Upstream Read Timeout Upon Backend Server Offline

[mex]

if you REJECT from iptables you tell the client immediatly that the
service/port is not available, otherwise you run into timeouts, yes.
i'm not quite sure, but max_fails=3  x fail_timeout=30s == 90 seconds, until
your nginx fails over to the other
server.

regards,  

mex

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,238894,238918#msg-238918