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Instrumentation Level


A manageable resource can be a "Servlet, JSP, EJB, Java class, Java method, Java variable, or any legacy non-Java applications". A JMX manageable resource is developed in Java, or at least offers a Java wrapper, and has been instrumented so that it can be managed by JMX-compliant applications.

The instrumentation of a manageable resource is provided by one or more Managed Beans, or MBeans. The instrumentation level provides a specification for defining the MBeans. In addition, the instrumentation level also specifies a notification mechanism which allows MBeans to generate and propogate notification events to components of other levels. (Notification model in JMX is explained in later sections.)

What is an MBean ?


Managed Bean (MBean) represents a manageable resource. An MBean is a Java object, which follows some semantics. The fields or properties of this Java object are called attributes. The methods of this Java object are called operations.

 Definition of MBean 

MBeans are the JMX objects which exposes the management information in the form of attributes and operations.

 Semantics for an MBean 

 Types of MBeans 

MBeans can be classified into four types. They are
  1. Standard MBean
  2. Dynamic MBean
  3. Model MBean
  4. Open MBean
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JMX Architecture Standard MBean