Sometimes cannot immediately access file after uploading

[DavidMikeSimon]

Sporadically, after uploading a file for a resource successfully, there's a short window during which the URL for the new file does not work; nginx simply hangs and will not respond to the request for that URL at that time. A few seconds later, requests start working correctly.

The most obvious culprit is NFS, but it's hard to say for sure.