Joshua Slive <joshua@xxxxxxxx> Sent by: jslive@xxxxxxxxx
20/12/2005 17:55
Please respond to
users@xxxxxxxxxxxxxxxx
To
users@xxxxxxxxxxxxxxxx
cc
Subject
Re: [users@httpd] reverse
proxy with cache ...
On 12/20/05, Wim.Van.Leuven@xxxxxx <Wim.Van.Leuven@xxxxxx>
wrote:
> So we have a central deployment server where we update the files.
The users on their
> PCs access however a reverse proxy caching server. The URL request
arrives at the
> proxy, it checks it cache to download or server the request from the
cache. The first user
> will fill the cache of the proxy; however all other users will be
served from the cache. If
> however we update a part of the application centrally, the cache should
get updated with
> the newer versions.
And how is the reverse proxy supposed to find out when there is an
update? You have three choices that I know of:
1. Have the proxy check every time. (Cache-Control: max-age=0 in
the
response headers)
2. Have the proxy check periodically and live with slightly-out-of-date
files.
3. Explicitly inform the cache of changes by making specially-crafted http
requests to the cache.
> Therefor at the site a apache server is setup as reverse proxy with
disk cache. The
> central server merely servers the files as static content. If I run
the proxy with debug
> tracing, I notice that the cache module does'nt cache anything with
the trace information
> "cache: no-cache or authorization forbids caching of ...".
Now you are changing the problem description. Before you said things
were cached but not updated. Now you are saying that they are not
cached. Which is it?
If things aren't getting cached, you need to check the http response
headers that are being sent with the content.
