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orbd - Unix, Linux Command
NAMEorbd - The Object Request Broker Daemon
orbd is used to enable clients to transparently locate and invoke persistent objects on servers in the CORBA environment.
SYNOPSISorbd [ options ]
DESCRIPTIONThe Server Manager included with the orbd tool is used to enable clients to transparently locate and invoke persistent objects on server in the CORBA environment. The persistent servers, while publishing the persistent object references in the Naming Service, include the port number of the ORBD in the object reference instead of the port number of the Server. The inclusion of ORBD port number in the object reference for persistent object references has the following advantages:
|o The object reference in the Naming Service remains|
|independent of the server life cycle. For example, the object reference could be published by the server in the Naming Service when it is first installed, and then independent of how many times the server is started or shutdown, the ORBD will always return the correct object reference to the invoking client.|
|o The client needs to lookup the object reference in|
|the Naming Service only once, and can keep re-using this reference independent of the chanes introduced due to server life cycle.|
|Specifies the port on which the name server should be started. Once started, orbd will listen for incoming requests on this port. Note that when using Solaris software, you must become root to start a process on a port under 1024. For this reason, we recommend that you use a port number greater than or equal to 1024. (required)|
|Specifies the activation port where the ORBD should be started. The default value for this port is 1049. This port number is added to the port field of the persistent Interoperable Object References (IOR). (optional)|
|Specifies the base where the ORBD persistent storage directory orb.db is created. If this option is not specified, the default value is "./orb.db". (optional)|
|Specifies how often the daemon thread checks for the health of registered servers. ORBD polls process health every milliseconds. The default value is 1,000 ms (or 1 second). The value specified for milliseconds must be a valid integer.|
|Specifies how long the ServerManager waits before sending a location forward exception after the server is restarted. ORBD waits for milliseconds before raising a location forward exception. The default value is 1,000 ms (or 1 second). The value specified for milliseconds must be a valid integer.|
|Pass option to the Java virtual machine, where option is one of the options described on the man page for the java application launcher, java(1). For example, -J-Xms48m sets the startup memory to 48 megabytes. It is a common convention for -J to pass options to the underlying virtual machine.|
Starting and Stopping the Name ServiceA Naming Service is a CORBA service that allows CORBA objects to be named by means of binding a name to an object reference. The name binding may be stored in the naming service, and a client may supply the name to obtain the desired object reference.
Prior to running a client or a server, you will start ORBD. ORBD includes a persistent Naming Service and a transient Naming Service, both of which are an implementation of the COS Naming Service.
|o The Persistent Naming Service provides persistence|
|for naming contexts. This means that this information is persistent across service shutdowns and startups, and is recoverable in the event of a service failure. If ORBD is restarted, the Persistent Naming Service will restore the naming context graph, so that the binding of all clients and servers names remains intact (persistent).|
|o For backward compatibility, tnameserv, a|
|Transient Naming Service shipped with older versions of the JDK, is also included in this release of J2SE. A transient naming service retains naming contexts as long as it is running. If there is a service interruption, the naming context graph is lost.|
TO start orbd from a UNIX command shell, enterL
orbd -ORBInitialPort 1050&
From an MS-DOS system prompt (Windows), enter:
start orbd -ORBInitialPort 1050
Now that ORBD is running, you can run your server and client applications. When running the client and server applications, they must be made aware of the port number (and machine name, if applicable) where the Naming Service is running. One way to do this is to add the following code to your application:
Properties props = new Properties(); props.put("org.omg.CORBA.ORBInitialPort", "1050"); props.put("org.omg.CORBA.ORBInitialHost", "MyHost"); ORB orb = ORB.init(args, props);
In this example, the Naming Service is running on port 1050 on host "MyHost". Another way is to specify the port number and/or machine name when running the server or client application from the command line. For example, you would start your "HelloApplication" with the following command line:
java HelloApplication -ORBInitialPort 1050 -ORBInitialHost MyHost
To stop the naming service, use the relevant operating system command, such as pkill orbd on Solaris, or Ctrl+C in the DOS window in which orbd is running. Note that names registered with the naming service may disappear when the service is terminated if the naming service is transient. The Java IDL naming service will run until it is explicitly stopped.
For more information on the Naming Service included with ORBD, see Naming Service.
Server ManagerTo access ORBDs Server Manager and run a persistent server, the server must be started using servertool, which is a command-line interface for application programmers to register, unregister, startup, and shutdown a persistent server. When a server is started using servertool, it must be started on the same host and port on which orbd is executing. If the server is run on a different port, the information stored in the database for local contexts will be invalid and the service will not work properly.
Server Manager: an ExampleUsing the sample tutorial for our demonstration, you would run the idlj compiler and javac compiler as shown in the tutorial. To run the Server Manager, follow these steps for running the application:
|1. Start orbd.|
To start orbd from a UNIX command shell, enter:
|orbd -ORBInitialPort 1050|
From an MS-DOS system prompt (Windows), enter:
|start orbd -ORBInitialPort 1050|
|2. Start the servertool:|
To start the Hello server, enter:
|servertool -ORBInitialPort 1050|
3.Start the Hello server from the servertool prompt:
4. Run the client application from another terminal window or prompt:
|java HelloClient -ORBInitialPort 1050 -ORBInitialHost localhost|
Specify the name server (orbd) port as done in the previous step, for example, -ORBInitialPort 1050.
|5. When you have finished experimenting with|
|the Server Manager, be sure to shut down or kill the name server (orbd) and servertool.|
To shut down the servertool, type quit and press the Enter key on the keyboard.