Web Services Distributed Management support in the application server
The Web Services Distributed Management (WSDM) support for a Web service in WebSphere Application Server runs within an application server that has exposed management functions.
In the application server implementation of WSDM, a WSDM application is packaged as a Java Platform, Enterprise Edition (Java EE) Enterprise archive (EAR) file. The EAR file is deployed as an application server system application.
Important: WSDM is a system application and it is disabled by default when the product is installed. We must first enable WSDM before we can use it to manage the product resources. Use scripting to enable WSDM.
WSDM support for the product consists of two parts:
- WSDM runtime environment and support
- WSDM resource model and service implementation
The WSDM runtime environment provides fundamental capabilities for the manageable resources. The WSDM runtime environment interacts with the underlying web services platform and the WSDM resources to service the requests and responses. There are multiple specifications that the WSDM runtime environment uses in order to provide the WSDM functions, namely WS-Addressing, WS-ResourceFramework, and WS-Notification. For each request, the WSDM runtime environment routes the request to the appropriate resource service implementation based on the endpoint reference, (EPR). The EPR is defined by the WS-Addressing specification. Each EPR contains target address, runtime specific data and reference properties to uniquely identify an instance of a WSDM resource. After the resource service implementation returns a response, the WSDM runtime environment wraps the response into an appropriate SOAP message format specified in the Management Using Web Services (MUWS) specification and returns the response back to the requester. The application server leverages Apache Muse 2.0 to provide the runtime support for WSDM. The Apache MUSE 2.0 provides both the development tool and the WSDM runtime environment.
The WSDM resource model for the application server identifies the elements of the product that are managed resources and further defines the specific properties, operations, and notifications that are managed resources support. The resource model defines the interfaces to interact with the resources and administrative functions in the product. The resource model includes appropriate capabilities defined in the two WSDM specifications, Management Using Web Services (MUWS) and Management of Web Services (MOWS). What this means is that the implementation is a mapping of the WSDM specification interfaces onto the product administration and programming interfaces. The implementation does not introduce new functions into the product, but rather, an alternative interface for accessing existing administration and programming functions in the product. In addition, the resource model defines specific capabilities to provide additional manageability functions. Each of the capabilities defines a set of properties, operations, and events for managed resources in an autonomically managed system. Each resource is associated with a Web Services Description Language (WSDL) file containing the definition of its manageability capabilities.
The implementation is attached to the WSSecurity default policy set and runs the administrative operations from the client user identity. This user identity must have privileges to perform any administrative action. It is the role of the autonomic computing (AC) manager that makes requests for the WSDM implementation to ensure that the user of that manager has appropriate authorization to perform administration and any other functions exposed by the AC manager.
The benefit of WSDM support in the application server is that the product can participate in multiple product management solutions in a standard way. By exposing the product management functions through a standard web services interoperable interface, we can combine the application server with large management systems based on the WSDM specification.
Related:
Web Services Distributed Management Enable WSDM Making deployed web services applications available to clients Configure application and system policy sets for web services Secure requests to the trust service using system policy sets Web Services Distributed Management manageability capabilities for WAS resource types Web Services Distributed Management in a stand-alone application server instance Web Services Distributed Management in a WAS ND cell Programming model APIs and specifications