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CORBA. Common Object Request Broker Architecture Published by Object Management Group (OMG) Object-Oriented Middleware Provides object abstraction Is a set of OO middleware specifications that define the way objects are defined, created, dispatched, invoked, and communicate. CORBA components.
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CORBA • Common Object Request Broker Architecture • Published by Object Management Group (OMG) • Object-Oriented Middleware • Provides object abstraction • Is a set of OO middleware specifications that define the way objects are defined, created, dispatched, invoked, and communicate
CORBA components 4 service components/levels • Object services • Domain independent naming, etc. for distributed objects • Common facilities • Domain independent for end-user applications • Domain interfaces • Tailored for specific industries • Application interfaces • Specific to a given application – not standardized by OMG
Object Request Broker • Object Request Broker (ORB) • Middleware – applications communicate to ORB • ORB is horizontal integration Object Repository Server Application Client Application CORBA ORB Middle-ware CORBA ORB Middle-ware NOS NOS Physical NW Layers Physical NW Layers
Static Invocation Interface • SII • Objects interface does not change • Client gets a stub interface • Server gets a skeleton interface • Actual code is located in the object repository • Note that code could change, but object interface is fixed • Works like RPC • Code is fetched from repository at run time
ORB to ORB • Communication between object repositories to locate objects • IIOP – Internet Inter-ORB Protocol Another protocol definition • Common data representation (CDR) • Message formats • Message transport requirments
CORBA Services • Naming – binds names to objects • Events event channels for synchronous communication • Transactions – transactions between objects • Concurrency control – control shared object access • Relationships – capability to represent relationships • Externalization – protocols for externalizing and internalizing objects • Life Cycle – conventions for creating, deleting, copying and moving objects • Persistence – a means to store the state of objects • Routing requests to servers (Object trader) • Sercurity