OSF DCE Application Development Guide--Core Components

RPC Fundamentals
Figure 12-2. Information Used to Identify a Compatible Server
System
Server
Interface
Object
Interface UUID & version numbers
Object UUID
Network
Protocol sequence
Network
address
Endpoint
Comm. protocols
12.3.3 HowClients Obtain Server Binding Information
When a client initiates a series of related remote procedure calls, the RPC runtime tries
to establish a binding, which requires the address of a compatible server. An RPC client
can use compatible binding information obtained from either a namespace or from a
string representation of the binding information. Using the namespace is the most
common approach.
Establishing a binding also involves requesting an endpoint from the endpoint mapper of
the server’s system.
12.3.3.1 Binding Information in a Namespace
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.
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