L3-Integrative programming and Tech

​The need for integration

• organizations consist of more than one department

• applications interact with each other to achieve the overall objective of the organizations​

• running department specific applications​

​Reasons for integration

• Technology change affects all layers; legacy does not go away so easily.

• The architecture of the organization information system depends on constraints related to the

  technology but also to the organization.

• Within an enterprise, each department may have its own IT infrastructure, systems and databases which are maintained independently. Integrating them may bring additional value to

  the company.

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• Updating and integrating of applications is possible whenever required. New applications can be created by integrating real time data from different parts of the enterprise

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​Reasons for integration

​Integration models

• Presentation integration

• Data integration and

• Function integration

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​Presentation integration model

allows the integration of new software through the existing presentations of the legacy software. This is typically used to create a new user interface but may be used to integrate with other applications.

​Data integration model

allows the integration of software through access to the data that is

created, managed and stored by the software typically for the purposes of reusing or synchronizing data across applications.

​Functional integration model

allows the integration of software for the purpose of invoking

existing functionality from other new or existing applications. The integration is done through interfaces to the software.

​Fundamental Challenges of Integration

LESSON 3

The challenges of integration

• Network unreliability

• Distributed systems

• Slow networks

• Heterogeneity

• Modification complexity

​Network is unreliable

Integration solutions have to transport data from one computer to

another across networks.

​Distributed systems

in the worst case, every application runs on a completely separate environment, e.g., database storage is not shared among applications.

​Networks are slow.

Sending data across a network is multiple orders of magnitude slower than making a local method call.

​Any two applications are different.

Integration solutions need to transmit information between systems that use different programming languages, operating platforms, and data formats.

​Heterogeneous

each application implements its own data model. Concepts may be shared, but representation mismatches are to be expected. Mappings and transformations are required.

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​Change is inevitable

Applications change over time. An integration solution has to keep pace

with changes in the applications it connects.

​Integrative Technologies/methods for integration

LESSON 3

​Application integration

is an integration framework composed of a collection of technologies and services which form a middleware or "middleware framework" to enable integration of systems and

applications across organizations.

​File Transfer

one application writes a file that another later reads. The applications need to agree on the filename and location, the format of the file, the timing of when it will be written and read, and who will delete the file.

​Shared Database

multiple applications share the same database schema, located in a single physical database. Because there is no duplicate data storage, no data has to be transferred from one application to the other.

​Shared Database

multiple applications share the same database schema, located in a single physical database. Because there is no duplicate data storage, no data has to be transferred from one application to the other.

​Remote Procedure Invocation

one application exposes some of its functionality so that it can be accessed remotely by other applications as a remote procedure. The communication occurs real-time and synchronously.

​Messaging

one application publishes a message to a common message channel. Other applications can read the message from the channel at a later time.