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Re: Combining Linked Data HTTP URIs and HTML5 WebSocket URIs

From: Patrick Logan <patrickdlogan@gmail.com>
Date: Sat, 19 Nov 2011 15:18:26 -0800
Message-ID: <CAD_aa-_NJoeNoK_kSwUcGVSM1MU=CqNyNTtL+BWxjXwdJ9mxWg@mail.gmail.com>
To: richard.hancock@3kbo.com
Cc: public-lod@w3.org
I'd like to hear ideas about that as well.

A few thoughts off the top of my head:

1. HTTP cache-control headers - "expires", "if-modified-since", etc.

2. For a custom web sockets protocol, similar header/meta information
could be part of the exchange.

3. Use XMPP + BOSH or web sockets for "pushing" changes.

Changes themselves could be described by Atom, RSS, or the ChangeSet
vocabulary ( http://vocab.org/changeset/schema.html ).

-Patrick


On Sat, Nov 19, 2011 at 2:05 PM,  <richard.hancock@3kbo.com> wrote:
> Thanks David, Kingsley and Patrick for the answers so far.
>
> maybe I should restate my question  as follows:
>
> With the current specs and definitions of Linked Data currently available,
> what is the best way to indicate that parts of the information being
> returned are dynamic?
>
> For the server examples below I could create an owl model with server
> status as a property, but how do I indicate that the value of status is a
> dynamic property which may change in the near future?
>
> What I would like is a Linked Data browser similar to Tabulator that can
> generically read my Linked Data and having discovered that a particular
> property is dynamic provide live updates of that property.
>
> To my mind HTML5 WebSockets have the potential to provide that dynamic
> functionality (though currently only via logic specific to a custom
> browser).
>
> So, (leaving aside HTML5 websockets for the moment) my initial question
> comes down to what is the best way to indicate that the values of some
> properties are dynamic?
>
> Cheers,
>
> Richard
>
>
>
>> The problem I am having coming to terms with your question is that the
>> web socket protocol is "full custom" once the two endpoints have
>> established that they are indeed using web sockets.
>>
>> The http protocol defines all kinds of details that continue from
>> connection through disconnection (e.g. what kind of data is being
>> exchanged).
>>
>> This seems kind of like designing for a gate array (http) vs. a full
>> custom IC. That's probably what you expect, and that's fine - it's
>> just you've created an ASIC -- an Application-Specific Integrated
>> Circuit.
>>
>> And so along the lines of what Kingsley wrote in his response, it
>> seems to me you could:
>>
>> * Design a vocabulary for describing servers and performance metrics
>> using any URL scheme.
>>
>> * Design (at least) two access mechanisms, one based on http and the
>> other based on web sockets. Clients of the latter would just have to
>> understand your application-specific protocol designed to transmit web
>> socket data frames to be formatted and parsed as you see fit.
>>
>> Either access mechanism could be used to communicate (subsets of) the
>> same graph.
>>
>> Potentially confused, I am...
>> -Patrick
>>
>> On Fri, Nov 18, 2011 at 6:22 PM,  <richard.hancock@3kbo.com> wrote:
>>> Hi All,
>>>
>>> I have a couple of questions re combining Linked Data HTTP URIs and
>>> HTML5
>>> WebSocket URIs.
>>>
>>> There are a couple of applications that I would like to build which have
>>> a
>>> mix of static and dynamic data. For the dynamic data I am planning to
>>> use
>>> HTML5 WebSockets [1][2] which uses the ws:// and wss:// prefixes.
>>>
>>> As an example I want to report the runtime status of the servers in a
>>> Weblogic cluster.  Using JMX monitoring to get the actual status I could
>>> use
>>>
>>>
>>> ws://www.3kbo.com:9090/servers/1/status
>>> ws://www.3kbo.com:9090/servers/2/status
>>>
>>> to display the current status of each server in my monitoring app.
>>>
>>> I am also planning to display LinkedData[3] about each server using the
>>> URIs
>>>
>>> <http://www.3kbo.com:8080/servers/1> and
>>> <http://www.3kbo.com:8080/servers/2>.
>>>
>>> It would seem logical to use owl:sameAs to combine the HTTP URIs and the
>>> Websocket URIs to assert that they are referring to the same
>>> individuals,
>>> but is that valid?
>>>
>>> I.e. can the following two statements be made in OWL?
>>>
>>> <http://www.3kbo.com:8080/servers/1> owl:sameAs
>>> <ws://www.3kbo.com:9090/servers/1> .
>>>
>>> <http://www.3kbo.com:8080/servers/2> owl:sameAs
>>> <ws://www.3kbo.com:9090/servers/2> .
>>>
>>> Does the forth LinkedData[3] principal
>>>
>>> "4. Include links to other URIs. so that they can discover more things."
>>>
>>> implicitly include links to Websocket URIs ?
>>>
>>> Cheers,
>>>
>>> Richard Hancock
>>>
>>>
>>> 1. http://en.wikipedia.org/wiki/WebSockets
>>> 2. http://dev.w3.org/html5/websockets/
>>> 3. http://www.w3.org/wiki/LinkedData
>>>
>>>
>>>
>>
>
>
>
Received on Saturday, 19 November 2011 23:18:55 UTC

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