[Zope-dev] AW: [Summary] Caching prob with AHCM and headers

[Tres Seaver]

On Wed, 2003-09-17 at 07:26, Chris Withers wrote:
> Fred Yankowski wrote:
> >>>
> >>>	python: content.meta_type == 'Filesystem Image'
> >>
> >>Do you have any content with this metatype?
> > 
> > There is nothing in the portal_catalog with that meta_type.  But there
> > are lots of objects with that type:  most everything in
> > portal_skins/plone_images/, for example.
> 
> Oh, I getcha now... hmmm.. since these are served from disk anyway, what would 
> be the benefit in caching them?
> 
> (Dim memories suggest that OFS.Image.Image does some work to circumvent caching, 
> that's probabyl why they'er not being cached...)

Two reasons:

  - Browser caches know about the HTTP headers, too. 

  - Accelerators (Squid, Apache w/ mod_proxy and caching), cache content
    to reduce load on the appserver.

Both kinds of caching are Good Things (TM) for sites where Zope is or
can be the bottleneck, and where absolute freshenss is not a
requirement.  Even serving 304s is *much* slower in Zope than serving
from the Squid cache, for instance.

Tres.
-- 
===============================================================
Tres Seaver                                tseaver at zope.com
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