Forum: NGINX help about how proxy_cache to store differet cache file by http header vary Accept-Encoding like squ

We use nginx as reserve proxy server and want use proxy_cache to replace
squid.
There are apache servers behind nginx, we use deflate module to compress
text/html pages.
The problem is if proxy_cache has cached the compressed page but the 
client
side that request page does not support uncompress, the page can not be 
see
correctly.
I know squid using http header Accept-Encoding to store different cache
file, but there is no way to use it in nginx proxy_cache_key.

Thanks
yahwist

On Thu, 2010-03-04 at 01:19 +0800, yangchunyu wrote:
> We use nginx as reserve proxy server and want use proxy_cache to replace squid.
> There are apache servers behind nginx, we use deflate module to compress text/html pages.
> The problem is if proxy_cache has cached the compressed page but the client side that request page does not support uncompress, the page can not be see correctly.
> I know squid using http header Accept-Encoding to store different cache file, but there is no way to use it in nginx proxy_cache_key. 

You can try to use proxy_cache_key to define caching key ( i don't
know however if you find variable that will do trick ).

The other method i would think of is not letting nginx to cache
compressed content. And i don't mean caching or not depend on
whether backend response is compressed or not - i mean forcing
uncompressed transmission between nginx and backends.
You may even gain another benefit - lessen the compression burden
on backends which may give you spare cpu cycles on them.

I believe
proxy_set_header  Accept-Encoding  "";
in proxying location is the way to go.

--
Miroslaw "Psyborg" Jaworski
GCS/IT d- s+:+ a C++$ UBI++++$ P+++$ L- E--- W++(+++)$ N++ o+ K- w-- O-
M- V- PS+ PE++ Y+ PGP t 5? X+ R++ !tv b++(+++) DI++ D+ G e* h++ r+++ y?

I think use proxy_cache_key to define caching key is good idea .
but I do not know which variable to use that can distinguish client side
support compressed or compressed content and store the different cache 
file.

Can Igor Sysoev help me . Thanks a lot.


                          yangchunyu


-----ÓʼþÔ­¼þ-----
·¢¼þÈË: Miros?aw Jaworski [mailto:mjaw@ikp.pl]
·¢ËÍʱ¼ä: 2010Äê3ÔÂ4ÈÕ 2:25
ÊÕ¼þÈË: nginx@nginx.org
Ö÷Ìâ: Re: help about how proxy_cache to store differet cache file by
httpheader vary Accept-Encoding like squid

On Thu, 2010-03-04 at 01:19 +0800, yangchunyu wrote:
> We use nginx as reserve proxy server and want use proxy_cache to replace
squid.
> There are apache servers behind nginx, we use deflate module to compress
text/html pages.
> The problem is if proxy_cache has cached the compressed page but the
client side that request page does not support uncompress, the page can 
not
be see correctly.
> I know squid using http header Accept-Encoding to store different cache
file, but there is no way to use it in nginx proxy_cache_key.

You can try to use proxy_cache_key to define caching key ( i don't
know however if you find variable that will do trick ).

The other method i would think of is not letting nginx to cache
compressed content. And i don't mean caching or not depend on
whether backend response is compressed or not - i mean forcing
uncompressed transmission between nginx and backends.
You may even gain another benefit - lessen the compression burden
on backends which may give you spare cpu cycles on them.

I believe
proxy_set_header  Accept-Encoding  "";
in proxying location is the way to go.

--
Miroslaw "Psyborg" Jaworski
GCS/IT d- s+:+ a C++$ UBI++++$ P+++$ L- E--- W++(+++)$ N++ o+ K- w-- O-
M- V- PS+ PE++ Y+ PGP t 5? X+ R++ !tv b++(+++) DI++ D+ G e* h++ r+++ y?


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nginx mailing list
nginx@nginx.org
http://nginx.org/mailman/listinfo/nginx

2010/3/5 杨春宇 <yangchunyu@soufun.com>:
> I think use proxy_cache_key to define caching key is good idea .
> but I do not know which variable to use that can distinguish client side
> support compressed or compressed content and store the different cache file.


Here's an example I've used. Of course the upstream server must return
compressed responses to HTTP/1.0 requests, which many do not by
default:
=================
#normalize all accept-encoding headers to just gzip or the empty string
  set $myae "";
  if ($http_accept_encoding ~* gzip) {
    set $myae "gzip";
    }
#the following prevents comressed responses from backend
  proxy_set_header Accept-Encoding $myae;
  proxy_pass http://backend;
#the following uses a combination of URI and the accept-encoding as a
proxy cache key
  proxy_cache_key "$host$request_uri$myae";
--
RPM

Thanks a lot, This solution is good

Thanks again!



        yahwist

-----邮件原件-----
发件人: Ryan Malayter [mailto:malayter@gmail.com]
发送时间: 2010年3月12日 13:10
收件人: nginx@nginx.org
主题: Re: help about how proxy_cache to store differet cache file by 
httpheader vary Accept-Encoding like squid

2010/3/5 î´º <yangchunyu@soufun.com>:
> I think use proxy_cache_key to define caching key is good idea .
> but I do not know which variable to use that can distinguish client side
> support compressed or compressed content and store the different cache file.


Here's an example I've used. Of course the upstream server must return
compressed responses to HTTP/1.0 requests, which many do not by
default:
=================
#normalize all accept-encoding headers to just gzip or the empty string
  set $myae "";
  if ($http_accept_encoding ~* gzip) {
    set $myae "gzip";
    }
#the following prevents comressed responses from backend
  proxy_set_header Accept-Encoding $myae;
  proxy_pass http://backend;
#the following uses a combination of URI and the accept-encoding as a
proxy cache key
  proxy_cache_key "$host$request_uri$myae";
--
RPM

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nginx mailing list
nginx@nginx.org
http://nginx.org/mailman/listinfo/nginx

You can also make the if block more complicated to remove
accept-encoding for types you know will not be compressed (.gif, .png,
.mpg, etc)

On Fri, Mar 12, 2010 at 7:38 AM, 杨春宇 <yangchunyu@soufun.com> wrote:
> 发送时间: 2010年3月12日 13:10
> compressed responses to HTTP/1.0 requests, which many do not by
> #the following uses a combination of URI and the accept-encoding as a
>
> _______________________________________________
> nginx mailing list
> nginx@nginx.org
> http://nginx.org/mailman/listinfo/nginx
>



--
RPM