W3C home > Mailing lists > Public > public-ldp-wg@w3.org > November 2014

Re: ldp wishlist for crosscloud

From: Ted Thibodeau Jr <tthibodeau@openlinksw.com>
Date: Mon, 10 Nov 2014 09:55:01 -0500
Cc: Linked Data Platform WG <public-ldp-wg@w3.org>
Message-Id: <6302C8AD-A939-45B5-94FC-809B416D8BB1@openlinksw.com>
To: Sandro Hawke <sandro@w3.org>
Sandro, all --

A couple of comments on initial skim...

On Nov 9, 2014, at 12:06 PM, Sandro Hawke <sandro@w3.org> wrote:

> == 2.  Change Notification to Web Servers
> 
> If a server acting on behalf of the end-user

i.e., acting as a Client against the other Servers.

The change publication/subscription should be implemented 
as a general Cilent-Server feature, something like, oh, 
say, PubSubHub.

> is going to aggregate data from other servers, it needs to be able to keep its copy in sync. Traditional web cache + polling works only when it's okay to be seconds or minutes out of date; many multi-user apps require much more responsiveness than that, so we see a need for one server to be able to subscribe to change notification from another.
> 
> One might want something like PATCH to make this more efficient, but at the moment it looks like we can keep the resources small enough that it doesn't matter.

The size of a single change notification resource may well be
tiny, but as the number of such notifications increase, both 
from one and many servers, efficiency is going to become more 
important.


> == 3.  Change Notification to Web Clients
> 
> Similarly, Web Apps often need to know immediately when data has changed.   While it might be nice to have this be the same protocol as (2), our preliminary investigation suggests the engineering trade-offs make that impractical.   So, this needs to be its own protocol. Probably it's just a tweak to the query protocol where query results, rather than being a single response collecting all the results, are ongoing add-result and remove-result events.

I think this is mostly a scale-of-payload kind of question.

The protocol should have (optimally client-specified) timing 
and/or number-of-changes parameters; this lets it remain one
protocol for both this "Just A Client" and the above "Server 
as Client" subscribers.


Regards,

Ted




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Received on Monday, 10 November 2014 14:55:30 UTC

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