Examples : JMX : MLet

Example on MLet

Contents:

Introduction
Overview
Getting Started

Compilation
Running
Testing

Introduction

This is a simple example to illustrate the use of dynamic loading of management applet (MLet).
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Overview

Let us say MBeans present at a remote place wants to get registered/managed with the local Multi-Protocol (JMX) server. The javax.management.loading.MLet mbean allows us to achieve this.
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Getting Started :

Source files

The main source file is,

MLetAgent.java

In the folder "test" we have the source for the sample mbeans namely,

MySample1.java
MySample1MBean.java
MySample2.java
MySample2MBean.java

The main file MLetAgent.java has 3 adaptors (HTTP/RMI/CORBA) along with MLet MBean, registered with the MBeanServer.

Consider, MBeans in local Multi-Protocol MBeanServer as,

com.adventnet.adaptors.http.HttpAdaptor
com.adventnet.adaptors.rmi.RMIAdaptor
com.adventnet.adaptors.corba.CorbaAdaptor
javax.management.loading.MLet

Suppose, at remote host the following MBean is present

myPackage.MySample in a jar file(lets say MySample.jar)

To get these MBeans registered & managed by the local Multi-Protocol server, then we have to define a mlet text file accordingly. For instance, in this example the sample-mlet.txt file describes to download the MySample.jar which has the mbeans from host="localhost" & port="8080".

Compilation

To compile the source files go to WebNMS/JavaAgent/examples/jmx/mlet directory in the command prompt and type,

compile *.java [Windows]
sh compile sh *.java [Linux/Solaris]

This will compile the source files in the respective directory.

Running the Agent

To start the agent go to WebNMS/JavaAgent/examples/jmx/mlet directory in the command prompt and,

1. Run the startServer.bat/sh to start the remote web-server for downloading the mlet.(starts at port 8080, as specified in WebNMS/JavaAgent/etc/MletServer.xml file.)

2. Also run the run.bat or run.sh.

          By default,
                  (a) RMI registry service will be started at port 1099
                  (b) HTML Adaptor will be started at port 8030.

Testing

1. Use any webbrowser to connect to the Multi-Protocol (JMX) server (through HTML adaptor) by specifying the URL as http://localhost:8030

2. Use MBean browser to access the data through RMI/CORBA/HTTP ( start MBean browser using MBeanBrowser.bat/MBeanBrowser.sh in WebNMS/JavaAgent/bin directoy)

3. Now to register the remote mbeans, select the MLet mbean in MBean/WebBrowser

             (a) invoke the method "void getMBeansFromURL(java.lang.String)" with parameter as "http://localhost:8080/sample-mlet.txt"
             (b) now the mbean MLetGroup:description=myPackage.MySample gets registered and updated in the main mbeans list view of the browser as specified in the mlet file.
             (c) Now the remote mbeans are configurable through the adaptors
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