On SOA (Supplemental) _ Other integrated

This business flexibility enables enterprises to speed up development, reduce TCO, and improve access to timely and accurate information. SOA helps to achieve more asset reuse, easier management and faster development and deployment, in today's business environment, change is no doubt, so the rapid response to customer demand, market opportunities and external threats of agility, easy to deal with business services change, development needs more than ever more important.
Various businesses recognize the value of components, modularity, interoperability, and scalable infrastructure:

Component: Leveraging standardized application and resource service Interfaces

Interoperation: Implementing easy information exchange between applications and/or resources

Modular: Mix and match, add deletes, business processes, and infrastructure

Scalable: Start with existing resources, add additional resources on demand

The goal of SOA is to make it more resilient in order to respond more quickly to the needs of business units and enable enterprises to apply the shackles of technology-oriented solutions. SOA can be used as a metaphor for bats, bats to use their own ultrasound to capture food, but also need ultrasound to avoid obstacles, the same enterprise, both want to use software to profit, but also hope that the software to circumvent the risk of the enterprise.

SOA requires developers to design applications from the perspective of service integration, require developers to think beyond application software, build technology on a service basis, consider reusing existing services, or examine how services can be reused to make the business needed to be a driver of functional component selection. It encourages the use of alternative technologies and methods, such as messaging mechanisms, to frame applications by linking them together rather than writing new code. SOA wants to achieve enterprise resource sharing, first of all to transform applications and resources into services (service) and then turn these services into standard services to form the sharing of resources.

SOA services have platform-independent self-describing XML documents designed to improve modularity and reuse between business processes and IT applications, and Web Service description languages (WSDL, Web Services Description Language) are standard languages for describing services.

SOA services communicate with messages, which are often defined using XML schemas (also known as XSD, XML Schema definition). Communication between consumers and providers or consumers and services is much more common in environments where providers are not known. Communication between services can also be viewed as a key business document for internal processing within an enterprise.

Within an enterprise, SOA services are maintained through a registry that acts as a directory listing role. The application looks for and invokes a service in the registry. Uniform description, definition and integration are the criteria for service registration. Each SOA service has a service quality associated with it (QoS, quality for service). Some of the key elements of QoS are security requirements (such as authentication and authorization), reliable communication, and the policy of who can invoke the service.

Different kinds of operating systems, application software, system software and application infrastructure (application infrastructure) are intertwined, which is the status quo of it enterprises. Some existing applications are being used to handle the current business process (business processes), so it is impossible to build a new infrastructure from scratch. Companies should be able to respond quickly to changes in the business, leveraging existing applications and application infrastructure (application infrastructure) to address new business needs, providing new channels of interaction for customers, business partners, and suppliers, and presents a framework that can support the organic business (organic business). SOA, by virtue of its loosely coupled nature, enables enterprises to add new services or update existing services in a modular manner to address new business needs, provide choices to provide services through different channels, and can serve as services to existing or established applications of the enterprise, thereby protecting existing IT infrastructure investments.

To run, manage SOA applications, the enterprise needs an SOA base, which is part of the SOA platform. The SOA base must support all relevant standards and the run-time containers that are required.
Wsdl,uddi and SOAP are the basic components of the SOA Foundation. WSDL is used to describe services; UDDI is used to register and find services, and soap, as a transport layer, is used to send messages between consumers and service providers. SOAP is the default mechanism for Web services, and other technologies enable other types of bindings to be serviced. A consumer can find a service in the UDDI Registry (registry), obtain a WSDL description of the service, and then invoke the service through SOAP.

The concept of SOA is not something new, it represents an evolution, not a revolution, SOA is an agile way of combining existing applications to generate new services, providing the enterprise with greater flexibility to build applications and business processes. I think the existing Web services, workflows, middleware, and now-hot SaaS are all implementations of SOA at different levels. But they are also different, Web services are technical specifications, services that take advantage of a set of standards, and SOA is a design principle architecture pattern, the benefit of using Web services to implement SOA is that you can implement a neutral platform to get services, and as more and more software vendors support more and more Web service specifications, You will achieve better versatility. SOA and SaaS I have a close mind, and SOA is a software architecture and design perspective on how the software is structured, SaaS is the application of the perspective of how the software is applied, software can be used to use the SaaS SOA approach to users, Also brings loose coupling to SaaS systems, and I am confident that SOA and SaaS will be well integrated in the near future to guide our development and application.