CORBA Concepts (GIOP, IIOP, IOR, ORB, IDL)

CORBA Concepts (GIOP, IIOP, IOR, ORB, IDL)

Corba
The common Object request broker (Scheduler) program architecture (Common object Request broker Architecture), abbreviated to CORBA, is an object management organization (objects Management Group) in response to the demands of today's fast-growing hardware and software collaboration capabilities. In short, CORBA allows applications to communicate with other applications, regardless of where or by whom they are designed.
CORBA was once the mainstream technology of distributed computing, and it is widely used in telecom and other fields. The high cost of development and deployment is now a largely abandoned technology, replaced by lightweight Web services, restful services, and so on.

Ior
An interoperable object reference.

ORB (Object Request Broker)
Object Request Agent. The ORB is a middleware that establishes a client-server relationship between objects. With the ORB, a customer can easily use the server object's method regardless of whether the server is accessed on the same machine or through a network. The ORB intercepts the call and then is responsible for finding an object that implements this request, passing parameters and methods, and finally returning the result. The client does not have to know where the object is, what language is implemented, his operating system, and other things unrelated to the object interface.

ORB Daemon
is responsible for locating the object implementation specified by the IOR and establishing a connection between the client and the server. Once the connection is established, GIOP defines a set of messages that are used by the client for the request or for the server to respond to.

GIOP (General Inter-ORB Protocol)
The GIOP (Common Object request inter-Agent communication Protocol) component provides a standard transport syntax (low-level data representation) and an information format set for communication between the Orb. The GIOP can only be used between the Orb and the Orb, and can only be used in a connection-oriented transport protocol that meets the desired conditions. It does not need to use a higher layer of RPC mechanism. This protocol is simple (as simple as possible, but not simplistic), upgradeable and easy to use. It is designed to be mobile, performance-efficient, and less dependent on other low-level transport protocols. Of course, because different transports use different versions of GIOP, they may not work directly together, but it can easily connect to the network domain.

IIOP (Internet inter-orb Protocol)
The IIOP (Internet Object Broker Communication protocol) component indicates how to exchange GIOP information over a TCP/IP connection. IIOP provides the internet with a standard collaborative work protocol that enables compatible orbs to collaborate on the "out of the box" approach based on today's popular protocols and products. It can also be used for protocols between two half bridges (half-bridges). This protocol can be used for collaboration between any Orb and IP (Internet Protocol) domain, unless the Orb chooses a special protocol. At this time, it is the basic Inter-ORB protocol in the TCP/IP environment, the most common transport layer.
GIOP is not based on any special network protocol, the OMG in the most widely used communication transmission platform--TCP/IP on the standardized GIOP,GIOP plus TCP/IP equals IIOP

Idl
The IDL full name Interface Definition language is a canonical language used to describe the interface of a software component. Users can define modules, interfaces, properties, methods, input and output parameters, and even exceptions. IDL is implemented in different languages, and the interface described in IDL can be compiled into the target language, including the client Agent and server-side framework, the corresponding helper classes, and so on. For example, Java has provided the IDLJ command to compile.

The relationship between CORBA and Orb
CORBA's distributed object invocation capability relies on the Orb, and the communication between the orbs is accomplished through the GIOP protocol. GIOP defines the transfer syntax and standard message format for inter-operation between the Orb, such as the request header, the fields contained in the request body, and the length.

The relationship between IIOP and GIOP
The relationship between IIOP and Giop is like the relationship between special language and OMG IDL, GIOP can be mapped to different layers, it can specify protocol. Just as IDL cannot see a complete program, GIOP itself does not provide a complete collaborative effort. Iiop and other similar mappings on different transport layers to achieve an abstract GIOP definition.
GIOP is an abstract protocol, and IIOP is a concrete implementation that defines how GIOP messages are exchanged through the TCP/IP protocol. So we usually say that CORBA is based on the IIOP protocol.

Above article go to http://www.cnblogs.com/nliao/p/3308669.html