[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: [OMod] William's AI: endpoint -> service
Here is some text on mapping endpoints to services to fulfill my action item... William A Web service endpoint is defined as the implementation of a WSDL 1.1 portType with a given WSDL 1.1 binding at a dereferencable URL. In a WSDL 1.1 document, it corresponds to a port element. There is no guarantee that only one endpoint corresponds to a given URL. Nevertheless, the notion of endpoint is relatively unambiguous. WSDL 1.1 defines a service element as a collection of port elements. There is no requirement that these ports have anything in common in terms of portTypes, bindings or endpoint URLs (the current draft of WSDL 2.0 specification requires that all ports in a service implement the same interface - the new name for portType). Therefore, WSDL 1.1 defines a Web service as any collection of endpoints that one chooses to group together in a service WSDL 1.1 element. The same set of endpoints can be grouped at the same time in many permutations of services by WSDL authors. In addition, other specifications can claim to define Web services, such as UDDI, that do not use the same mechanism. Implementing management at the Web service level therefore offers challenges in terms of identifying services. It also offers implementation challenges, for example if all the endpoints in a service are not implemented in the same environment (e.g. one endpoint inside the firewall and one endpoint outside of the firewall). Also, in many cases managers want to manage Web services at the granularity level of the endpoint: they need to know when one endpoint goes down and how many messages a specific endpoint has processed for example. At the same time, there are many cases where the manager wants to think at the Web service level and doesn't care about the endpoint. For example, a business manager using a business dashboard doesn't care whether the purchase orders arrive via the HTTP or the SMTP binding of the purchase service, or whether they arrive via the US server or its European mirror. In recognition of these requirements, the WSDM MOWS specification defines endpoints as the base building block for managing Web services. It also ensures that information is available for the manager to reconstruct the service-level view that some users require. This includes allowing the manager to request from the endpoint a list of WSDL documents that the endpoint knows of (to identify services that this endpoint is part of). It also includes allowing endpoints to establish relationships linking them as part of the same service. The presence of a collection mechanism will also allow a manager to access a set of endpoints (representing a service) as one entity. Finally, the MOWS specification will identify in a non-normative way capabilities of a service and how they can be derived from the capabilities of the endpoints that compose them.
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]