CORBACORBA componentsObject Request BrokerStatic Invocation InterfaceORB to ORBCORBA ServicesCORBACSIS 4490 N-Tier Client/ServerDr. HogansonCORBA•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 communicateCORBACSIS 4490 N-Tier Client/ServerDr. HogansonCORBA components4 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 OMGCORBACSIS 4490 N-Tier Client/ServerDr. HogansonObject Request Broker•Object Request Broker (ORB)•Middleware – applications communicate to ORB•ORB is horizontal integrationClient ApplicationCORBA ORB Middle-wareNOSPhysical NW LayersServer ApplicationCORBA ORB Middle-wareNOSPhysical NW LayersObject RepositoryCORBACSIS 4490 N-Tier Client/ServerDr. HogansonStatic 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 timeCORBACSIS 4490 N-Tier Client/ServerDr. HogansonORB to ORB•Communication between object repositories to locate objects•IIOP – Internet Inter-ORB ProtocolAnother protocol definition•Common data representation (CDR)•Message formats•Message transport requirmentsCORBACSIS 4490 N-Tier Client/ServerDr. HogansonCORBA 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