面象服务的体系架构浅析25p课件

1、面向服务的体系架构(SOA) 日程什么是面向服务的体系架构SOA的价值构成SOA的技术如何构建SOA系统IBM的SOA工具与产品网格计算与SOA2一个组件模型将应用程序的不同功能单元（服务）通过这些服务之间定义良好的接口和契约联系起来。接口是采用中立的方式进行定义的，它应该独立于实现服务的硬件平台、操作系统和编程语言。构建在各种这样的系统中的服务可以以一种统一和通用的方式进行交互。 什么是面向服务的体系架构?3为什么采用面向服务的体系架构?A Service Oriented Architecture enables flexible connectivity of applications

2、or resources by Representing every application or resource as a service with a standardized interfaceEnabling them to exchange structured information (messages, documents, business objects)Mediating the message exchange through an Enterprise Service BusThis flexibility enables new and existing appli

3、cations to be easily and quickly combined to address changing business needs. The ability to easily combine/choreograph applications allows IT services to more readily reflect business processesThe SOA infrastructure is also used to facilitate the management of business performance and quality of se

4、rvice4Flexible Business ModelsTransformationBusiness Process OutsourcingMergers, Acquisitions & DivestituresFlexible IT ArchitectureRequiresComposableServicesSoftware Development IntegrationInfrastructureManagementComposableProcessesService Oriented Architecture (SOA)DevelopmentInfrastructureManagem

5、entSOA的价值: SOA实现可变的IT架构 5构成SOA的技术什么是服务服务调用服务的编排服务的发现6什么是服务?A well-defined, invokable unit of business functionAccesses business data or facilitates a change of business datafrom one valid and consistent state to another.Defined using explicit interfacesIndependent of service implementationsProvides

6、contract between service requestors and service providersInvokable through common communication protocolsProvides interoperability and location transparency.7服务描述Services are described using a standardized interface (metadata)Defines the service, its operations, and input and output parametersDefine

7、s how the service is reached and its locationInput and outputs may be simple parameters or XML documentsAn existing application can be given a service faadeThe faade (e.g. an EJB) is then described as the serviceWeb Services Description Language (WSDL) is the standard used to describe the service8服务

8、描述: WSDLWSDL (Web Services Description Language) is an XML document that describes a Service using a number of key elements:A Port Type defines what the service does, and is described by a number of operations. For each operation the data that it receives and sends is described by a MessageThe Bindi

9、ng defines how the service (as described by the Port Type) is invoked e.g. SOAP/HTTP, SOAP/JMS.The Port specifies the address where the service is located9服务调用Services interact by exchanging data over an Enterprise Service BusThe Enterprise Service Bus is a logical architectural constructProvides in

10、ter-connectivity servicesServices interact with each other based on the quality of service requirements of the individual transactionsESB connects and integrates an enterprises IT businessIn different locations, using different transports, across organizationsESB mediates service requests and respon

11、sesPerforms transformation and routingEnables connection type transparencyESB enables the use of multiple protocolse.g. SOAP/HTTP can be converted to SOAP/JMS and vice versa10企业服务总线(ESB) Central to the Workings of a Service Oriented ArchitectureTransport ServicesSynchronous/AsynchronousPersistent/No

12、n-persistentLoosely-coupled/Tightly-coupledEvent ServicesPublish and Subscribe Mediation ServicesRouting TransformationStandards BasedHTTP/HTTPS with option for WS-ReliableMessagingJMS, JAX-RPC, SOAPWS-Security, WS-Policy, WS-Addressing11服务的编排术Business processes are a set of activities carried out i

13、n a sequenceServices can be choreographed to implement a business processi.e. each step or activity in a business process is implemented by a serviceThe business process itself becomes a serviceService choreography is described by the Business Process Execution Language (BPEL)A standard proposed to

14、OASIS for process definitionService Choreography provides:Processes that combine applications and peopleTransactionality and compensationManipulation of process data12服务的发现A Service Registry or DirectoryPublishes service descriptionsFinds business, services and service interfacesUDDI is a standard f

15、or a registry web service (see UDDI.org)Service discovery may be at design time or run timeWebSphere Studio provides Web Services Explorer to publish and search UDDIUDDI Service entries contain URL of its WSDLA UDDI directory may be private to an enterpriseWSDL for services may be stored in local fi

16、les and directoriesESB mediations may be used to determine services location at run timeServiceRegistry13SOA 的服务栈SOA uses Web Services specifications to implement its featuresMany Web Services specifications are being standardizedIBM and other vendors have implemented these specifications, anticipat

17、ing the standardsThe Web Service function stack is rich and getting richer14如何构建SOA的系统Develop a service oriented mentalityEverything is a serviceUnderstand and define servicesGood service decomposition is the challengeRemember coarse granularitySome service implementations will exist, others will ne

18、ed to be createdDetermine service interfaces and interaction patternsWhat formats will be adopted for data exchange?What qualities of service will bound interactions?Where will mediation be required/appropriate?Define service orchestrations in terms of supported business processes Composite services

19、 will generally reflect business processes?What are the business processes?Business models in WebSphere BI Modeler can prove invaluable here 15采用 SOA 的四个层次 16实现单独的 Web 服务17面向服务的集成18企业范围内的 IT 转换 19Enterprise applicationsEnterprise dataData Access ServicesApplication Access ServicesIBM Software Offeri

20、ngs Monitoring ServicesIBM商务整合的参考架构Model, design, development, test toolsCommon Runtime InfrastructureWebSphere BI ModelerWebSphere BI MonitorWeb Services GatewayWebSphere BI Event/Message BrokerWebSphere MQWebSphere BI AdaptersDB2 Information Integrator ClassicWebSphere StudioDB2 Information Integr

21、atorWebSphere Business Integration Server WebSphere Business Integration Connect WebSphere Application ServerEnterprise Service BusProcessServicesCommunity Integration ServicesApplication ServicesInformation Services WebSphere Portal ServerUser Interaction Services20Professional ServicesNetworkOGSA EnabledStorageOGSA EnabledServersOGSA EnabledMessagingOGSA EnabledDirectoryOGSA EnabledFile SystemsOGSA EnabledDatabaseOGSA EnabledWorkflowOGSA EnabledSecurityOGSA EnabledWeb ServicesOGSI Open Grid Services InfrastructureGrid ServicesSystem Management SevicesOpen Grid Services Architectur