WebLogic: The Definitive Guide

The MBean Architecture

Every WebLogic instance owns an MBean Server that hosts a number of MBeans. The MBean Server acts as a registry for the MBeans and provides services for accessing and manipulating MBeans running on the server. Because a WebLogic domain may be distributed across multiple machines with differing deployments and domain resources targeted to different servers, the MBean Server for each WebLogic instance will hold different types of MBeans. For instance, the runtime statistics for a JDBC connection pool on a server can be obtained only from an MBean running on that server. WebLogic makes a distinction between three different sets of MBeans:

Configuration MBeans

These expose attributes and operations for the configuration of a resource.

Runtime MBeans

These provide information about the runtime state of a resource.

Security MBeans

These reflect the SSPIs, providing direct access to the configuration of WebLogic’s security framework.

To fully understand the MBean architecture as implemented in WebLogic, you need to understand the different types of MBeans and how WebLogic distributes these MBeans across MBean Servers within a domain.

Configuration MBeans

A Configuration MBean holds the configuration for a managed resource or service within a WebLogic domain. WebLogic captures the configuration settings for all kinds of domain resources and services: web servers, clusters, JDBC connection pools, J2EE components (EJBs, web applications, resource adapters), JMS destinations, ...