Extending the WebSphere Application Server administrative system with custom MBeans

You can extend the WebSphere Application Server administration system by supplying and registering new JMX MBeans (see JMX 1.x Specification for details) in one of the WebSphere processes.

Overview

Procedure

1. Create custom JMX MBeans.

   You have some alternatives to select from, when creating MBeans to extend the WebSphere administrative system. You can use any existing JMX MBean from another application. You can register any MBean that you tested in a JMX MBean server outside of the WebSphere Application Server environment in a WebSphere Application Server process, including standard MBeans, dynamic MBeans, open MBeans, and model MBeans.

   In addition to any existing JMX MBeans, and ones that were written and tested outside of the WebSphere Application Server environment, you can use the special distributed extensions provided by WebSphere and create a WebSphere ExtensionMBean provider. This alternative provides better integration with all of the distributed functions of the WebSphere administrative system. An ExtensionMBean provider implies that you supply an XML file that contains an MBean Descriptor based on the DTD shipped with the WebSphere Application Server. This descriptor tells the WebSphere system all of the attributes, operations, and notifications that your MBean supports. With this information, the WebSphere system can route remote requests to your MBean and register remote Listeners to receive your MBean event notifications.

   All of the internal WebSphere MBeans follow the Model MBean pattern. Pure Java classes supply the real logic for management functions, and the WebSphere MBeanFactory class reads the description of these functions from the XML MBean Descriptor and creates an instance of a ModelMBean that matches the descriptor. This ModelMBean instance is bound to your Java classes and registered with the MBeanServer running in the same process as your classes. Your Java code now becomes callable from any WebSphere Application Server administrative client through the ModelMBean created and registered to represent it.

2. Optionally define an explicit MBean security policy.

   If you do not define an MBean security policy, WebSphere Application Server uses the default security policy.

3. Register the new MBeans. There are various ways to register your MBean.

   You can register your MBean with the WebSphere Application Server administrative service. You can register your MBean with the MBeanServer in a WebSphere Application Server process. The following list describes the available options in order of preference:

   • Go through the MBeanFactory class. If you want the greatest possible integration with the WebSphere Application Server system, then use the MBeanFactory class to manage the life cycle of your MBean through the activateMBean and deactivateMBean methods of the MBeanFactory class. Use these methods, by supplying a subclass of the RuntimeCollaborator abstract superclass and an XML MBean descriptor file. Using this approach, you supply a pure Java class that implements the management interface defined in the MBean descriptor. The MBeanFactory class creates the actual ModelMBean and registers it with the WebSphere Application Server administrative system on your behalf.

     This option is recommended for registering model MBeans.

   • Use the JMXManageable and CustomService interface. You can make the process of integrating with WebSphere administration even easier by implementing a CustomService interface that also implements the JMXManageable interface. Using this approach, you can avoid supplying the RuntimeCollaborator. When your CustomService interface is initialized, the WebSphere MBeanFactory class reads your XML MBean descriptor file and creates, binds, and registers an MBean to your CustomService interface automatically. After the shutdown method of your CustomService is called, the WebSphere Application Server system automatically deactivates your MBean.

   • Go through the AdminService interface. You can call the registerMBean() method on the AdminService interface and the invocation is delegated to the underlying MBeanServer for the process, after appropriate security checks. You can obtain a reference to the AdminService using the getAdminService() method of the AdminServiceFactory class.

     This option is recommended for registering standard, dynamic, and open MBeans. Implement the UserCollaborator class to use the MBeans and to provide a consistent level of support for them across distributed and z/OS platforms.

   • Get MBeanServer instances directly. You can get a direct reference to the JMX MBeanServer instance running in any WebSphere Application Server process, by calling the getMBeanServer() method of the MBeanFactory class. You get a reference to the MBeanFactory class by calling the getMBeanFactory() method of the AdminService interface.

     When a custom MBean is registered directly with the MBean server, the MBean object name is enhanced with the cell, node and process name keys by default. This registration allows the MBean to participate in the distributed features of the WebSphere Application Server administrative system. You can turn off the default behavior by setting the com.ibm.websphere.mbeans.disableRouting custom property.

Results