RE: [wsdm] AI 242, 244 and 245

["Vambenepe, William N" <vbp@hp.com>]

Updated version that takes into account comments by Andrea (by email)
and Kirk (on the 10/13 conf call).

Regards,

William



As a generic and composable specification, WSDM MUWS can be used whether
or not a resource model exists for the resource that is made manageable
through MUWS. If a resource model (standard or not) exists for the
resource, WSDM MUWS provides ways to expose the elements of this model
(provided they are represented as XML elements or mapped to XML
elements) through Web services standards. In this case, the properties
of the manageable resource correspond to the appropriate model elements
for this resource, plus the MUWS-defined ResourceId property.

In addition, WSDM MUWS Part 2 and WS-ResourceLifetime define a set of
standard model elements, such as elements to represent relationships
among resources, a caption, the version, a human-readable description of
the resource, the operational status of the resource, etc... These
elements can be used if there is no resource model for the resource, in
addition to other resource-specific elements that might need to be
defined. Even if there is a model for the resource and if the model
contains element that semantically overlap the elements defined in MUWS
Part 2, the developer might choose to expose the information through
both sets of elements in order to maximize interoperability and make the
manageability information consumable by more managers.

In some cases, there is a resource model for the resources but the
resource model only provides ways to represent individual resources, not
to generate an XML document that represents the entire system. For such
cases where the resource model does not provide a way to aggregate
resources to provide a representation of the system, WS-ServiceGroup
provides one way to create that logical XML document. In this case the
system model is the resource properties document of a service group that
contains a set of resources. The relationships among these resources are
represented by model elements in the representation of the resources.
For example, through model elements defined by the resource model (e.g.
CIM associations) or through MUWS relationships elements.

The level of granularity at which parts of the model are being retrieved
through the operations defined by WSRF and WS-Notification does not have
to be the same as the level of granularity at which WSDM resources are
defined. It is for example possible to retrieve in one invocation an XML
document that contains the representation of a system made up of several
WSDM resources. Conversely, it is possible to retrieve small portions of
elements of model for a WSDM resource.