reverse proxy_

[Maxim Dounin]

Hello!

On Tue, Feb 16, 2010 at 04:25:21PM +0100, Fredrik Widlund wrote:

> 
> Hi,
> 
> I am setting up a reverse-proxy system with Nginx (0.8.32) both 
> as back-end and proxy. The system is used for delivering static 
> large files.
> 
> What I would like to achieve is caching the files on the proxies 
> as long as possible offloading the back-end. I would also like 
> the proxy to react to changes on the back-end, but without 
> retransmitting already cached unmodified content.
> 
> My problem is that I'm not able to get the proxy to revalidate 
> unmodified static content  without retransmitting the already 
> cached file. E.g. if I set proxy_cache_valid for 200/OK 
> delivered content to 60 minutes the proxy won't react to changes 
> in the back-end for that period of time, and if I set it to 1 
> minute the file will be retransmitted from back-end to proxy 
> every minute, if requested from the proxy by a client. What I 
> would like is, for example, for the proxy to revalidate cached 
> content with I-M-S set to the time of the content being cached 
> and if not modified refreshing the validity of the previously 
> cached content and returning it to the client.
> 
> I've looked through the documentation and played with 
> cache-control directives like for example pre/post-check without 
> succeeding in creating this behaviour. There probably is an 
> obvious answer to this question, only I haven't been able to 
> find it.

It's not currently supported.

Maxim Dounin