Re: [wsdm] Metadata approach

[Heather Kreger <kreger@us.ibm.com>]

see comments in line:

Heather Kreger
STSM, Web Services Lead Architect for SWG Emerging Technologies
Author of "Java and JMX: Building Manageable Systems"
kreger@us.ibm.com
919-543-3211 (t/l 441) cell:919-496-9572

"Sedukhin, Igor S" <Igor.Sedukhin@ca.com>

"Sedukhin, Igor S" <Igor.Sedukhin@ca.com>

10/24/2004 02:56 PM

To	<wsdm@lists.oasis-open.org>
cc
Subject	[wsdm] Metadata approach

I suggest that
 
1) metadata is expressed in the MUWS/MOWS documents where appropriate e.g.
 
    Capability A section
        Properties
            <propA>
            propA defines....
                metadata of the propA is
                    wsdm:xyz='abc'

<hk> I agree that we need to specify it in the MUWS spec, I would like to actually define the WSDM Qname for the metadata element and its schema.
In the WSDM-CIM mapping we need to represent CIM Qualifiers as metadata. Many of these CIM qualifiers have the same semantics as the WSDM ones and I would like to map those that do have matches to WSDM namespace metadata rather than CIM namespace metada. </hk>
 
2) WSDM does not make any normative assertions about how the metadata is expressed and accessed

<hk> I think its essential that WSDM does make normative assertions.

What about an MetadataAccess capability that allows us to get the metatdata for a specific QName as an interim solution? It could return back schema we identitfy.

Admittedly the timing is bad for WSDM 1.0. I don't think we can wait until WSDM 2.0<hk>
 
3) The specification composition is used in order to render metadata in XML documents and provide access to it. Partucular domains e.g. WS-CIM and implementations of WSDM manageability endpoint realize such specification composition as necessary.
 
For example, WSDM + WSRF-MD gives a solution where metadata expressed in WSDM is rendered according to WSRF-MD.
This is not any different than using WS-Policy with WSDM implementations.

<hk>Except there are scenarios for WSDM which require metadata to solve, i.e. the ability to find all properties of a capability programmatically, the ability to understand a metric's behavior. These are generic MUWS scenarios that should be addressed by MUWS and not domain specific. </hk>
 
4) WSDM specification has a a section such as the followwing
 
    Representing and accessing metadata
        Specification composition is to be used in order to represent metadata explicitly expressed in this specification.

<HK> I would like to at least call out that we should be composing in the specification from WS-RF. </hk>

--Igor Sedukhin.. (igor.sedukhin@ca.com)
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