Help decipher error message "upstream prematurely closed connection while reading response header from upstream"

[Dave Cheney]

Your upstream, the server that nginx is proxying for closed the  
connection before sending a response back to nginx.

I'll take a guess that this is a rails app, and the upstream server is  
mongrel, turn on the mongrel debug log (kill -USR1 ?) and see if you  
can replicate the problem.

Cheers

Dave

On 03/05/2008, at 4:55 AM, Joe Van Dyk wrote:

> Anyone got any idea what this error means?
>
> 2008/05/02 11:38:31 [error] 5505#0: *357728 upstream prematurely
> closed connection while reading response header from upstream, client:
> 69.212.152.80, server: tanga.com, URL:
> "/puzzles/847-5-1-2008?comments_page=1#comment_188860", upstream:
> "http://10.7.217.165:9013/puzzles/847-5-1-2008?comments_page=1#comment_188860 
> ",
> host: "www.tanga.com", referrer:
> "http://www.tanga.com/comments/188860/edit"
>
> I'm not sure what the error message means, or where to look to debug  
> it.
>
> Thanks,
> Joe
>