SLP-Examples-JMX

• Introduction to the Service Location Protocol
• Deployment scenarios
• Examples
  • Code Example
  • Jetty6 Example
  • JMX Example
  • Attributes Example
  • OSGi Examples
• Why LiveTribe :: SLP does not implement RFC 2614
• Frequently Asked Questions

How to use SLP to advertise JMXConnectorServers

In this example, based on J2SE 5, you will see how SLP can simplify the task of connecting to a remote JMXConnectorServer from a client. We will expose the J2SE 5 platform MBeanServer using an RMI JMXConnectorServer, so that clients can use an RMI JMXConnector to connect to it.

The example shows the differences between a non-SLP environment where knowledge of the location of the services is needed, and an SLP environment, where SLP takes care of discovering the location of the services.

The non-SLP environment

In the usual environment there are 3 participants:

• The server host, that runs the MBeanServer and the JMXConnectorServer.
• The naming host, that runs the naming server; when using the RMIRegistry, the naming host and the server host coincide.
• The client host, that runs the JMXConnector and the client code.

The JMXConnectorServer is started with a JMXServiceURL similar to this one:

service:jmx:rmi:///jndi/rmi://naminghost/foo

where "foo" is the JNDI name under which the RMI stub is registered.

The client code must know the same JMXServiceURL, or otherwise it has no clue on how to connect to the server host. Potentially, the naming host could be any host in the network, and the server code may have registered the stub under any JNDI name, and the client may not know neither the naming host nor the JNDI name.
Often, this knowledge of the location of the services (in this case the JMX stub) is not known a priori, or it must be configured in the clients.

The SLP environment

In the SLP environment there are only 2 participants:

• The server host, that runs the MBeanServer and the JMXConnectorServer.
• The client host, that runs the JMXConnector and the client code.

There is no need of the naming host, nor of the RMIRegistry.

In the SLP environment, the JMXConnectorServer is started with a JMXServiceURL similar to this one:

service:jmx:rmi:///

After the JMXConnectorServer has been started, the JMXServiceURL is modified by the JMXConnectorServer, and becomes similar to this one:

service:jmx:rmi:///stub/<Base64 encoded stub>

Once the JMXConnectorServer has been started, an SLP ServiceAgent advertises the JMXServiceURL as a service. In this way, SLP UserAgents can find the advertised service and connect to it.

Below you can find examples of server and client code.