MOSGi enables the remote management of OSGi-compatible service gateways, using JMX. The framework is a reference architecture for end-to-end gateway management. It provides the following features:

• relies on JMX management infrastructure (IP-based management),
• provides two JMX agents: the standard Java 1.5 agent and a specific Java 1.4 lightweight embedded agent (MX4J agent deviation),
• provides a way to deploy various probes on remote gateways,
• provides a management console,
• the graphical part of a probe (management console part) can be dynamically plugged in the management console and is dynamically downloaded.

Very fast QuickStart Guide

Go into $FELIX_HOME/trunk/mosgi.doc and read Readme.txt.

General architecture

The overall architecture is presented in the following picture :

How it works

Managed OSGi gateways can install JMX probes from various repositories. A JMX probe is a standard OSGi bundle that registers an test component in the managed gateway's JMX agent.

The management console (running in a standard OSGi framework) is connected to each gateway through the JMX remoting protocol. When it connects for the first time to a managed gateway, it asks for probes that are installed (i.e. all MBeans registered in the TabUI JMX domain). Then, for each MBean found, the management console asks for its graphical representation through a call to our standard API (component getUI() call). This call redirects to a bundle in the GUI probe repository that is installed by the management console. So the management console discovers at run-time the user interface it should use to
supervise a specific remote gateway.

Here is a description of different bundles that should be installed on both parts of the infrastructure (managed OSGi gateway and Management console).

A managed OSGi gateway must host the following bundles :

• JMX-MX4J Agent Service: provides a JMX agent. Either through a wrapper to jdk1.5 standard agent or through using a specific lightweight inner agent1 (originate from mx4j project). This agent service also declares a standard MBeanServer service interface..

• JMX rmiregistry: wraps RMI registry life cycle. It's used by the JMX remoting infrastructure to register

• JMX RMI connector: wraps a standard JMX remoting RMI connector

• Remote Logger: notifies log informations

A JMX Console is an OSGi framework also (for simplicity) which should host two bundles :

• JMX Console: the graphical framework that will host graphical plugins
• jmxconsole common tabs: tabs that are common to all gateways. For the moment it only concerns a tab that shows remote notification (it works whith remote logger)

OSGi/JMX MBean registration

MOSGi installs JMX-MX4J agent at the gateways level. Any one can register an MBean to the JMX agent. The registration can be made in two ways. The direct code and the white board pattern.

• In the direct code, one can register an MBean to the agent through the standard service interface : javax.management.MBeanServer

For instance :

org.osgi.framework.ServiceReference sr = context.getServiceReference(javax.management.MBeanServer.class.getName());
javax.management.MBeanServer mbs=(javax.management.MBeanServer)context.getService(sr);
mbs.registerMBean(new MBeanImpl(), new ObjectName("Foo:FooName");

Exemple of such code is uses in mosgi.managedelements.bundlesprobes code in felix repository

• In the whiteboard pattern, one can register an MBean through registering its interface to the framework as a service. If the interface name ends with MBean or if the interface is javax.management.DynamicMBean, the agent will automatically register the implementation as a standard MBean. The objectName of the MBean can either be defined at registration time with the org.apache.felix.mosgi.jmx.agent.Constants.OBJECTNAME property name or automatically build through introspection.

For instance :

java.util.Properties prop=new java.util.Properties();
prop.add( org.apache.felix.mosgi.jmx.agent.Constants.OBJECTNAME, "Foo:FooName");
context.registerService(test.FooMBean.class.getName(), new test.Foo());