As a hot technology, web services, how to apply to the company's IT system and business processes, and bring direct economic benefits to enterprises, have been highly concerned and respected by domestic and foreign enterprise managers. In the past two years, a technological architecture has emerged as the next generation of web services, which is SOA (Service-Oriented Architecture, facing service architecture). In 1996, Gartner raised SOA. In December 2002, Gartner proposed SOA is the "most important topic in the field of modern application development". It is also expected that SOA will become an absolute advantageous software engineering practice method. Mainstream companies should now understand and apply SOA development skills. Investment in terms of aspects.
Better support business processes
SOA is not a new thing. The IT organization has successfully established and implemented SOA applications for many years, BEA, IBM, and other manufacturers have seen its value and follow up. The goal of SOA is to make it become more flexible to realize real-time enterprises in response to the needs of business units, which is the vision target description of Gartner as SOA). BEA's CIO RHONDA has made it possible to convert BEA IT infrastructure to SOA as early as June 2001, and increase development efficiency, speed up development speed, and reduce development speed and reduce skills. Good results have made good results.
SOA is a specification for designing, development, application, and managing dispersed logic (service) units in computing environments. This definition determines the broadness of SOA. SOA requires developers to design application software from the perspective of service integration, even if the interests do not immediately appear. SOA requires developers to surpass application software and consider multiplexing existing services, or check how to make services are reused. SOA encourages the use of alternative technologies and methods (such as message mechanisms), and archives the service to archite the application. After appropriate framework, the application of this message mechanism allows companies to make rapid market conditions for changes within the time of business environment permits by adjusting the original service model rather than being forced to carry out large-scale new application code. the response to.
SOA is not just a methodology of development - it also contains management. For example, after using SOA, managers can easily manage these enterprise applications on the service platform, not to manage a single application module. The principle is that through the mutual call between the analysis, SOA makes the company's management personnel to get it. What is the reason, which business logic executed data information, which helps enterprise management or application architect iteration Optimize their business processes, application systems.
One central idea of SOA is to make the company to get rid of the binding of technology-oriented solutions, and easily respond to changes in business services and development. [L1] A single application in an enterprise environment is unable to include business users (various) needs, even a large ERP solution, still cannot meet this demand in the expansion, change, and respond to the market Business users can only develop new applications, extend existing applications to support their existing business needs. By putting attention on services, the application can focus on providing a more abundant, powerful business process. As a result, SOA-based enterprise applications typically reflect the combination of business models more truly. Service is from the perspective of business processes - this is from top down. This angle is the opposite of the business perspective driven by the available technology. The advantage of the service is clear: they will be combined with the business process, so the business model can be more accurately supported to better support business processes. On the contrary, we can see the application-centric enterprise application model forcing business users to limit their capabilities to the ability of the application.
Enterprise Process is air flowing through the enterprise framework, which gives components in the business model to life and define their relationships more clearly. The process defines a special method for interacting with the business model. For example, accounting may be a component of a corporate service system - but send invoices to customers but a business process. Services are defined to support business processes, so throughout the process is always: the assembly operations of various service components during process and logic implementation. Understanding business processes is the key to customization services. Integrates integration of corporate business
Traditional application integration methods (point-to-point integration, enterprise messaging bus, or middleware integration (EAI), business-based integration) are complex, expensive, and not flexible. These integrated methods are difficult to quickly adapt to demand for the continuous production of changes in corporate modern business. Application development and integration based on service architecture (SOA) can be well solved many of the problems.
SOA describes a complete development model to help client applications are connected to the service. These modes customize a series of mechanisms for describing services, notifications, and discovery services, communicating with services.
Unlike traditional application integration methods, all modes around the service are implemented in standard-based technologies. Most of the communication middleware systems such as RPC, CORBA, DCOM, EJB and RMI, are the same. However, their implementation is not perfect, there is always a problem in trade-off interactivity and standard customized acceptability. SOA tries to exclude these defects. Because almost all communication middleware systems have fixed processing modes, such as RPC functions, CORBA objects, and more. However, the service can be defined as a function, but also simultaneously defined an object, application, etc. This allows SOA to adapt to any existing system and make the system do not have to deliberately follow any special customization when integrating.
SOA helps enterprise information systems to migrate to the "Leave-And-Layer" architecture, which means that the system can provide Web service interfaces outside the system without making modifications to existing enterprise systems, because they have been The application layer that provides a web service interface has been packaged, so SOA can quickly convert system and applications to services without modifying existing system architectures. SOA not only covers information from package applications, customized applications, and legacy systems, but also overrides features and data from IT architectures such as security, content management, search. Soa-based applications can be easily added from these basic service architecture, so SOA-based applications can respond faster to market changes, in order to make new functional applications in enterprise business units.
The figure below provides a high-level view of a business application based on service-based enterprise applications. The main difference between the traditional enterprise application integrated architecture is that the system uses standard-based services and includes process / data services, arrangements, and combinations. Standard service is an integration point between applications. Services and combinations of services add the flexibility, reuse and integration of services.
Illustration: Enterprise applications based on service integration
SOA service particle size
Services can be defined according to the number of data based on the service and transmitting and reception, such as fine-grained service, coarse granular service or combined service.
There are two related meanings in SOA services: how is the service implemented, service use and how much data or how much information is returned. The fine-grained service executes the smallest function, transmits and receives a small amount of data. The coarse granular service performs a large business function and exchanges more data.
The fine-grained service is used for serving or combined services, rather than being used directly by the terminal application. If the application is established using fine grain service, the application will have to call multiple services on the network, and there is less data on each service, and thus affect the overall system of system. So the user of the coarse particle size service cannot directly call the fine-grained service he use. However, since the coarse particle size service may use multiple fine-grained services, they cannot provide the safety and access control of the granular level.
The combined service can be assembled using a coarse particle size service and fine-grained service. The quantity of data is not the difference between coarse particle size services and combined services. Rough granular service example, such as creating new customers, the operation of this process is: You need to verify the customer through some external service verification, and create a customer record in the CRM application. The combined service example can be a new DSL line that requires a service call to verify the order, create or verify the customer, confirm the product inventory and assign resources for the data line. The figure below describes the different levels of the service particle size and the relationship between them.
Illustration: Service Particle Size
By a set of effective design and combined coarse granular services, business experts can effectively combine new business processes and applications.
SOA and Web services
SOA does not necessarily require a web service to achieve, and a web-based application is not meant to be a SOA architecture. The web service is only a typical typical service implementation, which is a component of the company SOA (non-essential components). SOA provides conceptual design patterns for service-based distributed systems. The Web service is a standard based on standard and economically affordable SOA. [l2]
SOA provides IT resources through the concept of such an important meaning in business, sharing, closing IT with the distance from the business. The service is higher than the components, functions, and the process, and often can find a concept or entity corresponding to directly, such as quotes, orders. The service breaks the barriers between IT systems, just like a company's departments, usually play a role of specific pairs or external services, but if they can effectively communicate with the language and text, they can communicate. Cooperate reached a bigger, higher goals.
With the trend of SOA and web services, it has brought the development method and concept of Composite Application, which is gradually applied to Portal (portal) and Integration. The application of the combined portal is the application provided by the Portal interface, often not really executing on the Portal server, but the web service is immediately grabbed, and then renders, and summarize the user of Portal. In terms of integration, a combined manner is used. Through the advanced tools, it is set to make the system to flexibly cooperate with the task adjustment, and different forms of series and collaboration of the services provided in Web service methods will be used to quickly deploy. In March 2004, BEA released an Enterprise Portal Rationalization, EPR. This strategy used to balance the SOA capability of BEA Weblogic Platform, helping customers have formed over the years with the best industry practices and industry experts. Scattered portal and web applications development.
If Web services such as Web services are the flesh and blood of SOA, then the correct service design concept and system running platform are SOA soul. SOA is trying to make IT faster and business services to provide elastic business services. From CIO to system analysts, need and business units, strategic partners have sufficient communication. CIO must recognize that the establishment of SOA will be a few years of commitment. The basic construction needs to be conducted in accordance with the class, and the model must be established between IT and various business units to support infrastructure and various business services. .
In the middle of the middle space, SOA architecture is increasingly a new focus for middleware software suppliers. Everyone wants to provide the best SOA technology to the competitors, and BEA is no exception. From a technical connection, the use of component technology will help SOA's further popularization, from the business, enterprise users require higher cost-effective applications, and SOA is just in this trend. At the end of May, on the Ninth Technical Annual Meeting Eworld 2004 in San Francisco, San Francisco, the global BEA technology elite will experience the SOA system on the SOA system on the SOA system on the scene on the scene. Design patterns and best practices, that is, how to build the technical guidelines for the SOA system, then these best technical practices will resequentize with BEA's developer site (headquarters: http://dev2dev.bea.com, China Developer Site: Http://dev2dev.bea.com.cn This is a global technical user, and the ultimate goal is to make not only a BEA customer, and it is a global enterprise user's information system to maximize the business value brought by SOA. .
