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Distributed Installation Configuration

Multiple OpenFusion installations can be configured from a central host. This allows OpenFusion Services on different machines to share common configuration files and, if required, a common implementation repository.

The machines can be connected via a shared file system or by using a Web server running on the central host.

Note that the central configuration host and each remote machine must have a licensed OpenFusion installation.

The Central Configuration Host

The XML files used to configure the properties of each remote OpenFusion installation are all stored on the central configuration host under the domains directory (see The Object Hierarchy for details). The central host must therefore be configured to store details of each remote installation.

Each remote installation should be set up as a separate node in the Administration Manager Object Hierarchy on the central host. (See Adding Nodes.)

Each node should have the unique machine name of the remotely-managed computer.

Each remote machine displays the full Object Hierarchy from the central host, including all remote machine nodes and the localhost node, unless the Administration Manager is started with the -remote command-line option, for example:

% bin/manager -remote


The appearance of the localhost node could potentially cause confusion for remote users. It might be assumed that localhost refers to the remote machine, but it actually refers to the central host. To avoid the confusion, delete the localhost node from the central configuration host's Object Hierarchy and add a new node with the name of the host machine.

Add Services to each node and add Singletons and Java Objects to the Services, as described in Adding Singletons and Java Objects. The Singletons and Java Objects must exist as valid, licensed objects on the remote machine.

Using a Shared File System

All hosts must have identical mappings to a common file system.

On Windows systems, network drives must be mapped so that all machines (including the central host) can refer to the central OpenFusion installation directory with the same drive letter. This ensures that a directory path (for example, O:\OpenFusion\domains) will always point to the same location on the central host regardless of which remote machine it is invoked from.

On Unix, use a soft link to achieve the same effect.

Note that it is not possible to use a common file system to link OpenFusion installations running on a mixture of Unix and Windows hosts. In a mixed operating system environment, central configuration can only be performed via a Web server (see Using a Web Server).

Set up the Central Host

On the central host, set up nodes in the Object Hierarchy with each node representing a remote machine. This is described in The Central Configuration Host.

Implementation Repository

It may be necessary to configure remote installations to share a common implementation repository. This is not necessary if the central host is only used for configuration purposes, but it is required if the clients need to communicate with Services running on other hosts (an example is when load balancing is being used, as described in the Load Balancing Service Guide).

The Servers running on each host must be configured to use the common implementation repository. With JacORB, for example, the ORBInitRef.ImplementationRepository property in the jacorb.properties file on each host must be set to point to the location of the common implementation repository's IMR file.

The common implementation repository can be running on any host.

In order to prevent conflicts when starting the Administration Manager with a common implementation repository, the POA Name property (found on the CORBA tab of the Domains node in the Administration Manager) must be unique for each host. To change this property, the Administration Manager must be started for each host with the -noorb option.

Environment Properties

Each remote host requires an OF_DOMAINS_URL environment property set to the domains directory on the remote host. If the shared file system has been mapped correctly, this property should be identical on every host. For example:



set OF_DOMAINS_URL=file://O:\Openfusion\domains



export OF_DOMAINS_URL=file:///usr/users/central/OpenFusion/domains

Each remote host requires an OF_Admin_URL environment property set to the local domains directory. For example:



set OF_Admin_URL=file://C:\Openfusion\domains



export OF_Admin_URL=file:///usr/users/node1/OpenFusion/domains

Using a Web Server

The central configuration host must be running Web server software. (Any third-party Web server will be suitable.)


The OpenFusion distribution includes the Tomcat Web server, but this should not be used to enable remote configuration.

Set up the Central Host

On the central host, set up nodes in the Object Hierarchy with each node representing a remote machine. This is described in The Central Configuration Host.

Configure Remote Singletons

When you add a Singleton to a remote node in the Object Hierarchy, it will have default data locations that apply to the central host. These locations must be changed to point to valid locations on the remote machine. As many of these properties are hidden from the Administration Manager GUI, the underlying XML files must be edited directly (Note: this is normally not recommended, and care should be taken that no errors are introduced into the XML files).

Appendix XML Configuration Files, gives details of the structure and locations of the files which must be edited.

Every Singleton property value which is a directory path should be changed to point to a location on the remote machine. If the central host and the remote machine have exactly the same installation path and directory structure for their OpenFusion installations, these properties will be correct and do not need to be changed.

If hsqldb is used for persistence, ensure that the DB.WAL.DIR property for each Service is set to point to an existing directory on the remote machine, otherwise the Service will not start.

Set the Central Host Properties

Set the properties of the domains node in the Object Hierarchy as described here. (These properties are described fully in Configure Properties.)

Central Configuration Host

This check box should be checked to indicate that the machine is the central configuration host.

OpenFusion Install URL

The URL that remote machines must use to access the central configuration host. This is a http URL which gives the host's machine name. This URL will be determined by the root document directory of the Web server.

For example, if the central configuration host is an NT Server named central with the Web server document directory set to C:\, and the OpenFusion installation on that machine is C:\PrismTech\OpenFusion, then the correct URL will be:

http://central/PrismTech/OpenFusion

If the Web server document directory is set to C:\PrismTech\OpenFusion, however, the correct URL will be:

http://central


Caution: entering an invalid URL will cause fatal problems! Take backups of the OpenFusion installation and be very careful when changing this property.

Configure from Remote Host

This check box should remain clear on the central host. The setting is only needed on remote machines.

Remote OpenFusion Install URL

This setting is not needed on the central host. The property should be locked, as Configure from Remote Host should not have been selected on the central host.

Set up the Remote Machine

To set up a remote machine to use central configuration, the central host must have been configured and the remote machine must have been set up as a node in the central host's Object Hierarchy.

The following properties must be configured for the domains node in the remote machine's Object Hierarchy. These properties are described fully in Configure Properties.

These properties are stored on the remote machine, not the central configuration host, which is why they must be set on each remote machine.

Central Configuration Host

This check box should remain clear on the remote machine. The setting is only needed on the central host.

OpenFusion Install URL

This setting is not needed on the remote machine. The property should be locked, as Central Configuration Host should not have been selected on the remote machine.

Configure from Remote Host

If this machine is to be configured from a central host, this check box must be checked.

Remote OpenFusion Domains URL

A URL which points to the location on the central host that stores the XML configuration files. This will be the OpenFusion installation directory.

This URL will be determined by the root document directory of the Web server.

For example, if the central configuration host is an NT Server named central with the Web server document directory set to C:\, and the OpenFusion installation on that machine is C:\PrismTech\OpenFusion, then the correct URL will be:

http://central/PrismTech/OpenFusion/domains

If the Web server document directory is set to C:\PrismTech\OpenFusion, however, the correct URL will be:

http://central/domains

Working with Central Configuration

When a remote machine is configured from a central host, all of the XML files which hold properties for Services and Singletons are stored on the central host. The remote machine can read from the configuration files but cannot write to them.

Because the remote machine cannot write to its own configuration files, it can never over-ride the configuration set by the remote configuration host. On the remote machine, most properties will be locked.

The only properties which remain unlocked are Dynamic properties (see Type). Changes to these properties will not be stored permanently when the Administration Manager is shut down.

Many main menu options, tool bar buttons, and right-click menu options are disabled on the remote machine. All actions which apply to changing the Object Hierarchy or modifying locked property values are disabled.



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