Name space federation

 

Federating name spaces involves binding contexts from one name space into another name space.

For example, assume that a name space, NAME1, contains a context under the name a/b, and that name space, NAME2 contains a context under the name x/y. If context x/y is bound into context a/b and named f2, the two name spaces are federated.

Binding f2 is a federated binding because the context associated with that binding comes from another name space. From NAME1, a lookup of the name a/b/f2 returns the context bound under the name x/y in NAME2.

If context x/y contains an EJB bound under the name ejb1 , the EJB home could be looked up from NAME1 using a/b/f2/ejb1. Notice that the name crosses name spaces. This fact is transparent to the naming client.

In a WAS name space, you can create federated bindings with the following restrictions:

  1. Federation is limited to CosNaming name servers. A WAS name server is a Common Object Request Broker Architecture CosNaming implementation. One can create federated bindings to other CosNaming contexts. One cannot, for example, bind contexts from an LDAP name server implementation.

  2. If you use JNDI to federate the name space, use WAS's initial context factory to obtain the reference to the federated context. If you use some other initial context factory implementation, you either may not be able to create the binding, or the level of transparency may be reduced.

  3. A federated binding to a non-WAS naming context has the following functional limitations:

    1. JNDI operations are restricted to the use of CORBA objects. For example, you can look up EJB homes, but you cannot look up non-CORBA objects such as data sources.

    2. JNDI caching is not supported for non-WAS name spaces. This restriction affects the performance of lookup operations only.

  4. Do not federate two WAS stand-alone server name spaces. Incorrect behavior may result. If you want to federate WAS name spaces, use servers running under the Network Deployment or Enterprise packages of WAS.

Naming
Configure and viewing name space bindings
Using naming