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@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@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