Administration 

Purpose

The administration of the J2EE Engine is based on the Java™ Management Extension (JMX™). The JMX™ specification enables arbitrary Java resources to be managed in a standard way. So that they are manageable, these Java resources have to provide a management interface and register an object that implements it – called an MBean – in a MBean Server. The MBean server acts like a container for the MBeans and provides different types of management applications that can use MBeans to manage their Java resources. To connect to the MBean Server the management applications may use different approaches – either using well-known protocols (such as HTTP) wrapped by an appropriate adaptor that translates the operations into a representation in the given protocol, or using connectors that provide the same interface to the management applications as the MBean Server, and use a proprietary protocol.

Features

The JMX infrastructure distinguishes three different layers:

·        instrumentation level – consists of the managed Java resources and their MBeans;

·        agent level – consists of the MBean Server;

·        distributed services level – includes the management applications, the adaptors, and the connectors;

In the J2EE Engine the agent level is included as an external library – com_sap_pj_jmx.jar. There is also a JMX Adapter Service that provides some of the functionality from the distributed services level. It creates an instance of the MBean Server on each element in the cluster and provides local and cluster connections to all of them. In this way, a user of the JMX infrastructure may work with distributed MBean servers transparently, that is, from user’s perspective there is only one MBean Server that contains all MBeans registered clusterwide. To receive JMX notifications clusterwide there is a small service called JMX Notification Service, which is tightly connected to the JMX Adapter Service. The graphic below shows the interactions between the J2EE Engine administration components:

J2EE Engine Administration

 

This section describes the administration specifics and provides a short description of the MBean Server implementation and the JMX services. It also clarifies the roles that the Administration Adapter and Basic Administration services play in the overall process of management. For more information, see JMX Service Interface and Administration Adapter Service.