Re: Feedback to caches

>Perhaps a bit off-topic, but perhaps I have seen (and now lost
>reference to) some posting related to this on the list.
>
>Some caching protocols try to optimize the use of memory by
>determining which documents are more "popular" and pulling them
>towards clients, or pushing them away from servers. The popularity
>of a document is often if not always based on incoming requests.
>
>One difficulty with this approach is that once a document has been
>replicated elsewhere, and caching is effective, requests to the
>original source (be it the server or a proxy) are greatly reduced
>and this disturbs the protocol.
>
>Is there a way for a cache to provide feedback to the original
>source reporting access statistics for a given document ? Honestly
>I am not even sure if this is something that belongs to HTTP or
>not.  On one side, traffic related to cache-management (not directly
>generated by clients' requests) probably should travel separately;
>on the other side, clients' requests may have so many side effects
>on caches that it might be easier to mix the two things.
>
>	Luigi

This was raised as a very important issue at the W3C Demographics
workshop back in January. As a result the www-logging@w3.org mailing
list was created. A couple of working drafts have been written but
otherwise things seem to have stalled.

This work is crucial to caching. Already we are seeing plummetting
hit-rates as advertising funded services make their pages uncachable.

I know that there has been some discussion on this list, but the
possibly divergent solutions need to be tied together. The `token'
system is surely the more bandwidth efficient, but the feeling coming
from the advertising people is `we want the log of every transaction' -
why? - 'Because it's possible'.

Neil.

Received on Thursday, 11 April 1996 09:54:32 UTC