[Pgi-wg] Sec: Agreement on WS-Naming (ref by strawman)

[m.riedel at fz-juelich.de]

Hi Aleksandr,

>- I would like to know what do You mean by "contacted". If that implies human 
user is expected to write EPR by hand to make his/her client to contact some 
service then I disagree.


I refer to contacted as "accessed from a Grid client" w/o avoiding to create the EPR manually - instead the EPR has an URI in wsa:To and maybe referenceproperties to point to a particular resource instance behind the service interface.

Q: Isn't A-REX not also accessible via EPRs?

Thanks for clarification,
Morris




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Morris Riedel
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----- Original Message -----
From: Aleksandr Konstantinov <aleksandr.konstantinov at fys.uio.no>
Date: Friday, March 20, 2009 12:40 pm
Subject: Re: [Pgi-wg] Sec: Agreement on WS-Naming (ref by strawman)

> On Friday 20 March 2009 12:21, Morris Riedel wrote:
> > Hi Aleksandr,
> > 
> > >-IMO the real question is what such EPRs may be used for. If 
> they planned
> > as
> > >-replacements for URLs and *full* such EPR is going to be put into
> > >-every SOAP header then I wohuld vote strongly against. But if 
> such EPR is
> > just a way
> > >-to describe service (same as corresponding section in Glue
> > >-document) and are ony meant to be used in some kind of information
> > system/port
> > >-then why not.
> > 
> > Just for clarification: With URLs you refer to the wsa:To 
> element of
> > WS-Addressing correct? If so, they are of course in any SOAP 
> message - or I
> > didn't get your point.
> 
> With URL I mean URL which was supposed to identify resource.
> Now with introduction of EPRs we get another layer of indirection 
> in resource
> identification. That's alright. But EPRs can also be used to 
> describe resource.
> And that description part may become lenghty. So if PGI goes for 
> EPR I would
> like to see it profiled which parts of EPR are expected/needed at 
> which place/moment.
> If my client application queries for some service with specific 
> capabilities 
> and gets 100kB EPR describing who where and how can contact 
> service that is
> probably ok. But if for contacting that service my application has 
> to insert that
> EPR into every SOAP message I would like to know which parts of it 
> I can be safely 
> removed in order to avoid buying dedicated optical link to 
> computing center hosting
> that service. :)  
> 
> > 
> > Also, if it would be only to put into a kind of information 
> system I would
> > vote for crunching the EPR in elements that can be probably 
> better searched
> > for by an query instead of putting information into EPR.
> 
> I just have to agree.
> 
> > 
> > Here, WS-Naming, provides basically a name of a service while 
> its EPR might
> > change over time (renewable reference). Also the document refers to
> > trackability of messages once you use WS-Naming (e.g. UUID 
> dependency) - so
> > I expect that this information of WS-Naming EPR additions should 
> be part of
> > any SOAP message. But that's only my interpretation from the 
> document.> 
> > 
> > Q: Can we agree that each functional service in the EPR space 
> such as
> > OGSA-BES are contacted with an pure EPR using URIs? We don't 
> consider> accessing a BESService simply with an URI - or do we?  I 
> would not vote for
> > that.
> 
> I would like to know what do You mean by "contacted". If that 
> implies human 
> user is expected to write EPR by hand to make his/her client to 
> contact some 
> service then I disagree.
> 
> 
> A.K.
> _______________________________________________
> Pgi-wg mailing list
> Pgi-wg at ogf.org
> http://www.ogf.org/mailman/listinfo/pgi-wg
> 



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