Survey of Distributed Objects Middleware JINI, CORBA and HLA.

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Survey of Distributed Objects Middleware
JINI, CORBA and HLA.

• Simon El-Khoury
• University of Montreal, Department of Computer
  science
• Course IFT6275
• Telematic
• Professor Kropf Peter

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Overview

• Middleware
• JINI
• CORBA
• HLA
• Comparison and Criticisms
• Conclusion

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Middleware
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Jini Context
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Key Concepts

• Services
• Lookup Services
• Leasing
• Transaction
• Events

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Services

• Services may be added or withdrawn from a Jini
  federation at any time.
• Jini provides mechanisms for service
  registration, lookup, and use.
• Services communicate by using a service
  protocolset of Java interfaces.

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Lookup Services

• Repository of available services
• Service objects may be downloaded to a client as
  required
• May be federate with other lookup services
• Lookup service interface provides
• Registration, Access, Search, Removal

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Discovery and Lookup Protocols

• Allow a Jini service (hardware or software) to
• Find and join a group of Jini services
• Advertise capabilities/services
• Provide required software and attributes

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Discovery Protocol
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Join Protocol
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Lookup Protocol
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Client Uses Service
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Overview of CORBA
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What is CORBA ?

• CORBA provides a software infrastructure of
  communication for the distributed applications.
• Standard CORBA offers a total solution to treat
  the heterogeneity of the distributed
  applications.
• The services objects and the common utilities of
  CORBA provide a vast range of software components
  to build distributed applications .

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CORBA ORB Architecture
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The IDL Language
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Interface Example
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High Level Architecture (HLA)
Functional View of the HLA
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Definition of HLA

• HLA Interface Specification
• HLA Object Model Template (OMT)
• HLA Rules

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Run Time Infrastructure (RTI)

• Federation management
• Declaration management
• Object management
• Ownership management
• Time management
• Data distribution management

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Comparison and Criticisms

• CORBA
• Free Programming langage choice
• no fully standardisation
• Complicated programming model

• Jini
• Java environment
• Standard
• dynamic services
• A simple programming model

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Comparison and Criticisms

• Common Properties
• Provide Objects Repository
• Subscription/Publication Model
• Choosing, monitoring and maintaining the
  interaction sessions

• HLA
• Simulation real Time
• HLA need to pass a whole data in a near time
• Integrate HLA with CORBA

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Conclusion

• Interoperability
• Spontaneous Network
• Transparent Communication
• Share and Manage Resources

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References

• Jini
• http//www.jini.org
• http//www.sun.com/jini
• Core Jini, by Keith Edwards, Prentice-Hall, 1999.

• CORBA
• http//www.corba.com
• Inside CORBA, William A. Ruh and Thomas J.
  Mowbray, Addison-Wesley, 1997.

• HLA
• DMSO High Level Architecture
  Homepage.URL http//hla.dmso.mil

• MiddleWare
• http//www.globecom.net/draft

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THE END

• Presented
• by
• Simon El-Khoury