Sunday 20 May 2007

Service Oriented Approach!


Dear all,

Let me give you a quick intro to the latest hot topic in the IT industry,hmm! yes, its the service oriented way of approach...,


SOA is a way of approaching the task of creating software. It can be thought of as either a collection of architectural concepts or a programming model. Within an SOA, all functionality is provided by services as described above. This provides a level of flexibility in deploying and reusing services not previously attained.

However, a SOA is more than just a collection of services; it adds a number of principles. Interoperability is the most important of these and is core to the idea of a SOA. Interoperability is achieved through the use of standards. The Web services standards stand out above all others in satisfying this requirement. Remote invocation is provided through SOAP, service interfaces are described using WSDL, and services are discovered through the use of UDDI. In fact, wherever possible, all aspects of the services should conform to the relevant standards. Showned are the sketch of SOA's approach & its benefits.
Another core feature of a SOA is the reuse of existing assets. Deployment of a SOA within an organization is an exercise in creating services from the existing IT systems and infrastructure. For example, systems exposed using object-based middleware are instead exposed using services that accept documents. Legacy systems such as mainframes can be exposed over standard transports and protocols.

Services should be self-contained, enabling them to be invoked directly by clients where necessary. SOA extends this idea to the aspects of services that might not be considered business logic. These include features such as security, logging, and auditing. Each service within the architecture should provide these features directly. This approach is vital if the deployed services are to form a truly distributed system. For example, a single point through which messages must flow in order to be audited leads to a hub-and-spoke architecture instead of the desired distributed system.
The use of a standardized protocol envelope is an important part of any SOA. The document payload for each service may differ, but a standardized protocol envelope provides a mechanism to support the processing of messages by intermediaries. Such mechanisms are used to support features such as addressing, routing, security, and policies. SOAP defines the envelope and numerous other standards define how headers within the envelope are used.
Once the SOA is in place, the existing IT systems within an organization can be viewed as services that provide business functions. These are easily integrated, because they provide well-defined interfaces and can be accessed using standard protocols and transports. This provides the basis on which to orchestrate services into new services that reflect business processes.

Presentation for the SOA could be found here,

Hope you enjoyed the concept of SOA!

Meet you all with another roborant topic! :)

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