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See:
Description
Interface Summary | |
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DaNameServerI | |
DaNameServerIOperations |
Class Summary | |
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_DaNameServerIStub | |
DaNameServerI_impl | Defines the Aida Directory Service API implementation. |
DaNameServerIHelper | |
DaNameServerIHolder | |
DaNameServerIPOA | |
NameServer | NameServer is the AIDA directory service server. |
Defines Aida's Directory Service server.
This package defines the Aida peer DaNameServerI
.
The "main" program of
daNameServer is NameServer
, which hosts a DaNameServerI
.
This is the
special Aida peer which
acts as Aida's Directory Service. The Aida API objects, DaObject
and Dareference
, call methods of DaNameServerI_impl
to
discover the Data Providers necessary to satisfy the Aida query they are
processing. The Directory Service information is
stored in an external SQL database, which DaNameServerI_impl
accesses to retrieve information about each entity/attribute "known" by Aida.
In addition to its function as a Directory Service for data,
daNameServerI
acts as a Name Server for all Aida peers. That is,
each peer in the Aida network; each Data Provider, and DaServer
,
tells DaNameServerI
its CORBA IOR (Interoperable Object Reference)
when it initializes. Each Aida peer, and each client program, discovers the IOR
of any
peer by asking DaNameServer
. With the IOR of a peer, the program (peer or
client) can
contact it directly. The most important example of this is when a client
application program constructs a new Aida API object DaObject
. At
that time, DaObject
contacts the NameServer
(NameServer
deploys a DaNameServerI
) to find out the
IOR of the DaServer - the Aida peer which processes queries for client programs.
From that point on, DaObject
uses DaNameServerI
in
its capacity as a Directory Service to translate requests for entity/attribute
pairs into specific queries against Aida Data Providers (see above).
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