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

[vdavidoff]

I tried playing with proxy_intercept_errors and error_page to change
302s to 500s, then added http_500 to proxy_next_upstream, but this
doesn't seem to mark a proxy as down. I assume as far as
HttpUpstreamModule is concerned, the response is a 302, prior to it
being converted to a 500 (?).

Andy

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,229472,229487#msg-229487