide recommendations for existing resources. This solution does not analyze usage or provide recommendations for instances that were terminated manually, as part of an Auto Scaling group, or for any other reason.

For customers who use Consolidated Billing to manage payment for multiple accounts, this solution will analyze Amazon EC2 instances only for the account in which it is deployed (whether that is the payer account or a different linked account).

Regional Deployments

This EC2 Right Sizing solution uses an AWS Lambda function to configure the stack resources, therefore you must deploy the solution in an AWS Region that supports AWS Lambda. For the most current AWS Lambda availability by region, see AWS service offerings by region. Once deployed, the solution will automatically analyze usage data for all Amazon EC2 instances in all AWS Regions of a customer’s account.


At the time of publication, this does not include AWS GovCloud (US), Asia Pacific (Singapore) Region, or China (Beijing) Region.