Re: [squid-users] Predictive caching?

ons 2003-07-23 klockan 02.08 skrev Bob Arctor:
> squid could just CONNECT with all links available on the page.
> then it could check for available bandwitch and crawl thru site searching all
> html pages (and caching them), not entering those which are dynamically
> created.

As Robert tried to say there is a number of technical obstacles here
which makes predictive caching very tricky unless you are willing to
waste a lot of bandwidth.

* It is impossible to tell if the reply is going to be dynamically
generated by looking at the URL. This is only known once you see the
reply. By looking at the URL you can only guess what the result may be.

* It is also not fully possible to tell what the browsers request for
the URL will look like before you see the request. There is such things
like Cookies etc which makes it hard to accurately predict what the
request will look like.

* It is impossible to tell if the object will be cacheable before
actually seeing the resulting object..

* It is impossible to tell the size of the object before actually seeing
the resulting object.

* You also do not know that the browser will request these objects. The
browser may have the objects already cached, disabled loading of inline
images, or the user may simply move on to another page before the
browser fetches the objects (I am pretty sure most of you have done
this.. clicking on a link, closing the window or using the back button
while images are still loading)

Regards
Henrik

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