# Proxy\_pass error: host not found in upstream **URL:** \ **Category:** NGINX\ **Created:** [May 10, 2010, 11:09am UTC](https://www.ruby-forum.com/t/proxy-pass-error-host-not-found-in-upstream/188331 "2010-05-10T11:09:29Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [May 10, 2010, 11:09am UTC](https://www.ruby-forum.com/t/proxy-pass-error-host-not-found-in-upstream/188331/1 "2010-05-10T11:09:29Z")
config file: server { listen [::]:80; server\_name [svn.php.net](http://svn.php.net); location /{ proxy\_pass [http://svn.php.net](http://svn.php.net); } } server { listen [::]:80; server\_name [upload.wikipedia.org](http://upload.wikipedia.org); location /{ proxy\_pass [http://upload.wikipedia.org](http://upload.wikipedia.org); } } # /usr/sbin/nginx -t [emerg]: host not found in upstream “[upload.wikipedia.org](http://upload.wikipedia.org)” in /etc/nginx/sites-enabled/blocked-reverse-proxy:12 configuration file /etc/nginx/nginx.conf test failed I set the similar server block for reverse proxying [svn.php.net](http://svn.php.net) and [upload.wikipedia.org](http://upload.wikipedia.org) , while [svn.php.net](http://svn.php.net) passed the config test but [upload.wikipedia.org](http://upload.wikipedia.org) NOT. Why? # /usr/sbin/nginx -V nginx version: nginx/0.7.64 TLS SNI support enabled configure arguments: --conf-path=/etc/nginx/nginx.conf –error-log-path=/var/log/nginx/error.log –pid-path=/var/run/nginx.pid --lock-path=/var/lock/nginx.lock –http-log-path=/var/log/nginx/access.log –http-client-body-temp-path=/var/lib/nginx/body –http-proxy-temp-path=/var/lib/nginx/proxy –http-fastcgi-temp-path=/var/lib/nginx/fastcgi --with-debug –with-http\_stub\_status\_module --with-http\_flv\_module –with-http\_ssl\_module --with-http\_dav\_module –with-http\_gzip\_static\_module --with-mail --with-mail\_ssl\_module –with-ipv6 –add-module=/tmp/buildd/nginx-0.7.64/modules/nginx-upstream-fair It’s the debian package. – Ren Xiaolei ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [May 10, 2010, 2:47pm UTC](https://www.ruby-forum.com/t/proxy-pass-error-host-not-found-in-upstream/188331/2 "2010-05-10T14:47:51Z")
On Mon, May 10, 2010 at 5:15 PM, Igor S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Host [upload.wikipedia.org](http://upload.wikipedia.org) not found: 3(NXDOMAIN) > Thank you for pointing out my mistake. > But I wonder why is the domain name resolved when testing config file? > I think NXDOMAIN should be a runtime error, not occured before nginx > runs. Or else, what would happen if the domain name is deleted during > nginx running? – Ren Xiaolei ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [May 10, 2010, 11:16am UTC](https://www.ruby-forum.com/t/proxy-pass-error-host-not-found-in-upstream/188331/3 "2010-05-10T11:16:31Z")
On Mon, May 10, 2010 at 05:08:34PM +0800, 任晓磊 wrote: > ``` > server_name upload.wikipedia.org; > > ``` > > I set the similar server block for reverse proxying [svn.php.net](http://svn.php.net) and > [upload.wikipedia.org](http://upload.wikipedia.org) , while [svn.php.net](http://svn.php.net) passed the config test but > [upload.wikipedia.org](http://upload.wikipedia.org) NOT. Why? > host [upload.wikipedia.org](http://upload.wikipedia.org) > Host [upload.wikipedia.org](http://upload.wikipedia.org) not found: 3(NXDOMAIN) – Igor S. > **[Igor Sysoev](http://sysoev.ru/en/)** ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [May 10, 2010, 3:05pm UTC](https://www.ruby-forum.com/t/proxy-pass-error-host-not-found-in-upstream/188331/4 "2010-05-10T15:05:25Z")
On Mon, May 10, 2010 at 08:46:53PM +0800, 任晓磊 wrote: > On Mon, May 10, 2010 at 5:15 PM, Igor S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Host [upload.wikipedia.org](http://upload.wikipedia.org) not found: 3(NXDOMAIN) > > Thank you for pointing out my mistake. > > But I wonder why is the domain name resolved when testing config file? > > I think NXDOMAIN should be a runtime error, not occured before nginx > > runs. Or else, what would happen if the domain name is deleted during > > nginx running? nginx resolves hosts at configuration phase, because for a long time nginx has no non-blocikng resolver. Currently it has, but resolves hosts at run-time only if proxy\_pass contains variables in any place, not necessarily in the host part. – Igor S. > **[Igor Sysoev](http://sysoev.ru/en/)** ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [May 10, 2010, 3:37pm UTC](https://www.ruby-forum.com/t/proxy-pass-error-host-not-found-in-upstream/188331/5 "2010-05-10T15:37:03Z")
On Mon, May 10, 2010 at 9:04 PM, Igor S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > nginx resolves hosts at configuration phase, because for a long time > nginx has no non-blocikng resolver. Currently it has, but resolves > hosts at run-time only if proxy\_pass contains variables in any place, > not necessarily in the host part. It’s difficult to communicate with you if I insist my old version. I will update my version as soon as possible. – Ren Xiaolei