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''' | '''SOA provides another view of providing functionality based upon services offered in terms of protocols and a specific API. To provide services, platforms rely upon principles and the power that can be expressed through reflection and meta programming. Research and report how these critical concepts relate to and support SOA.''' | ||
== Service Oriented Architectures== | == Service Oriented Architectures== | ||
Revision as of 20:42, 8 October 2009
SOA provides another view of providing functionality based upon services offered in terms of protocols and a specific API. To provide services, platforms rely upon principles and the power that can be expressed through reflection and meta programming. Research and report how these critical concepts relate to and support SOA.
Service Oriented Architectures
Service Oriented Architecture is a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains. It provides a uniform means to offer, discover, interact with and use capabilities to produce desired effects consistent with measurable preconditions and expectations.
This makes it easier for software integration of different modules developed by different people. Rather than defining an API, SOA defines the interface in terms of protocols and functionality such that modules following these protocols can easily be integrated together. The main characteristics of SOA are:
- Based on open standards - The governing principles are free for all to use and not protected by intellectual property.
- Interoperable - Diverse systems should be able to work together (inter-operate)
- Autonomous - Services have control over the logic they encapsulate.
- Reusable - Logic is divided into services with the intention of promoting reuse.
- Reliable - It should not have many flaws
- Discoverable - Services are designed to be outwardly descriptive so that they can be found and assessed via available discovery mechanisms
- Loosely-Coupled - Loose coupling occurs when the dependent class contains a pointer only to an interface, which can then be implemented by one or many concrete classes.
- Stateless - Should exhibit the same behaviour and yield the same result whether called once, or 100 times
- Composable - Collections of services can be coordinated and assembled to form composite services.
- Manageable - It should be easy to maintain it
- Secure - It should not be easily hackable
Core Components of SOA
- SOAP: Simple Object Access Protocol -
- WSDL: Web Services Description Language
- UDDI: Universal Discovery, Definition and Integration
- BPEL: Business Process Execution Language
- ESB: Enterprise Service Bus
- WS-*: Web Services Standards