2.2 The MBean Server

The MBean server is a registry for JMX manageable resources, which it exposes to management requests. The MBean server provides a protocol-independent and information model independent framework with services for manipulating JMX manageable resources.

If you choose to register a resource's MBean with the MBean server, the MBean becomes visible to management applications and is exposed to management requests. The MBean server makes no distinction between the types of MBeans. Standard, dynamic, model and open MBeans are managed in exactly the same manner.

You can register objects in the MBean server through the following.

• The other objects in the agent application.

• A remote management application, through a connector or a protocol adaptor.

The MBean server responds to the following management requests on registered MBeans.

• Listing and filtering MBeans by their symbolic name

• Discovery and publication of the management interface of MBeans

• Accessing MBean attributes for reading and writing

• Invoking operations defined in the management interface of MBeans

• Registering and unregistering listeners for MBean notifications

The MBean server never provides the programmatic reference of its MBeans. The MBean server treats an MBean as an abstraction of a management entity, not as a programmatic object. All management requests are handled by the MBean server, which dispatches them to the appropriate MBean, thus ensuring the coherence in an agent.

An MBean is identified by a unique symbolic name, that is called its object name. The object name can be assigned either by the entity registering the MBean or by the MBean itself, if its implementation has been designed to provide one. Managers give this object name to designate the target of their management requests. Unless specified otherwise, object names are local to a specific MBean server. You can however make object names global if you want to implement the cascading service (see 2.5.5 Cascading).

It is possible to have multiple MBean servers within the same Java virtual machine, with each MBean server managing a set of resources.