Resource management and JMX - JMX in Action - page 9

that building such an environment is difficult and can leave administrators with
many different tools in which to manage the system. As this topic will show, using
Java Management Extensions, you can build a management environment that's
less expensive and more flexible, in a shorter amount of time. JMX is a new
framework added to the Java language; it can provide a management solution
that covers the standards described in the previous section. JMX allows you to
encapsulate all your resources (hardware or software) with Java objects and
expose them in a distributed environment. In addition, JMX provides a mecha-
nism for easily mapping existing management protocols such as SNMP into its
own management structures.
Let's look at the management areas identified in the previous section and
how JMX can address them:
■ Platform health— As previously mentioned, using JMX , you can wrap non-
Java resources and hardware interfaces with Java objects in order to fit
them into a JMX management system. Using Java wrappers, you can inter-
face to your web and application servers and communicate with the hard-
ware driving your system.
■ Configuring resources and collecting application statistics— Using JMX , you can
directly expose the API of applications and services. In addition, you can
dynamically choose what parts of the API to expose. With a JMX manage-
ment tool, you can then invoke and query the API at any time. In fact, if
you know you will be using JMX ahead of time, you can build into your
application the simple JMX component that will expose it to the JMX man-
agement environment. However, you can use JMX to very quickly instru-
ment an application even if development is already completed.
■ Debug options— Debug options are configurable like any other application
or resource attribute. Once an interface is exposed through JMX , it can
be invoked.
■ Application performance— With JMX , you can easily monitor the system for
critical events. When an event is noticed, JMX can emit notifications to a
predefined listener process. Listeners can be configured to send pages,
write email messages, and so forth; the process is entirely customizable.

1.2.1 Benefits of using JMX

Using a Java-based solution such as JMX offers several benefits, some of which
are probably evident to you as a Java programmer. For example, Java is a porta-
ble language (write once run anywhere), so you can develop your application