Should upstream backends be disabled if they are down?

[Ezra Zygmuntowicz]

Hi Folks-

	I'm seeing some odd behavior with proxied backends. I had a cluster  
of 4 mongrels behind an nginx server with 4 entires in the upstream  
block. I took one of these mongrels down but did not change the  
upstream setting to only have 3 servers instead of 4. Nginx does not  
disable the backend that is no longer there though. Every 4th request  
will throw an error because there is no backend on that port

	Shouldn't nginx recognize that a backend is down and not send any  
more requests to that backend? It doesn't seem to recognize when a  
backend is down.

	I am not specifying any proxy_next_upstream directives so the default  
should be to move on to another backend right?

This is with nginx 0.6.6   and nginx 0.6.16 on
Linux 2.6.18-xenU #1 SMP Fri Jun 15 17:50:34 PDT 2007 x86_64 Intel(R)  
Xeon(R) CPU E5345 @ 2.33GHz GenuineIntel GNU/Linux

Thanks
- Ezra Zygmuntowicz
-- Founder & Software Architect
-- ezra at engineyard.com
-- EngineYard.com