AI 242, 244 and 245

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

Hi all,

As I started to write down explanations for these AIs, I started to
repeat the some information, so I decided to consolidate all three into
one explanation. How does the text below fit the bill?

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
example, the CIM model provides classes for many types of resources but
assumes that the system model will be accessed object by object, using
the interfaces defined by the WBEM framework. It doesn't, at least at
this point, provide a way to generate one XML document that represents
the content of a CIMOM (or a portion of it larger than just one
instance).

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 resource.