The MBean server delegate is an MBean that is automatically instantiated and registered by the MBean server when it is created. It provides information about the version of the Java Dynamic Management Kit (Java DMK) that is running, and it represents the MBean server when sending notifications.
Notifications are events sent by MBeans. They are covered in detail in Chapter 8, Notification Mechanism. Because the MBean server instance is not an MBean object, it relies on its delegate MBean to send notifications. The MBean server delegate sends notifications to inform interested listeners about such events as MBean registrations and unregistrations.
The exposed attributes of the delegate MBean provide vendor and version information about the MBean server. This can let a remote management application know which agent version is running and which version of the Java runtime environment it is using. The delegate MBean also provides a unique identification string for its MBean server.