How to send proxy cache status to backend server?

[Maxim Dounin]

Hello!

On Sat, Mar 15, 2014 at 01:14:51PM +0530, Makailol Charls wrote:

> I have been using add_header to send cache status to downstream server or
> client like this. This is working fine.
> add_header Cache-Status $upstream_cache_status;
> 
> Now I tried proxy_set_header to send header to upstream as below.
> proxy_set_header Cache-Status $upstream_cache_status;
> 
> But this could not send headers to upstream backend server. I think we can
> not use "$upstream_*"  variables to send headers to upstream backend.
> 
> Would you suggest me some way to send cache-status to backend upstream
> server?

The proxy_set_header directive works fine and passes 
$upstream_cache_status to backends without any problems.  Mostly 
likely you did something wrong in your tests.

-- 
Maxim Dounin
http://nginx.org/