Fastcgi_pass, resolver, and validating functionality.

[ahamilton9]

Almost. It was static group in the respect that it was dynamically grabbed
on load, but the resolver just wasn't triggering at all after that. 

We did not have an explicit group defined, "php" literally referred to the
DNS name of the load balancer it was contacting. The rest of the domain was
being taken care of by the local resolver (search domain). It looks like the
code changed in nginx to completely rely on it's own DNS checking at some
point rather than what the local system was reporting, which would explain
why it suddenly stopped working after a version change when nothing else had
been modified. 

We changed the line from "php:9000" to the FQDN like
"php.internal.ourdomain.com:9000", and the nginx resolver started
triggering. To anyone who isn't using an FQDN and stumbles upon this, try
that first.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,271373,271681#msg-271681