This module allows sites using CloudFront as a CDN to send 'Invalidate' requests for nodes that have been updated when the site cache is cleared. This helps get around CloudFront's 3 active Invalidation request limit and to cut down on the total file invalidations (CF charges for > 3000). E.g., a node can be edited multiple times but only invalidated once when the cache is cleared.
It also supplies a form that can be used to manually specify URLs to be invalidated (e.g. a PDF file's content was changed but name didn't, and the like).