RE: [wsdm] [Omod] concepts diagram and words

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Management of Web services (MOWS) is a particular case of Management using Web services (MUWS) in which a resource is an element of the Web Services Architecture. The Web services concepts, according to WSDL, are defined as follows. A service is an aggregate of endpoints each offering the service at an address and accessible according to a bidning. A service has a number of interfaces that are realized by all of its endpoints. Each interface descibes a set of named messages that could be exchanged and their format. Properly formatted messages could be sent to an endpoint's address in a way prescribed by the binding. A description (document, artifact) is composed of definitions of interfaces and services. A description may contain both or either of the definitions.

An IT resource may bear some functional (e.g. business) responsibilities such as, for example, placement of an order. That would constitute a functional capability with the distinct semantics of placing an order. A functional resource is a composition of such capabilties. An endpoint may provide access to the functional resource and in that case would offer those capabilities. Such endpoint is called a functional endpoint. To offer a capability an endpoint has to realize interfaces. An interface that represents a functional capability is called a functional interface. One capability may be represented by many interfaces (e.g. various ways of representing the same semantics for different groups of target users).

The MUWS concepts are defined very similarily to the functional concepts (see MUWS spec). There is a manageable resource that is a resource composed of a number of manageability capabilities each represented by one or more manageability interfaces.

Management of Web services starts from an endpoint resource which, therefore, becomes manageable resource called manageable endpoint. The reason the endpoint is the basis element is that (1) anything behind an endpoint is a concrete implementation (e.g. an application hosted in a container), and (2) anything that builds on endpoints is a logical construct and therefore understaning of it has to be inferred. Both of the above are currently out of scope of this specification.

Because manageable endpoint is a manageable resource it is a composition of a number of manageability capabilities. Some of the capabilities may be generic, defined in MUWS and some may bear semantics specific to MOWS. For example, metrics available on Web services endpoint resources only may be captured in a UML model called EndpointMetrics which can be represented (rendered) into a WSDL interface description defined in a "urn:wsdm:webservice:endpoint:manageability:metrics" namespace. The UML model is an instance of the manageabilty capability concept and the WSDL interface description is an instance of the manageability interface concept. There could be other possible renditions of that UML model in other interface representations.

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
-- (631) 342-4325 .. 1 CA Plaza, Islandia, NY 11788

Long time ago I promised to provide words that go along with the MOWS concepts diagram. Here they are. Also attached is the diagram aligned with UML 2.0.

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Management of Web services (MOWS) is a particular case of Management using Web services (MUWS) in which a resource is an element of a Web Services Architecture. The Web services concepts, according to WSDL, are defined as follows. A service is an aggregate of endpoints each offering the service at an address and accessible according to a bidning. A service has a number of interfaces that are realized by all of its endpoints. Each interface descibes a set of named messages that could be exchanged and their format. Properly formatted messages could be sent to an endpoint's address in a way prescribed by the binding. A description (document, artifact) is composed of definitions of interfaces and services. A description may contain both or either of the definitions.

An IT resource may bear some functional (e.g. business) responsibilities such as, for example, placement of an order. That would constitute a functional capability with the distinct semantics of placing an order. A functional resource is a composition of such capabilties. An endpoint may provide access to the functional resource and in that case would offer those capabilities. Such endpoint is called a functional endpoint. To offer a capability an endpoint has to realize interfaces. An interface that represents a functional capability is called a functional interface. There is one to one match between capabilities and interfaces.

The MUWS concepts are defined very similarily to the functional concepts. There is a manageable resource that is a resource composed of a number of manageability capabilities each represented by a manageability interface.

Management of Web services starts from an endpoint resource which therefore becomes manageable resource called manageable endpoint. The reason the endpoint is the basis element is that (1) anything behind an endpoint is a concrete implementation (e.g. an application hosted in a container), and (2) anything that builds on endpoints is a logical construct and therefore understaning of it has to be inferred. Both of the above are currently out of scope of this specification.

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
-- (631) 342-4325 .. 1 CA Plaza, Islandia, NY 11788

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