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JMX and MBeans

The first thing was to understand a bit more about what jmxetric does. But before that we have to lay the foundation first, let’s talk about JMX and MBean.

JMX is a technology that lets you monitor resources easily

JMX stands for Java Management Extension. Resources can be applications, devices, services, etc. By monitoring, it means that you can 1. consult and change configuration, 2. view statistics of the application 3. be notified of changes and/or erros

How can you make use of this JMX technology? You follow the patterns and interfaces defined in this specification. And one of it is MBean

MBean, or Managed Bean

A MBean, is a Java object that is associated with a resource that you want to monitor. All MBeans expose an interface that has 1. set of readable and/or writable attributes 2. set of invokable operations 3. self-description

You can make an MBean by making a Java interface called FooMBean, and a class Foo that implements that interface.

You can manage MBeans using a JMX agent

It’s strange that you still need to manage a managed bean, but that’s just how it goes. A JMX agent is the manager of all these MBeans and the resources instrumented by the MBeans. The agent consists of a MBean server, which is where MBeans are registered. I think of the MBean server as a manager that overseas the registered MBeans.

How does jmxetric fit in here?

The role of jmxetric is then to pool these MBeans, and pass on the attributes to Ganglia.

References

Oracle’s tutorial trail on JMX Oracle’s tutorial on MBeans