Cloudfront/CDN - reports on hits and usage.

To run a report on CloudFront to see which sites are using the most CDN calls and break it out by pricing, you can utilize several reporting features provided by Amazon CloudFront:

1. CloudFront Usage Charts: These charts in the AWS Management Console allow you to track trends in data transfer and requests (both HTTP and HTTPS) for each of your active CloudFront distributions. You can view usage from each CloudFront region at daily or hourly granularity, going back up to 60 days. This includes information on the number of requests and data transferred.

2. CloudFront Usage Report: This report is more detailed than the billing report and provides aggregate usage data by hour, day, or month. It lists operations by region and usage type, such as data transferred out of specific regions. You can download this report in XML or CSV format.

3. Billing Report: While less detailed than the usage report, the billing report provides a high-level view of all AWS service usage and charges, including CloudFront. It includes details such as product code, usage type, and usage quantity.

To break down the usage by pricing, you'll need to correlate the usage data with CloudFront's pricing tiers, which vary by region. The usage report will give you the most granular data to work with, as it provides information on data transfer and requests by region.

To access these reports:

1. Log in to the AWS Management Console
2. Navigate to the CloudFront service
3. Select "Reports & Analytics" from the navigation pane
4. Choose "Usage Reports" to view and download detailed usage data
5. For a quick view, select "Usage Charts" to see graphical representations of your CloudFront usage

By analyzing these reports, you can identify which of your distributions (sites) are using the most CDN calls and calculate the associated costs based on the pricing for each region and usage type.

Remember that while these reports provide valuable insights, they don't offer real-time data. There might be a delay of several hours before the most recent usage data appears in the reports.
Sources
Reports & Analytics for CDN Performance | Amazon CloudFront
AWS billing and usage reports for CloudFront - Amazon CloudFront
View CloudFront usage reports - Amazon CloudFront