Confused about proxy_buffer_size and proxy_buffers

[Igor Sysoev]

On Wed, Apr 30, 2008 at 11:15:14AM +1000, Dave Cheney wrote:

> Hi,
> 
> 	I am trying to tune our nginx frontends (proxying a pack of 
> 	mongrels)  to avoid this type of message
> 
> 2008/04/30 11:06:50 [warn] 35585#0: *40967931 an upstream response is  
> buffered to a temporary file /opt/local/var/run/nginx/proxy_temp/ 
> 0/58/0000370580 while reading upstream, client: 202.129.81.166,  
> server: www.redbubble.com, request: "GET /people/basiamc/art/732916-4- 
> fire-fairy? HTTP/1.0", upstream: 
> "http://172.16.0.76:8006/people/basiamc/art/732916-4-fire-fairy ", host: 
> "www.redbubble.com", referrer: 
> "http://www.redbubble.com/people/basiamc/art/732916-4-fire-fairy "
> 
> 	A little bit of curling reveals that our minimum page size is 
> 	between  11k and 14k, but can be up to 35k for the common pages. So I have 
> set
> 
> 	proxy_buffer_size 32k
> 
> 	In the expectation that this buffer will be allocated for all proxy  
> requests before the overflow into proxy_buffers.
> 
> 	For pages that have a large number of comments the sizes can range 
> 	up  to 150k but even with a setting like this
> 
> 	proxy_buffers 128	4k;
> 
> 	which should yield a maximum buffer of 546k, this request
> 
> [dave at crimson ~]$ curl -I 
> http://www.redbubble.com/people/basiamc/art/732916-4-fire-fairy
> HTTP/1.1 200 OK
> Server: nginx
> Date: Wed, 30 Apr 2008 01:13:45 GMT
> Content-Type: text/html; charset=utf-8
> Connection: keep-alive
> Set-Cookie: _session_id=1263f18e47b978d84cab76592cf240c4; path=/
> Cache-Control: private, max-age=0, must-revalidate
> Content-Length: 282541
> 
> 	Generates a warning.
> 
> 	Should I continue to increase the buffer size? Should I allocate the 
> buffer in larger sizes? Is there an interaction with proxy_buffers and  
> gzip or the output buffer settings ?

No, these buffers should be enough.
Are you sure that nginx was successfully reconfigured ?
Is nginx -t OK ?

Could you create debug log of the sinlge connection ?

BTW I think that
   proxy_buffer_size  16k;
   proxy_buffers      32   16k;


-- 
Igor Sysoev
http://sysoev.ru/en/