CORBA - CiteSeerX

CORBA - a middleware for distributed
objects
Sophie Chabridon and Chantal Taconet
INT - Département INF - Systèmes répartis
CORBA
Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Outlines
Middleware for distributed objects : general concepts,
CORBA architecture,
First steps in CORBA: a simple application,
CORBA IDL and mapping to java,
CORBA programming with java : POA, GIOP/IIOP,
IOR ...
Naming and Trading services,
Recent CORBA specifications and perspectives
Bibliography
CORBA - a middleware for distributed objects 1

Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Introduction
Middleware definition
Distribution models
Principles of distributed objects
–Stub and skeleton, Proxy object and inheritance
–Development principles
–Multi-languages (multi-ORBs, multi-OSs)
–ORB definition
–Inherent complexity of distribution
–Main distributed object middleware
CORBA - a middleware for distributed objects 2
Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Middleware
Operating
System
Operating
System
Middleware Middleware
Interface
Application Objects Application Objects
network
CORBA - a middleware for distributed objects 3

Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Middleware
The middleware is a software layer providing :
programming interfaces,
data exchange format,
a protocol for interoperability
to support distribution.
CORBA - a middleware for distributed objects 4
Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Distribution models
Point to point message (Message Oriented
Middleware - MOM)
Point to multipoint message
event/action
client/server
mobile code
virtual shared memory
CORBA - a middleware for distributed objects 5

Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Client-server models
Traditional (Remote Procedure Call - RPC)
Object-oriented (Remote Method Invocation - RMI)
Data-oriented (using SQL requests)
web-based (using HTTP requests)
CORBA - a middleware for distributed objects 6
Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Middleware for distributed objects
Comes from two technologies :
objects (inheritance, encapsulation and
polymorphism)
RPC or Remote Procedure Call (distribution,
heterogeneity, data marshalling and unmarshalling)
CORBA - a middleware for distributed objects 7

Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Goal : interoperability
existing “legacy code”,
numerous languages,
several operating systems,
various hardware,
several network protocols
need for interoperability!
CORBA - a middleware for distributed objects 8
Sophie Chabridon and Chantal Taconet, CORBA Introduction
.
Principle of distributed objects
Automatic generation
stub and skeleton
implementationclient
client skeleton implementation
stub
client implementation
skeleton
stub communication
messages
Interface (contract)
};
j=RI−>submitDoc() j=I.submitDoc()
interface Printer {
Task submitDoc ();
CORBA - a middleware for distributed objects 9