W3C home > Mailing lists > Public > ietf-http-wg-old@w3.org > January to April 1996

Re: Three working drafts related to demographics work.

From: <hallam@w3.org>
Date: Fri, 23 Feb 96 14:03:42 -0500
Message-Id: <9602231903.AA13396@zorch.w3.org>
To: "Sankar Virdhagriswaran, Crystaliz, Inc." <sankar@fcrao1.phast.umass.edu>
Cc: hallam@w3.org, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com

>I have some comments on your proxy notification proposal. Proxy-notification
>is a special case. In the future, clients may also inform servers that they
>can accept notifications. Therefore, limiting the offer of notification
>accpetance capability to proxies only is too limiting. You mention the
>client issues in your sub-section titled query, but I believe that it has
>not been thought through.

I realise that this could be used as a general client notification mechanism but 
the cost of servers notifying every browser of changes to a page is very high. A 
site might get connections from a million browsers in a day but the total number 
of large caches is probably in the tens of thousands and each large cache saves 
the main server a considerable amount of effort, thus more work on the part of 
the server is justified.

There is another issue, proxies and servers are gennerally present on a 
reliable, continuous basis. Clients are transient. 

I would like to see a client notification mechanism but would expect it to have 
a rather different nature, probably involving a degree of probabalistic fudge.


The application for the notification mechanism I described would be to enable a 
site to be administered from a single central server with load balancing 
achieved through a network of proxies. From the outside this would look like a 
set of replicated server but on the inside would be rather simpler to maintain 
than (say) an AFS partition mapped over the Atlantic.

>Notification is a fundamental concept, let us not wedge it in for only one use. 

I was trying to avoid making a proposal which would be interpreted as "Phill 
thinks that CNN should tell everyone in the world when there is a newsflash". 

We could weaken the statement by making it a matter of authorisation. CNN might 
be willing to offer the Hensa cache notification in return for Hensa supplying 
the missed log file info. CNN might be willing to supply Alice with notification 
in return for a 5cent microtransaction (e.g. MPTP :-).

Would people be happy with the suggestion in that case???

	Phill
Received on Friday, 23 February 1996 11:06:36 EST

This archive was generated by hypermail pre-2.1.9 : Wednesday, 24 September 2003 06:31:46 EDT