Communicating with JMX agents - JMX in Action - page 213

In addition, you must use the rmic compiler to generate stubs for the
JINIConnectorImpl class.

Set up the Jini environment. Doing so involves starting an HTTP server,
starting the Java activation daemon ( rmid ), and starting a Jini lookup ser-
vice. Read the Jini documentation to see how to perform these steps.

2

Start the JMX agent. You will need to start the agent with a policy file indi-
cated by the -Djava.security.policy property in the java command.

3

Run the client class ( JINIConnectorClient ). Doing so will invoke the
class's main() method. The method will use the JINIConnector to find the
JMX agent, get its MBean count, and create a new HelloWorld MBean on
the agent.

4

The best way to see the results of this simple test is to open your browser (while
the agent is still running) to the location http://localhost:9092 (assuming you are
on the same machine as the agent). You should see all three adapter/connector
MBeans ( HTML , RMI , and Jini) as well as a new HelloWorld MBean.

9.4 J MX and SNMP

A large number of vendors have distributed many devices with SNMP manage-
ment capabilities. It would be ideal if you could use this existing management
base with new applications and systems you are building today. For example, a
networking application could acquire knowledge of the health of the hardware it
requires before making routing decisions. For such situations, it makes sense to
use the SNMP technology already in place. Fortunately, due to the JMX architec-
ture, your JMX agents can expose MBeans using an SNMP adapter. This section
will review SNMP and provide information about using JMX with SNMP .

9.4.1 What is SNMP?

SNMP is a monitoring standard that has been in wide use for several years.
( SNMP stands for Simple Network Management Protocol, but most developers
might argue that it is not that simple.) Two versions of SNMP (v1 and v2) already
exist, and a third version is being defined by the Internet Engineering Task
Fo rc e ( IETF ).
In an SNMP system, there are managed devices such as routers, hubs, comput-
ers, operating systems, and even applications. Basically, any device or system
that can expose information about itself can become a managed device. SNMP
agents exist to convert requests or messages from the SNMP protocol to a device.