November 08, 2012 06:07AM
Dave Nolan Wrote:
> >> However, this is not happening: I can watch tcpdump -n udp port 53
> but I
> >> see no re-resolution taking place.
> >>
> >> I'd love to know how to fix this. Any advice appreciated thanks!
> >
> > proxy_pass http://example.com$request_uri;
> >
> > will resolve "example.com" dynamically (assuming of course there's
> > no "upstream example.com" in configuration).
>
> Thanks very much for your help.
>
> If I switch to using example.com directly in the proxy_pass, I lose
> the
> flexibility of server groups. Is there any way of dynamically
> re-resolving servers in upstream server group?

Hi,

I can add that I lost my production servers last night because of this behavior.

* I use dynamic dns name for flexibility for almost all my servers
* I put one backend server to maintenance so the name was removed by dns (after a TTL)
* corosync manage my nginx servers... and can restart them.

You can easily understand what append :
corosync detect a problem, fail back to another server, restart nginx but nginx can't resolved a backend host in upstream so it failed to start (with "[emerg] host not found in upstream").

All my nginx servers have been down because of this.

Just like you, I can't remove my server groups but I want the flexibility of DNS resolving (Not failing at start and TTL).

--
Guilhem Lettron
Youscribe - www.youscribe.com
Subject Author Posted

resolver does not re-resolve upstream servers after initial cache

Dave Nolan November 07, 2012 03:42PM

Re: resolver does not re-resolve upstream servers after initial cache

Ruslan Ermilov November 08, 2012 02:36AM

Re: resolver does not re-resolve upstream servers after initial cache

Dave Nolan November 08, 2012 05:42AM

Re: resolver does not re-resolve upstream servers after initial cache

guilhem November 08, 2012 06:07AM

Re: resolver does not re-resolve upstream servers after initial cache

Sergey Budnevitch November 08, 2012 07:06AM

Re: resolver does not re-resolve upstream servers after initial cache

Dave Nolan November 09, 2012 04:16AM

Re: resolver does not re-resolve upstream servers after initial cache

nginxorg November 09, 2012 04:24AM

Re: resolver does not re-resolve upstream servers after initial cache

Sergey K. June 04, 2013 11:28AM

Re: resolver does not re-resolve upstream servers after initial cache

nginxorg November 09, 2012 04:26AM

Re: resolver does not re-resolve upstream servers after initial cache

Miroslav S. January 07, 2015 11:14PM

Re: resolver does not re-resolve upstream servers after initial cache

Maxim Dounin January 12, 2015 07:30AM



Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 228
Record Number of Users: 8 on April 13, 2023
Record Number of Guests: 421 on December 02, 2018
Powered by nginx      Powered by FreeBSD      PHP Powered      Powered by MariaDB      ipv6 ready