A method includes receiving, at a first server from a second server, a first file attribute associated with a file. The method includes making a determination, at the first server based on the first file attribute, of availability of a classification for the file from a cache of the first server. The method includes, in response to the determination indicating that the classification is not available from the cache, sending a notification to the second server indicating that the classification for the file is not available. The method also includes receiving a first classification for the file from the second server at the first server. The first classification is generated by the second server responsive to the notification.