Service Oriented Architecture

SOA :
A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.

Service:
A service is a function that is well-defined, self-contained, and does not depend on the context or state of other services

Orientation:
When we are building our systems we are looking at them from a service point of view or orientation. This implies that we are oriented or interested in the following:

• Granularity: The level of service interface or number of interactions required with the service, typically characterized as course grained or fine grained.
• Collaboration: Services may be combined together to create higher level or composite services.
• Universality: All components can be approached from a service perspective. For example, a business process may also be considered a service that, despite its complexity, provides inputs and outputs.

Architecture:
It implies a consistent and coherent design approach. This implies a need to understand the inter-relationships between components in the design and ensure consistency in approach. Architecture suggests that we adopt some of the following principles:

Consistency: The same challenges should be addressed in a uniform way.For example, the application of security constraints needs to be enforced inthe same way across the design. Patterns or proven design approaches can assist with maintaining consistency of design

Reliability: The structures created must be fit to purpose and meet the
demands for which they are designed.

Extensibility: A design must provide a framework that can be expanded in ways both foreseen and unforeseen. See the break out box on extensions.

Oracle Adapter for event mediation service( soa suite 11g)

Today Oracle SOA Suite 11g offers new Service Component Architecture (SCA) and Service Data Objects (SDO) which are new standards simplifying service-oriented architecture (SOA) and are also the key enabler of the service platform.
SCA gives developers and architects the ability to represent business logic as reusable components that can be easily integrated into any SCA-compliant application or solution. The resulting application is known as a composite application.
SDO specify a standard way to access data and can be used to modify business data regardless of how it is physically accessed. Developers and architects do not need to know the technical details of how to access a particular back-end data source in order to use SDO in their composite applications. Consequently, they can use static or dynamic programming styles and obtain connected as well as disconnected access.
SOA composite is a standards-based deployment unit that leverages the SCA assembly model and can mix variety of components like ESB routing (Mediator), BPEL, Human Workflow, etc.
Oracle SOA Suite 11g showcases the support for the Service Component Architecture (SCA) standard in Oracle SOA Suite through the new composite assembly editor in JDeveloper as well as a unified service engine foundation for the full set of SOA Suite components.

Related Work:

The most important service from SOA Suite 11g is the Event Delivery Network (EDN) that uses Event Definition Language (EDL), which is fully declarative and can build decoupled applications. One of things I wanted to look into was the Event Delivery Network (EDN) that allows an Event Driven Architecture (EDA) to loosely couple different processes. The events that occur in one process can be published asynchronously and can be consumed at another end on the EDN. The consumed end will typically be Mediator services.
In this article I will implement a File Adapter service to get information for Employee details using a file, the data from this file is transformed and routed by Database Adapter to insert the values directly into the database using Oracle JDeveloper 11g as this new IDE supports EDN. Here the new Employees are considered as new events that we are going to publish.

Prerequisites:
Installed machine on whch Oracle JDeveloper 11g and Oracle SOA Suite 11g and Oracle Database are available.

Process Description:

Lets look at the implementation steps below:......

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