Package edu.stanford.slac.aida.sys.daNameServer

Defines Aida's Directory Service server.


Interface Summary

Class Summary
DaNameServerI_impl Defines the Aida Directory Service API implementation.
NameServer NameServer is the AIDA directory service server.

Package edu.stanford.slac.aida.sys.daNameServer Description

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).

Last modified: Fri May 7