[glue-wg] GLUE for describing resource requests (use case DGSI)

[Sergio Andreozzi]

Hi Alexander,

yep, now I get it right. The change you require is in the pipeline. Other
people already asked for the possibility to create individual fragments
without need for the hierarchical dependencies.
I will call for your and Mikael validation on the new version as soon as I
have it.


Cheers, Sergio


On 18 November 2010 18:42, <alexander.papaspyrou at tu-dortmund.de> wrote:

> Hi Sergio,
>
> probably, I wasn't too clear about what I wanted.
>
> Actually, we would like to see element-per-type approach that JSDL took.
> There, if you need a specific part of the JSDL to be "torn out" and reused
> somewhere else (let's say, in some other context where only the "Application
> Part" is of interest), you can just do this, because every type (class in
> Java-speak) in the XSD has a corresponding element (instance in Java-speak).
> With GLUE which doesnt have this in the current state of the XML rendering),
> you need to build a full GLUE document and fill several mandatory elements
> with nonsense data, just because you need some low-level fragment to express
> a certain issue.
>
> My only concern was that this fragment usage will be allowed in the
> end-of-the-year version of the GLUE XSD, and I wanted to make sure it is :-)
>
> Best,
> Alexander
>
> Am 18.11.2010 um 14:43 schrieb Sergio Andreozzi:
>
> > Hi Alexander,
> >
> > the final XSD for GLUE 2.0 is expected by the end of the year.
> >
> > Concerning the integration with JSDL for resource requirements matching,
> this is still open to debate and falls in the area of PGI work.
> >
> > Nevertheless, the topic has been touched few times in the past. I can
> provide my vision:
> >
> > the current JSDL envisions a number of terms to be used to express
> requirements on resources. They are part of the JSDL specification therefore
> binding the resource description to the job description. A couple of years
> ago, in an OGF joint session (http://bit.ly/byqg5T), we discussed the idea
> of separating them in order to easy the evolution of resource models
> independently from JSDL. Requirements are usually expressed as constraints
> on resource properties, therefore the idea could be to enable to express
> them as XPath/XQuery expressions on the resource description. An example is
> given in Section 5.3 of this OGF document:
> http://ogf.org/documents/GFD.137.pdf
> >
> > Expressing requirements as constraints on a resource description is the
> approach in place since years in the ClassAd language and its gLite JDL
> derivation. XPath/XQuery can be a translation into an XML world.
> >
> > Cheers, Sergio
> >
> >
> > On 18 November 2010 14:17, <alexander.papaspyrou at tu-dortmund.de> wrote:
> > Sergio,
> >
> > I think this boils down to more or less the old "allow fragments of GLUE
> to be used independently" debate we had in Brussels. Do we have a timeline
> for a version bump of the XML/XSD rendering, and will it be possible to
> render the XSD as it was done in JSDL (i.e. having an "xs:element" for each
> "xs:*Type*")?
> >
> > Best,
> > Alexander
> >
> > Am 18.11.2010 um 12:27 schrieb Mikael Högqvist:
> >
> > > Hi,
> > >
> > > I'm working in the DGSI project (a German D-Grid project) where our
> > > goal is to design and implement an interoperability framework between
> > > community schedulers and community bound resources. More specifically,
> > > this include protocols and services for delegation of activities as
> > > well as resources. We are primarily basing our protocols on OGF
> > > standards and recommendations and have tight collaboration with both
> > > the GRAAP (WS-Agreement/Negotiation) and DCI-Fed working groups within
> > > OGF.
> > >
> > > In the first information model we decided to use GLUE 2.0 for both
> > > resource descriptions and resource request specification. However
> > > describing resource requests with GLUE turned out to be difficult to
> > > implement. The main issue that we have is the restrictions in the GLUE
> > > 2.0 XML schema which makes it difficult to use only specific
> > > elements/group of elements in a document instance.
> > >
> > > For example, we would like to use the AccessPolicy element to describe
> > > requirements on who (e.g. DN/VO) is authorized to access a delegated
> > > resource. But to use this element, we need to create the entire
> > > hierarchy with Service/ComputingService/ComputingEndpoint and their
> > > respective required elements (e.g. ID, QualityLevel, ...) when using
> > > the GLUE 2.0 XSD.
> > >
> > > Currently, our solution is to use JSDL for specifying both activity
> > > and resource delegation requests. However, JSDL is not sufficient for
> > > all our use cases/requirements and we would like to use GLUE for
> > > specifying resource requests in our next version.
> > >
> > > Is there any work going on in the glue-wg to make the XSD rendering
> > > more lenient towards other use cases such as resource requirement
> > > specification? Or making it possible to use a subset of GLUE and
> > > combine it with other info models such as JSDL?
> > >
> > > Thank you in advance and Best Regards,
> > > Mikael Högqvist
> >
> >
> >
> >
> > --
> > Sergio Andreozzi - Policy Development Manager
> > EGI.eu - Amsterdam - The Netherlands - http://egi.eu
>
>


-- 
Sergio Andreozzi - Policy Development Manager
EGI.eu - Amsterdam - The Netherlands - http://egi.eu
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