Understanding of SOA and SaaS

Understanding of SOA and SaaS 1 , SOA ( service-oriented Architecture ): architecture of the polygon service. Understanding SOA from a business perspective: it is the old software system for some enterprises to re-use, to consolidate, and build a set of loosely coupled software systems, but also easy to combine the new software together to serve a system of enterprises. Enables the system to be more flexible and adaptable as the business changes. Understanding Soa:soa from a technical point of view is actually the further development of the system analysis design idea, its thought goes beyond the object concept, everything takes service as the core, and the service is composed of components, the component is a set of operations, and the operation corresponds to the program function of concrete implementation. Services are identified by the analysis of the business process model. Each service can implement several functions that are implemented by components rather than by operations. A component is a collection of calls to an operation and is the smallest unit of service functionality implementation, not the smallest unit of a program implementation. In the implementation, as long as the technology can provide services can realize SOA ideas, such as Web service, RMI, Remoting, CORBA, JMS, MQ, and even JSP, SERVLET, etc., in addition, through the Distributed transaction processing and distributed software-like Management to further improve it. But if you want to make these services more widely available, or to be recognized, and published on the Internet, then you have to follow certain rules. The criteria for this category are soap, Java API for xml-based RPC (Jax-RPCs), WSDL and WS-* specifications, and so on. In addition, it requires security, policy management, reliable messaging, and support for accounting systems.   ESB Concept: A new software object is added to the framework of the SOA architecture. This object is an enterprise service bus, an ESB, that uses many possible messaging protocols to take care of the proper control, flow, and possibly even the transmission of all messages between services. Although an ESB is not absolutely necessary, it is a component that is critical to properly managing your business processes in an SOA. The ESB itself can be a single engine, or even a distributed system of many peers and subordinate ESBs that work together to keep the SOA system running. Conceptually, it is the development of a storage-and-forwarding mechanism built from the early days of computer science concepts such as Message Queuing and distributed transaction computing.   SCA and SOD concepts: as service-oriented architectures evolve and mature, developers and architects face ever-increasing programming interfaces, transport protocols, data sources, and other details. Service Component Architecture (SCA) and Service Data Objects (SDO) can provide a single programming interface for a variety of services and data sources. 2 , SAAS ( Service as a software ): The service is softwareSaaS is not only a portal for users, but also other ways, such as providing APIs, providing WSDL, providing ....   , as long as the user wants the service to be able. SaaS permissions control, security issues can be relatively cumbersome, may involve multiple enterprises of different platforms, multiple databases, if the control of permissions, to ensure security. Data synchronization issues. The key is how many users are willing to chang this risk. 3. The relationship between SOA and SaaS:SaaS mainly refers to a software enterprise to provide software services to other enterprises. SOA is generally the foundation of enterprise content building system. SaaS focuses on the thinking of delivering services. SOA is focused on the realization of service thinking. 4 , the current market SOA the pattern:    There are already a lot of SOA products on the market, and SOA products in which IBM, BEA and JBoss are basically 80% of the market, but JBoss SOA is slower than IBM and BEA. But it represents the open source SOA product market, so there is a lot of potential, and many engineers and companies expect it is also very big. The SOA products and ideas of IBM and BEA are relatively early and have some successful projects. But these two products are large and expensive, but they do not affect its development, and many enterprises are assured that the product. In addition, IBM and BEA also teamed up to launch an SCA software, APACHE TUSCANY. This is one step ahead of open source software. So now the SOA market competition is extremely fierce. In addition to these three, Oracle has released its own SOA offerings and ideas.