OSF DCE Application Development Guide--Introduction and Style Guide

OSF DCE Application Development Guide—Introduction and Style Guide
There is an exception to this scheme. Some servers are designed to occupy well-known
addresses. The DCE host daemon itself, dced, is reached in this way, making its
accessibility independent of whether or not the namespace is accessible. The endpoint(s)
of a well-known address do not change; they are usually specified in the application’s
interface specification (contained in its .idl file). Bindings to servers that use well-known
endpoints are already complete at the time of import; the endpoint mapper never sees
these bindings.
5.7 Interface Ambiguity and Partial Bindings
The interface UUID, which was generated by the IDL compiler, uniquely identifies the
set of operations that the client will access through that interface. In short, it identifies
the interface. An interface UUID may also happen to identify a server which offers that
interface. But if more than one server on the same host offers the same interface (which
could easily be the case), the interface UUID alone will not be sufficient to identify a
specific server. The result is that if a remote call comes in with such an ambiguous
interface and a partial binding, the endpoint mapper will have to randomly choose any
one of its eligible registered endpoints, complete the binding with it, and send the call on
to that server.
Imagine several print servers residing on the same machine (see Figure 5-5). Each server
manages a group of printers that share a common physical location. All the printers in
room A are managed by the A print server, all the printers in room B by the B print
server, and so on. Now suppose each of these servers has a separate entry in the
namespace. The following figure shows the sequence of events that occurs.
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