Between 9:30 AM and 11:01 AM PST, customers may have seen elevated CloudFront API errors. Due to these API errors there was a backlog of changes that resulted in longer than usual change propagation delays for CloudFront configurations and invalidations. The backlog of Invalidation changes were fully processed by 11:35 AM. The backlog of CloudFront configuration changes was fully processed by 2:00 PM PST. All issues have been fully resolved and the system is operating normally.

from Amazon Web Services Service Status: