Simple proxy occasionally fails

[Maxim Dounin]

Hello!

On Tue, Aug 12, 2008 at 08:10:10PM -0700, Kris S. Amundson wrote:

>Simple proxy config fails occasionally with errors.  Apache and nginx are
>running on 4 web servers.  Nginx is used by the web app to proxy between two
>lucene/solr search servers.
>
>Nginx config on each web server:
>http://pastebin.com/m12448635
>
>Every so often I get a crit error:
>http://pastebin.com/m4dbfe328

It looks like you are facing firewall sometimes blocking 
connections to backend.  I've seen this happending with pf when 
new connection collide with already existing state in pf for 
connection in TIME_WAIT state.

Solution is to switch firewall off (or at least statefull part of 
it) for backend connections.

Maxim Dounin