Middleware Ppt 33392m

Presented By:Sudipta Dhara Roll-1070100

Table of Content 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Introduction How it evolved Need of Middleware Middleware Basic Categories of Middleware CORBA Components of CORBA Middleware tools Conclusion References

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Introduction 

Middleware is computer software that connects distributed software components or applications.  The distributed software consist of a set of services that allows multiple processes running on multiple machines to interact across a network.  Middleware sits “in the middle” between application software working on different Operating Systems.

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How it evolved 

Till 1980 most computing was based on central host computers. The term middleware first appeared in the late 1980s to describe network connection management software.  RPC was first developed circa 1982 by Birrell and Nelson. Early RPC systems that achieved wide use include those by Sun.  Then The OMG was formed in 1989, In the late 1990s HTTP became a major building block for various kinds of middleware. 4

Need of Middleware 1. Middleware reduces application development and maintenance efforts. 2. Middleware provides distributed computing. 3. Distributed application without middleware are impractical.

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Middleware Basics Middleware services are sets of distributed software that provide a more functional set of APIs than does the operating system and network services.This increased functionality allows an application to:  Locate transparently across the network, providing interaction with another application or service.  Be independent from network services.  Be reliable and available.  Scale up in capacity without losing functionality. 6

Categories of Middleware There are different kinds of middleware These are-

1.Transaction Processing(TP) Monitor Technology. 2.Message Oriented Middleware(MOM). 3.Remote Procedure Call(RPC). 4.CORBA. 5.Homegrown middleware solutions.

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Common Object Request Broker Architecture (CORBA)  Driven by Microsoft and OMG.  It’s a standard architecture for distributed object systems.  It allows distributed, heterogeneous collection of object to interoperate.  The concepts are defined in such a way that they can be mapped to a number of programming languages.  It does not include language constructs to store variables or to express algorithms. 8

CORBA (Contd…)  IDL is designed to be independent of a particular programming language, though its syntax is oriented towards C++.  CORBA defines bindings to: C, C++, Smalltalk, Ada, Java and Cobol. These programming language binding determines how object type operations are implemented in server object and how client can make object request. 9

Component of CORBA  Client Stubs create and issue requests on the client 

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side. Dynamic invocation is done by Dynamic Invocation Interface, Here control is recursively given back to the client object until it polls for operation result. ORB Interface Interact between Object Request Broker(ORB Core), Client and Server Objects at run time . ORB activate the object using Object Adapter. Implementation Skeletons receive and forward requests to objects on the server side. The skeleton finally calls the operation that was requested by the client. 10

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Middleware Tools

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Conclusion  Middleware was born for reuse by way of abstraction.  Currently middleware research and development has reached a new phase.  But the following questions are still open to resolve.

What kind of abstraction will we need in the next step? Can we build a general model for all the middleware and customize the necessities to fit the applications when needed?

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References  http://www.chetanasprojects.com/ThreIDDLEWARE-TECHNOLOGY-Seminar  http://seminarprojects.com/Thread-middlewaretechnologies  http://eprints.ucl.ac.uk/674/1/corba  http://www.swinggrid.ch/resources/middleware_tools  http://cabibbo.dia.uniroma3.it/ids/altrui/middlewarebakken

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