SOA
SOA stands for service oriented architecture. From OOA to SOA, computing and development approach of software services are changing rapidly.
SOA are based on a mesh of software services. Services comprise unassociated, loosely coupled units of functionality that have no calls to each other embedded in them. Each service implements one action, such as filling out an online application for an account, viewing an online bank-statement, or placing an online booking or airline ticket order. Instead of services embedding calls to each other in their source code they use defined protocols that describe how services pass and parse messages, using description meta-data.
The developer associates individual SOA objects by using orchestration. In the process of orchestration the developer associates software functionality (the services) in a non-hierarchical arrangement (in contrast to a class hierarchy) using a software tool that contains a complete list of all available services, their characteristics, and the means to build an application utilizing these sources.
Underlying and enabling all of this requires meta data in sufficient detail to describe not only the characteristics of these services, but also the data that drives them. Programmers have made extensive use of XML in SOA to structure data that they wrap in a nearly exhaustive description-container. Analogously, WSDL typically describe the services themselves, while SOAP describes the communications protocols. Whether these description languages are the best possible for the job, and whether they will remain the favorites in the future, remains an open question. In the meantime SOA depends on data and services that are described metadata that should meet the following two criteria:
- the metadata should come in a form that software systems can use to configure dynamically by discovery and incorporation of defined services, and also to maintain coherence and integrity
- the metadata should come in a form that system designers can understand and manage with a reasonable expenditure of cost and effort
SOA requirements - What are the requirements that we need for a system to be SOA compliant.
SOA tutorial - Basic tutorial on SOA.(Reference - http://www.wikipedia.org)
Introduction - When should SOA be used
