Upgrade From Fedora 15 to 17: nginx Doesn't Work

[ptiseo]

Had nginx 1.0.5 running on a Fedora 15 system just fine for months.
Upgraded the server from F15 to F17. At first, all seems well, but over
time, I keep getting 500 errors on proxied sites. Logs say: "socket()
failed (24: Too many open files) while connecting to upstream". Has
anyone else had this experience? If so, what's the root cause?

Had to revert server back to a backup to get sites functional.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,227162,227162#msg-227162