Tracking CloudFront Cache Results

With the latest update to Amazon CloudFront it cache result types from edge locations are now logged and available for analytics in Qloudstat as of today. The new edge result types reported are as follows:

  • Hit: CloudFront served the object to the viewer from the edge cache.
  • Refresh Hit: CloudFront found the object in the edge cache but it had expired, so CloudFront contacted the origin to verify that the cache has the latest version of the object.
  • Miss: The object wasn’t in the edge cache, so CloudFront requested the object from the origin and served it to the viewer.
  • Limit Exceeded: The request was denied because a CloudFront limit was exceeded.
  • Capacity Exceeded: CloudFront returned a 503 error because the edge location didn’t have enough capacity at the time of the request to serve the object.
  • Error: The request resulted in a client error (4xx) or server error (5xx).

You can drilldown these result types by edge locations and URI and vice versa for more insight.

Note: This will be effective September 12th, 2012 when the new log file format includes these changes.