[ogsa-d-wg] Discovery Service - Returning Data

[Mario Antonioletti]

Hi,
    Is it not the case that you may want some higher level service that 
given some metadata (or attributes) about the type of data that you are 
looking for will go and talk to services (discovery and data services), 
locate the data that matches your criteria and return it to the user. 
The user never be concerned about what the physical or logical name for 
that data was. In effect some sort of user broker or agent. That was
my understanding from the call.

I think this is a higher-level service that uses discovery services but 
is not necessarily a registry. I would agree with Peter that we do not
want to bind the discovery process with the content retrieval process
in the architecture. On the other hand if someone wants to create
such a combined beast then we should not necessarily put obstacles
in their way but that would be outwith the scope of the architecture.

 			Mario


On Thu, 16 Mar 2006, Dave Berry wrote:

> Allen,
>
> I'm also a bit concerned about this.  I apologise, because I didn't
> realise when we were discussing this on the call that you had taken the
> action to make this change - I was in too much of a hurry to move on to
> the next item.  My concern is that I don't know what it means to "return
> the data", in a context where we have several possible interfaces for
> accessing data, including ByteIO and the various DAIS specs, each of
> which operate on names.
>
> I don't think I understand Dieter's suggestion sufficiently well to 
see
> how it would affect the overall architecture.  It certainly sounds an
> interesting idea and if we can incorporate it simply then that's all to
> the good, but I'd rather we had a longer talk with Dieter first.
>
> Best wishes,
>
> Dave.
>
>  _____
>
> From: owner-ogsa-d-wg at ggf.org [mailto:owner-ogsa-d-wg at ggf.org] On Behalf
> Of Allen Luniewski
> Sent: 16 March 2006 16:59
> To: ogsa-d-wg at ggf.org
> Subject: Fw: Re: [ogsa-d-wg] Discovery Service - Returning Data
>
>
>
> Peter's mail bounced.
>
> Allen
>
> ----- Forwarded by Allen Luniewski/Almaden/IBM on 03/16/2006 08:54 AM
> -----
>
>
> Message-ID:
> <20570961.451142526276621.OPEN-XCHANGE.WebMail.tomcat at sala.cscs.ch>
> Date: Thu, 16 Mar 2006 17:24:36 +0100 (CET)
> From: Peter Kunszt <pkunszt at cscs.ch>
> To: ogsa-d-wg at ggf.org
> Subject: Re: [ogsa-d-wg] Discovery Service - Returning Data
>
>
>
> hi allen
>
> i don't know.. i get an uneasy feeling when service discovery
> is mixed with ontologies and content. to me, e.g. DNS is service
> discovery already,
> and certainly it does not give me the semantics or content of the
> service. i
> would separate any kind of content retrieval from service discovery, it
> feels
> 'cleaner' for a SOA. otherwise i'm afraid service discovery will be too
> large
> a beast to manage..
>
> just my swiss 2cents...
>
> cheers
> peter
>
> -----Urspr=C3=BCngliche Nachricht-----
> Von: owner-ogsa-d-wg at ggf.org im Auftrag von Allen Luniewski
> Gesendet: Mi 15.03.2006 18:26
> An: ogsa-d-wg at ggf.org
> Betreff: [ogsa-d-wg] Discovery Service - Returning Data
> =C2=A0
> At today's call, I took on an action to update the discovery service
> section to allow for discovery services that returned the data of
> interest
> rather than a reference to the data.=C2=A0 Here is the updated material
> for
> your=C2=A0 consideration:
> Resource Discovery
> Discovery services are vital to the data architecture.=C2=A0 The data
> services
> may use the discovery services not just for registering services
> themselves, but also for registering the data sets that are stored by
> those services. This requires languages or ontologies for describing
> data.
> Discovery services may also register the locations of schema
> definitions.
> Discovery services may be built upon metadata repositories that contain
> information about other entities in the grid such as resources, and
> services.=C2=A0 Some discovery services may return the name of the
> service
> and
> some may return an EPR to the service.=C2=A0 Some discovery services may
> ta=
> ke
> a
> description of the desired data as input and return the data itself.
>
>
> Allen
>
>
>
>
>

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|Mario Antonioletti:EPCC,JCMB,The King's Buildings,Edinburgh EH9 3JZ.   |
|Tel:0131 650 5141|mario at epcc.ed.ac.uk|http://www.epcc.ed.ac.uk/~mario/ |
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