Re: Proxying PHP Pages

David J N Begley wrote:
> This isn't really going to help in this case as:
>
> 1. PHP pages aren't tied to ".php" extensions (some use ".php3", some
> use ".phtml", &c.); and,
>
> 2. this site appears to throw ALL its pages through the PHP parser, which
> means you'd have to add (gasp!) ".html" to your hierarchy_stoplist!

hierarchy_stoplist is not about caching, it is about not wasting time in
a cache hierarchy on uncacheable objects. If you are not in a cache
hierarchy then it makes no difference.

The default squid.conf has no caching problem with dynamic content. It
only becomes a problem if you have refresh patterns with a min age, or
if the server misbehaves and claims that the page is not modified when
Squid sends a IMS query.

> Yes, I think it'd be necessary to check the Squid access log to see why the
> user's having problems; certainly the site producing properly attributed HTTP
> headers (ie., caching things that can be cached and not caching those that
> cannot be cached) would be desirable in any case.

Sites should provide correct expiry or cachability information on their
dynamic content. If nothing is said then it is up to the cache
implementation (or administrator) to decide by any form of heuristic
algorithm of choice.

Some quotes from RFC2068:
...
   SHOULD
      This word or the adjective "recommended" means that there may
      exist valid reasons in particular circumstances to ignore this
      item, but the full implications should be understood and the case
      carefully weighed before choosing a different course.
...
   If neither Expires nor Cache-Control: max-age appears in the
   response, and the response does not include other restrictions on
   caching, the cache MAY compute a freshness lifetime using a
   heuristic. If the value is greater than 24 hours, the cache must
...

---
Henrik Nordstrom
Spare time Squid hacker