CORBA naming service

A CORBA server puts references to CORBA objects inside a naming service so that clients can query the naming service and obtain the object reference, then call operations on the CORBA objects. Typically, a client queries the naming service once, then caches the object reference.

A CORBARequest node is a CORBA client; therefore, when it is deployed, the node contacts a naming service to obtain an object reference. If the object reference is not in the naming service at deployment time, or the naming service that is configured on the node is unavailable, the CORBARequest node issues a warning, and attempts to contact the naming service to get the object reference when it receives a message. If an object reference cannot be acquired from the naming service when the node receives a message, an error is issued. You can specify the location of an object reference by using the properties on the CORBARequest node, or by using the CORBA configurable service. For more information, see CORBARequest node and Defining where the CORBARequest node gets the object reference.

Identifying an object reference in a naming service

Each object in a naming service has a unique name. You must use this name when you configure the Object reference name property on the CORBARequest node.

Naming services are typically arranged in a hierarchy so that names can be given context or scope. The initial naming context is at the top of the hierarchy. Object references can be added to the initial naming context, and additional contexts can exist below it. The number of levels in the hierarchy is unlimited.

Object references and contexts can be assigned a kind to facilitate grouping. The kind is appended to the context in the format context.kind. If you are using IBM® Integration Bus to access an external CORBA application, you need to know the location of the naming service and the name of the object reference in the naming service. The following example shows how to determine the exact string representation of the name.

In the diagram, contexts are represented by squares, and object references are represented by circles.

• An object called Factory is directly attached to the initial naming context.
• Three contexts, with kind region, are also attached to the initial naming context.
• These three contexts each have one or more object references attached to them.
• The Europe context has an England context attached to it, of kind country, which has an object attached to it (Calculator).

The name that you specify when you configure the Object reference name property on the CORBARequest node reflects the position of the object in the hierarchy. The following table shows how to refer to the specific objects in the diagram.

Object	Object reference name
Factory	Factory
Bank	Asia.region/Bank.object
Mail	Asia.region/Mail.object
StockExchange	America.region/StrockExchange.object
Market	Europe.region/Market.object
Calculator	Europe.region/England.country/Calculator

All objects in the naming service can be connected directly to the initial naming context; in which case, their names would be in the same format as the Factory object in this example.