Usually, a server exports binding information for one or more of its interface identifiers and its object UUIDs, if any, to an entry in a namespace. The namespace is provided by a directory service such as the DCE Cell Directory Service (CDS). The namespace entry to which a server exports binding information is known as a server entry.
To learn about a server that offers a given RPC interface and object, if any, a client can import binding information from a server entry belonging to that server. A client can delegate the finding of servers from the namespace to a stub. In this case, if a binding is accidentally broken, the RPC runtime automatically tries to establish a new binding with a compatible server.
Advantages of using a directory service to obtain binding information include the following:
· It is convenient for large RPC environments. Initial overhead of understanding and configuring a directory service is balanced by easier management over time.
· Management of data in a directory service is more automated.
· It is effective in dynamic end-user environments.
· Binding information is stored in a named server entry. Data can be dynamic. Servers can automatically place their binding information in the namespace. Changes in binding information are made once by a server or administrator and then propagated automatically by the directory service to the replicas of the data.
· There is centralized administration of data in a namespace. Sophisticated access control is possible.
· It supports searching for and choosing services based on an interface identifier and object UUID. Clients access data by specifying an entry name. Groups and profiles in directory service entries provide search paths for importing binding information.