midddleware technologies

Middleware
It is the Infrastructure that supports (distributed) component- based application development. It provides mechanisms to enable component communication, mechanisms to hide distribution information and a set of predefined components. They are the Standard for constructing and interconnecting components interchange
,upgrade, adaptation, aggregation etc.

Middleware Requirements
Network communication for marshalling/unmarshalling, Reliability for delivery guarantees, total/partial ordering, atomicity and replication, Coordination for activation/termination, threading, group requests, synchronicity etc, Heterogeneity for supporting different platform, operating system, network OS, programming language etc.

The Elements of Middleware
1)Software components including component interfaces, properties, events, methods etc.
2)Metadata: It is the self-descriptive information used by a component to flexibly
communicate with others
3)Containers: They provide access to system-level services and shared context of interaction with other components.
4)An Integrated development environment like the VisualCafe for Java for example.

Distribution Support in Middleware:
The following Five distributed services are required:
1)remote communication protocols
2)security services
3)directory services
4)system management services
5)transaction services


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MIDDLEWARE TECHNOLOGIES
-A MEDIUM OF COMMUNICATION

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Presented BY
D.GEETHA AMRUTHA
SRI INDU COLLEGE OF ENGG AND TECH
A.SWETHA
SRI INDU COLLEGE OF ENGG AND TECH
TO:
TKR COLLEGE OF ENGINEERING AND TECHNOLOGY

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CONTENTS

ABSTRACT
WHAT IS MIDDLEWARE
INTRODUCTION
MOTIVATION OF MIDDLEWARE
REQUIREMENTS OF MIDDLEWARE
APPLICATIONS OF MIDDLEWARE
LIMITATIONS
USAGE CONSIDERATIONS
CONCLUSION

ABSTRACT
The future of technology at times becomes easier to predict that computer will compute faster, materials become stronger.
To think is easy, to act is difficult but to act according to the thinking is typical task, which has now become possible through present technology of which one of the outcome is middleware “ a best way to communicate faster.
Middleware is essential to migrating mainframe applications to client/server applications and to providing for communication across heterogeneous platforms.
This paper defines "middleware," reviews a few examples of some major middleware technologies such as computer networks, telecommunications, uninterruptible power supply, decentralized manufacturing units and describes factors for comparing technologies. Middleware enables integration of components with each other, such as adding GIS capabilities to other enterprise information systems such as Outage Management, Customer Information, and Enterprise Resource Planning. Middleware provides the glue that transparently connects these systems, reducing development costs and enabling components to change without affecting other components. Examples of middleware technologies include DCOM, CORBA, JAVA, RPC/DCE, MQS, and XML. Each of these technologies has different capabilities and considerations for use. Such factors can be used to evaluate most other middleware technologies.
Middleware is a technology, that can change the way of living of human beings such that¦.
Which can produce super super computers¦
Soft electronic goods with extra-ordinary properties ¦
Rapid communications and change the face of science.

WHAT IS MIDDLEWARE

Middleware is software that is invisible to the user.
In a distributed computing system middleware is defined as the software layer that lies between the operating system and the applications on each site of the system.
Middleware is essential to migrating mainframe applications to client/server applications and to providing for communication across heterogeneous platforms.
INTRODUCTION:
This technology has evolved during the 1990s to provide for interoperability in support of the move to client/server architectures (see Client/Server Software Architectures
Middleware is a layer of software that can support
¢ Multiple communication protocols
¢ Multiple programming languages
¢ Multiple computer platforms
It acts as the glue that holds components together, as an insulator that protects business logic developers from complex network protocols, and as a facilitator for reducing conflicts between platforms.
Infrastructure that supports (distributed) component based application development
a.k.a. distributed component platforms
mechanisms to enable component communication
mechanisms to hide distribution information
(large) set of predefined components
Standard for constructing and interconnecting components
Interchange
Adaption
Aggregation
Upgrade.
->INTERCHANGE OF INFO
) The most widely-publicized middleware initiatives are the Open Software Foundation's Distributed Computing Environment (DCE) , Object Management Group's Common Object Request Broker Architecture (CORBA), and Microsoft's COM/DCOM (see Component Object Model (COM), DCOM, and Related Capabilities) [Eckerson 95].

MOTIVATION OF MIDDLEWARE

Geographic Information Systems have evolved from "islands of automation" to systems that need to be integrated with a wide variety of other enterprise information systems. These include work management, outage management, customer information, mobile dispatch, and enterprise resource planning systems. A significant portion of the system development part of most GIS implementations now involves establishing interfaces with these other systems. A functional architecture diagram (Figure 1) illustrates this situation.
Middleware has often been selected as an integration tool for adding functionality to legacy systems. For example, a company may decide that their mainframe customer information system needs to be connected with a GIS for supporting new customer service capabilities. Middleware helps this process. Middleware is also the method of choice for developing very large systems from scratch. It allows asynchronous evolutionary development of the different components; the system can begin useful operation without waiting for a single component to implement a non-essential feature.

REQUIREMENTS OF MIDDLEWARE:
Middleware Requirements:
Network communication
Marshalling/unmarshalling
Coordination
Activation/termination, threading, group requests, synchronicity
Reliability
Delivery guarantees, total/partial ordering, atomicity, replication
Scalability
Transparency of access/location/migration/replication, loadbalancing
Heterogeneity
Platform, operating system, network OS, programming

APPLICATIONS OF MIDDLEWARE:
The major applications of middleware are in the areas of:
1.Telecommunication networks
The little revolution
2.Computer networks
3.Decentralized manufacturing units
4.Uniterruptible power supply

Another major applications of middleware is:
A significant number of middleware services and vendors exist. Middleware applications will continue to grow with the installation of more heterogeneous networks. An example of middleware in use is the Delta Airlines Cargo Handling System, which uses middleware technology to page link over 40,000 terminals in 32 countries with UNIX services and IBM mainframes. By 2015, middleware sales are expected to exceed $12 billion.
5.The main purpose of middleware services is to help solve many application connectivity and interoperability problems
Middleware can be useful in one of the following different forms:
o Transaction processing (TP) monitor,which provide tools and an environment for developing and deploying distributed applications.
o Remote Procedure Call (RPCs), which enable the logic of an application to be distributed across the network. Program logic on remote systems can be executed as simply as calling a local routine.
o Message-Oriented Middleware (MOM), which provides program-to-program data exchange, enabling the creation of distributed applications. MOM is analogous to email in the sense it is asynchronous and requires the recipients of messages to interpret their meaning and to take appropriate action.
o Object Request Brokers (ORBs), which enable the objects that comprise an application to be distributed and shared across heterogeneous networks.

MIDDLEWARE APPLICATIONS IN CORBA:
A middleware platform that supports a standardized OOarchitecture for software applications
Common Object Request Broker Architecture
Open standard - developed by the Object Management group
CORBA is a component of OMGâ„¢s Object Management Architecture
CORBA supports distributed object computing
CORBA uses a broker
An intermediary handling requests in a system
Facilitates communication between clients and server objects
Separates a componentâ„¢s interface from its implementation
LIMITATIONS:
Although middleware has numerous obvious benefits in solving application connectivity and interoperability problems, middleware services are not without tribulations. The main issues are outlined below:
¢ There is a gap between principles and practice. Many popular middleware services use proprietary implementations (making applications dependent on a single vendor's product). The commercial off-the-shelf (COTS) software vendors (i.e. TIBCO and Vitria) are addressing this problem through the more stringent use of standardization. In spite of this progress, the issue remains a substantial problem.
¢ The sheer number of middleware services is a barrier to using them. To keep their computing environment manageably simple, developers have to select a small number of services that meet their needs for functionality and platform coverage. Since the goal of middleware is to provide for maximum interoperability, this barrier is particularly frustrating.
¢ While middleware services raise the level of abstraction of programming distributed applications, they still leave the application developer with hard design choices. For example, the developer must still decide what functionality to put on the client and server sides of a distributed application.

USAGE CONSIDERATION:
The following are the three solutions to the above tribulations:
Distributed system services, which include critical communications, program-to-program, and data management services. This type of service includes RPCs, MOMs and ORBs.
Application enabling services, which give applications access to distributed services and the underlying network. This type of services includes transaction monitors (see Transaction Processing Monitor Technology) and database services such as Structured Query Language (SQL).
Middleware management services, which enable applications and system functions to be continuously monitored to ensure optimum performance of the distributed environment.
.
CONCLUSION:
Middleware technology, with all its challenges and opportunities, is an unavoidable part of our future. The possibilities with middleware technology are immense and numerous
Middleware product implementations are unique to the vendor. This results in a dependence on the vendor for maintenance support and future enhancements. Reliance on vendors, in this manner, could have a negative effect on a system's flexibility and maintainability. However, when evaluated against the cost of developing a unique middleware solution, the system developer and maintainer may view the potential negative effect as acceptable. Also, as Java and Internet protocol middleware technologies evolve, many of these potentially detrimental issues will dissolve.
The challenges of designing, building, and maintaining large-scale, distributed enterprise systems are truly daunting.
Middleware will help ust to rise above the obscuring conflicts of new business objectives, new technologies, and vendor wars so that we can think clearly and productively about the challenges we face.
¢ The Middleware Technology is mature
“ The products used featured good compliance with the OMG standard
¢ Key enabler for the Open Services Market
“ Middleware facilitates open service access
¢ Key enabler for connecting everything together
“ The distributed components of the demonstrator were integrated easily
¢ Improved maintainability and adaptability
“ New servers can be added to balance the loadwithout disrupting service
Middleware can be viewed:
As critical set of infrastructure technologies to lower the cost, time and risk of building state of the- art applications.
As akey source of technological innovation that enables managers to introduce this innovation at their own pace into companyâ„¢s multivendor, distributed computing environments.
As a reliable option for significantly levaraging and extending the protective life of prior IT assests---helping to protect and prolong the value of investments.
This technology helps us to create an Alige e-bussiness and successfully inplement the enterprise applications
BIBLIOGRAPHY:
Journals: THE COMPLETE BOOK OF MIDDLEWARE
Web Sites: google.com
amazon.com