Mark upstream proxy inoperable based on response body or arbitrary http status?

[vdavidoff]

I did something I am sure is terrible and hacked up the source so that I
could use http_302 along with proxy_next_upstream. This appears to do
what I want, though now I am not sure that HttpLimitReqModule can
actually do what I need.

Andy

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,229472,229489#msg-229489