1. Common Object Request Broker Architecture (CORBA)

2. What is CORBA
CORBA (Common Object Request Broker Architecture) is a standard that enables an object written in one programming language, running on one platform to interact with objects across the network that are written in other programming languages and running on other platforms. For example, a client object written in C++ and running under Windows can communicate with an object on a remote machine written in Java running under UNIX.

3. CORBA’s history
The CORBA specification was developed by the Object Management Group (OMG).
The OMG is an international, not-for-profit group consisting of approximately 800 companies and organizations defining standards for distributed object computing
CORBA is only one of the specifications they develop. They are also behind other key object oriented standards such as UML (Unified Modeling Language).
The OMG was established in 1988 and the initial CORBA specification came out in Over the past 10 years significant revisions have taken place.
Version 2.0, which defined a common protocol for specifying how implementations from different vendors can communicate, was released in the mid-nineties.
The current version of CORBA is 3.0, which introduced the CORBA Component Model.

4. Corba today
Today, CORBA serves as middleware for a variety of large enterprise level applications.
One of the most important and most frequent uses is for servers that must handle a large number of clients, at high hit rates, with high reliability.
The current users of CORBA are diverse - including The Weather Channel, GNOME, US Army, CNN, and Charles Schwab.

5. Standard call and return

6. Corba architecture

7. 3 tier corba architecture

8. Primary elements IDL Client / Server CORBA Objects ORBs GIOP / IIOP
Interface Definition Language
Client / Server CORBA Objects
Abstract objects based upon a concrete implementation
ORBs
Object Request Brokers
GIOP / IIOP
General and Internet Inter-Object Protocols

9. Interface definition language
Defines public interface for any CORBA server.
C++ like syntax
Client and Server implemented based on compilation of the same IDL (usually)
OMG has defined mappings for:
C, C++, Java, COBOL, Smalltalk, ADA, Lisp, Python, and IDLscript
Pass by reference and by value
In, out, and inout parameters
Inheritance
Throwing of exceptions
The Any Type
Callbacks
Enables Peer-to-Peer Object Communication.
Also supports:
structs, unions, enumerations, all c++ scalars, arrays, sequences, octets, strings, constants, and typedefs.

10. Steps to write corba object in java

11. Client server corba object

12. Implemented via a Servant
Abstract
Do not have their own implementation. The elements of a CORBA object (interface, implementation, and location) are held rendered via other elements.
Implemented via a Servant
A servant is a block of code (usually an instance of a class) which implements the public interface of the CORBA object. Depending on the server policies, there may or may not be multiple instances of the servant and it may or may not be multi-threaded.
Configured in code or at server startup
Unlike COM+ and EJB the policies for a CORBA object which control things such as Security, threading, and persistence are not console configurable

13. Object request brokers (ORB)
Responsible for all communication
Locating objects
Implementation specific
Known IOR(Inter-Object Reference)
Naming and Trading Services( DSN-like)
Transferring invocations and return values
Notifying other ORBs of hosted Objects
Must be able to communicate IDL invocations via IIOP
If an ORB is OMG compliant, then it is interoperable with all other OMG compliant ORBs
Interface Repository
A Database of all of the IDL for compiled objects running on the ORB
Implementation Repository
A Database containing policy information and the implementation details for the CORBA objects running on the ORB
Load Balancing
Fail-over support
Security

14. Object Management Architecture(OMA)
Center of all the activity undertaken by OMG
OMA specifies a range of architectural entities surrounding the core ORB, which is CORBA proper
Detailed specifications for each component and interface category is populated in OMA reference Model

15. 3 benefits of oma
Coding is quicker, so application can be deployed sooner
Applications designed around discrete services have better architecture
Many OMA implementations have enterprise characteristics built in: they’re robust, and they scale

16. Corba services
CORBA Services provides basic functionality, similar to the services that system library calls do in UNIX. Functions includes creating objects, controlling access to objects, keeping track of relocated objects and to consistently maintain relationship between objects.
Horizontal CORBA Facilities sit between the CORBA services and Application objects. These components providing support across an enterprise and across business. Four facilities: the Printing Facilities, the Secure Time Facilities, the Internationalization Facilities, and Mobile Agent Facilities.
Domain(Vertical) CORBA Facilities are the most exciting work at OMG. Define a standard interfaces for standard objects shared by companies within a specific vertical market(e.g. healthcare, manufacturing, finance). Now nine industries have their own OMG task force.