The Community OpenORB Naming Services

The OpenORB Interoperable Naming Service (INS) is a fully compliant implementation of the Interoperable Naming Service specified by O.M.G. The persistence of this naming service is managed by the OpenORB Persistent State Service. That allows you to persist objects into a file or a database. The main purpose of the Naming Service is to organize CORBA Objects into a naming graph. Each object in the naming graph is called a name binding. A name binding is always defined relative to a naming context. A naming context is a node that contains a set of name bindings in which each name is unique.

To use the Transient Naming Service, you need the OpenORB kernel; to use the Interoperable Naming Service, you need the OpenORB kernel and the OpenORB Persistent State Service. You can find both modules at http://openorb.sourceforge.net in the Download section.

The Interoperable Naming Service distribution contains an Ant script. Several dependances are required: The OpenORB kernel distribution , the Persistent State Service distribution and the Transaction Service distribution. You need to add to your classpath those distributions (this includes openorb-{version}.jar, openorb_tools-{version}.jar, openorb_pss-{version}.jar and openorb_ots-{version}.jar files). We advise you to use the build.bat (for windows) or build.sh (for unix).

Then, to compile the OpenORB Interoperable Naming Service, enter the following command from the command line from the root directory NamingService that you got when downloading the service:

build or sh build.sh

The initial reference of the Naming Service is required to initialize the service. You may modify the OpenORB.xml file to configure the initial reference:

        <module name="InitRef">
          <property name="NameService"
            value="corbaloc://1.2@host:port/NameService" />
        </module>
      

The OpenORB.xml, as shipped, contains this text definining the initial reference. The value attribute holds the location of the Name Service, and may be specified by a corbaloc, corbaname, or IOR. To use the corbaloc above, replace the literals host and port with the appropriate values.

To get the Naming Service initial reference, use the resolve_initial_reference method to look up "NameService".

To complete the configuration, we have to replace the embedded configuration of OpenORB by the new one. The way to do that depends on the distribution that you are currently using: source code or pre-built distribution. The following paragraphs describes how to proceed for each kind of distribution.

In that case, an Ant target is provided to replace the embedded configuration file. From the command line, run:

          build config
        

In that case, the config directory of OpenORB contains a script named setConfig (setConfig.bat for Windows and setConfig.sh for Unix). We have just to start this script to replace the embedded configuration file.

Here is the command line that will start the Interoperable Naming Service:

        java org.openorb.ins.Server -default ( or -ORBPort=portNumber ) 
      

When you start the OpenORB Naming Service, you can

If you start the OpenORB Naming Service with a specific port number, you have to specify it in the initial reference of the NameService configuration in your OpenORB.xml file.

        <property name="NameService"
            value="corbaloc://1.2@host:port/NameService" />
      

Notice that you can persist your data by specifying the flag -file or -database when launching the Naming Service. We remind you that such persistence is managed by the OpenORB Persistent State Service. That means you must have configured your OpenORB.xml file: you must have at least a module mamed "pss". For more information about the installation and configuration of the Persistent State Service, refer to the documentation that is delivered with the distribution of that service.

You may want to shutdown the Naming Service from a distant host or from an application.

The OpenORB Naming Service allows you to do that by specifying a -shutdown flag when launching the Naming Service. Using this flag, if you invoke the destroy method on the root node (this is not permitted otherwise), you will shutdown the Naming Service.

The CosNaming module is a set of interfaces that define the Naming Service. It contains three interfaces:

The Naming Context interface provides a NameComponent description and a Binding description. A NameComponent consists of two attributes: the identifier attribute, id and the kind attribute, kind. A Binding contains a Name and a BindingType.

The Naming Service supports four operations to create Bindings:

This interface also provides operations for resolving names, unbinding names, deleting contexts and listing a Naming Context.

This interface has been introduced for the Interoperable Name Service. This interface extends NamingContext and provides several new methods to manage CORBA URL.

The BindingIterator interface allows a client to iterate through the bindings using the next_one or next_n operations.

For more information of how to use those interfaces, refer to the Api documentation of this Naming Service.

When you run a build on the Naming Service module, the examples-{version}.jar is created in the dist directory.

To launch the example, you just have to launch the Client class after the Naming Service itself.

          java org.openorb.ins.examples.Client
        

When launching the example, you will see a menu that allows you to:

            0- Quit the example application
            1- Bind a new Naming Context
            2- Rebind a Naming Context
            3- Bind a Naming Object
            4- Rebind a Naming Object
            5- Resolve a Binding
            6- Unbind a Binding
            7- List all the Bindings
          

All those actions will be applied on the initial context of the Naming Service.

This example was developed to show how easily you can develop your applications using this Interoperable Naming Service.

However, we give you the possibility to explore and execute such actions in a graphical interface you can plug into our OpenORB Management Board.

For more information about the Interoperable Naming Service Plugin, see the next chapter.

The INS Plugin requires the ManagementBoard distribution. For more information concerning that module, refer to the documentation which is delivered with the ManagementBoard packaging.

You can download the ManagementBoard module on the OpenORB web site. You need to put the openorb_board-{version}.jar file in your CLASSPATH environment variable.

Once you have downloaded that module, you can build the INS Plugin application with the Ant tool. From the NamingService directory, run build plugin or sh build.sh plugin to build the INS Plugin.

You will then find a insplugin-{version}.jar file in the dist directory. Add it to your CLASSPATH environment variable.

You also have to update the board.xml file provided by the ManagementBoard to specify that you want to start the Board with the INS Plugin. When editing your OpenORB.xml file, add the following information in the board module.

        <property name="namingPluginClass"
            value="org.openorb.ins.plugin.Plugin"/>
        <property name="namingPluginPath"
            value="<PATH>/insplugin-{version}.jar"/>
        <property name="namingPluginHelp"
            value=""/>
      

For more information about such a configuration, refer to the ManagementBoard documentation.

After you have installed and configured the Management Board as explained above, you can now launch it by using this command line:

        java org.openorb.board.Board -ORBProfile=xxx
      

where xxx is the board profile that imports the board module.

Here is the graphical interface from which you can display and use the Naming Service.

To connect a specific Naming Service, click on the Connect... button on this interface. A dialog box will appear enabling you to specify where the Naming Service is running.

You have two possibilities. The first one is to use initial references. In this case, you do not need to fill in the text fields below. The connection will be done reading the OpenORB configuration file. Otherwise, you can use corbaloc reference. In that case, you have to specify the host and the port number of the system where the Naming Service is running.

This plugin allows you to execute all the operations provided by the Naming Service. You can bind, rebind, bind a Naming Context or a Naming Object and explore all Bindings in a hierarchical way (on a graphical tree representation)