Saturday, March 24, 2012

Java Management Extensions and Weblogic Server MBeans


The best part I like about Java Management Extensions (JMX) framework is that it allows developers of applications, services, or devices to make their products manageable in a standard way without having to understand or invest in complex management systems.

JMX has been around as a core JEE API for a long time and is the foundation for everything you can do to manage the Oracle Weblogic Server. The JMX architecture in the context of Weblogic Server as I see it is shown in figure below:

Application components designed with their management interface in mind can typically be written as MBeans. WLS MBeans are 3 types - Domain, Server and Application level MBeans. You can instrument your applications deployed to WLS by providing one or more management beans. For example, the DomainRuntimeMBean provides a federated view of all of the running JVMs in a Weblogic administrative domain. All Weblogic Server MBeans can be organized into one of the following general types - Runtime MBeans or Configuration MBeans based on whether the MBean monitors the runtime state of a server or configures servers and JMX manageable resources.

WLS MBean Server acts as a container for MBeans. The MBean servers available in a Weblogic domain are:
  1. Runtime MBeanServer: is the MBeanServer available from any Weblogic process, and contains both Weblogic and user MBeans. Each server in the domain hosts an instance of this MBean server.
  2. Domain MBeanServer: This MBeanServer provides federated access to MBeans for domain-wide services. Collocated with the WLS domain admin server process, this server  also acts as a single point of access for MBeans that reside on Managed Servers.  So, as long as a managed server is up, its MBeans can be accessed through the "Domain Runtime" MBeanServer.
  3. Edit MBeanServer: Collocated with the WLS domain admin server process, it provides access to pending configuration MBeans and operations that control the configuration of a Weblogic Server domain. No application MBeans can be registered in this MBeanServer. 
The JMX API enables to perform remote management of resources by using JMX technology-based connectors (JMX connectors). Adaptors and connectors make all MBean server operations available to a remote management application. Fusion Applications Control (or commonly known as EM Console) is the primary administration management interface. Developers can programmatically monitor Weblogic Server by using the JMX interface directly in a Java program or by writing scripts using a tool such as WLST.

Here is a good blog article on managing WLS using Jconsole: http://blogs.oracle.com/WebLogicServer/entry/managing_weblogic_servers_with

Please refer the Oracle Weblogic Server documentation for the latest on WLS-MBeans.