EAI Platform Construction Based On SOA

With the development of Enterprise Information System, more and more applications are being used, and the interaction among the systems has become increasingly important. Since each system uses different technology, and being deployed on different operating systems, it is extremely difficult to integrate these systems. As the business interaction among enterprises has become increasingly frequent, more and more information needs to be integrated by information technology, which also caused the need for effective integration. This application integration needs to cross enterprise network, even internet, also taking in the firewall settings, the situation is very complicated.QiMing IT Company, for example, the several Information Systems which all belong to it also has a lot of needs that transferring information among themselves.such as BOM generated in the PDM system needs to be integrated into ERP and SCM system, the information of providers, contracts, price in SCM system need to be used in ERP system. The inventory information, financial information generated in ERP system need to be showed to vendors in SCM system.Most of the traditional method of integration is using synchronization technology in database layer, through the establishment of Materialized View or Trigger in databases to import data directly into databases in other systems, the shortcomings of this approach is that when the integration is in a cross-LAN way, the stability of network will be the point that determine the success of the integration. Another common way is using intermediary file, whether xml or csv format which according to the agreement of the integrator, the data transfer among different systems, and the shortcomings of this approach is lack of transaction control, and it is difficult to say whether the data file transmission is done. Both of the methods above are point-to-point integration approach, when new integration requirement arrives, it will be necessary to do a large number of modifications, and they did not sufficiently consider the network situation, they can work in LAN, but if integration occurs in WAN, it can not be resolved.Technically, Webservice become the ideal solution to integration among the systems, Webservice provides a distributed computing technology that is used on the internet or intranet through the use of the XML standard protocols and message formats to demonstrate commercial applications. Webservice uses XML and XML-based standards, such as SOAP, WSDL and UDDI. These technologies enable communications among applications can be independent of programming languages, operating systems and hardware platforms.Webservice satisfactorily resolved external interface-exposing problem in each of the application system, it can be good to shield all of the different technologies, the deployment of the different operating systems and different network environment.Webservice is a realization of SOA which is a coarse-grained, loosely coupled service structure. SOA is a collection of services, and the services communicate with others through standard communication interface that has been precisly defined. Interface is defined in a neutral approach, so it is independent of the hardware platform, operating system and programming language.This makes the services can communicate with each other in a unified and common way. Based on SOA and Webservice technology we can build an Enterprise Service Bus (ESB), ESB in the enterprise is based on the Enterprise Data Bus (EDB), it provides a service promulgating mechanism to promulgate services in different systems.Service is a kind of futher abstract of data,it shields the implementation details.So,data can be packaged into a variety of services , it could be WebService services, JMS, HTTP services, the ESB provides service management, intelligent routing services among the calls.Business Process Management Bus (EBPMB) directly reflects workflows among different information systems, it uses BPM technology to unite the workflows, combined with business processes RuleEngine technology to implement the intelligent running. Enterprise business processes correspond real processes in enterprises, it is the end-to-end business process management.Workflows inside an information system call the EBPMB service to pass on the data that have been handling in it, and the EBPMB carries the data to another information system. As a result, business process management bus directly reflects the value of the business, changes "process splits", saves processing time, and provide value-added IT infrastructure for the enterprise development.Now we come to the conclusion, enterprise data bus EDB, Enterprise Service Bus ESB and Business Process Management Bus EBPMB in the EAI platform constitute the "nerve trunk road" of entire enterprise IT systems, EAI platform discarded the original rigid structure, laid the IT foundation for sharing IT resources, building value-added IT infrastructure.