AWS Budgets, Budget Alerts, Cost Anomaly Detection, and Rightsizing Recommendations

Owned by Peter Murray
Last updated: Aug 04, 2023Version comment
2 min read

Reporting by AWS Cost Review Group

The AWS Cost Review Group (ACRG) annually projects a total budget for AWS costs.  The ACRG reviews and updates the budget as needed after each flower release.

Factors guiding the estimate may include:

  • The number of dev teams expected based on the roadmap and planned feature development.
  • The prior year's costs.  The current assumption is that AWS costs have generally been stable year-to-year.
  • The monthly and total cost estimates for ongoing environments listed in the COSTS Jira project.

Additionally, the ACRG keeps a spreadsheet of monthly subtotals by AWS service to detect trends in individual AWS service costs. The ACRG reports significant variations in monthly expenses to the Community Council for its budget planning purposes.

Budgets and Budget Alerts

There are four budgets defined in the FOLIO account at the moment:

  1. Daily non-covered costs: This budget is a daily sum of all AWS services that don't have a long-term contract to reduce costs (e.g., it doesn't include EC2 instances—covered by savings plans, RDS databases—covered by reserved instances). An alert is set for when the daily amount goes over $300; that alert goes to the #folio-aws-chatbot channel on Slack.
  2. Savings plan coverage: This budget looks at the percentage of the project's EC2 utilization covered by an AWS Savings Plan. An alert is set for when the daily coverage amount falls below 93%, with alerts going to the same Slack channel.
  3. RDS reservation coverage: This budget calculates the percentage of RDS usage that is covered by a reserved instance reservation and alerts if the coverage falls below a set percentage (currently 50%).
  4. Monthly cost budget: This budget covers all AWS costs for the month and alerts when the total monthly cost is above a set amount (currently $17,400).

Cost Anomaly Detection

The AWS Cost Anomaly Detection Monitor is a free service from Amazon that detects unusual spending patterns. It is set to send an alert when costs are 10% above historical projections.

Rightsizing Recommendations

To quote AWS: "The rightsizing recommendations feature in Cost Explorer helps you identify cost-saving opportunities by downsizing or terminating instances in Amazon Elastic Compute Cloud (Amazon EC2). Rightsizing recommendations analyze your Amazon EC2 resources and usage to show opportunities for how you can lower your spending. You can see all of your underutilized Amazon EC2 instances across member accounts in a single view to immediately identify how much you can save. After you identify your recommendations, you can take action on the Amazon EC2 console." These are available for review on the AWS console.