Transcript Oracle.ppt
What is SOA? • IT architecture for request - reply applications • Application functions are modularized and presented as services • Services are loosely coupled – Service interface is independent of the implementation SOA Slides © Raghu Kodali http://www.nejug.org/2005/include/SOA andWebServices.ppt Service-oriented architecture (SOA) definition “A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.” (http://www.service-architecture.com/web-services/articles/serviceoriented_architecture_soa_definition.html) • Many other definitions can be found Characteristics of SOA • Services have platform independent, self describing Composable interfaces (XML) • Messages are formally defined • Services can be discovered Interoperable SOA Re-Usable • Services have quality of service characteristics defined in policies Loosely • Services can be provided on Coupled any platform Why SOA? – The Cruel Reality Application Screen Scrape Sockets Download File Download File Application Message Queue Application Application Sockets Application ORB Transaction File Screen Scrape Transaction File CICS Gateway Application Screen Scrape RPC Message Application Transaction File Application Source: Gartner Message Transaction Queue File Application Screen Scrape Application CICS Gateway Message ORB APPC Download File Message Queue APPC RPC Why SOA? • • • • • Respond to business changes Address new needs with existing applications Unlock existing application investments Support new channels & complex interactions Support organic business Oracle Financials Standard Interface Custom Order Application Standard Interface New Web Application Standard Interface New Supply Chain Management Application (Business Process or Composite Application) Standard Interface Siebel CRM Standard Interface Mainframe HR Application Standard Interface .NET Inventory Application Anatomy of a Service New Service Service Consumer Wrapped Legacy Interface Proxy Composite Service Service Interface Service Implementation Service Communication • Communicate with messages • No knowledge about partner • Likely heterogeneous Service Consumers Service Producers Service Platform Service Consumers Service Reporting & Mgmt Service Rules & Config Service Interfaces and Service Implementations Control Change Service Delivery Bus Benefits of SOA • Better reuse – Build new client functionality on top of existing Business Services • Well defined interfaces – Make changes without affecting clients • Easier to maintain – Changes/Versions are not all-or-nothing • Better flexibility Services Communicate With Messages • Providing reliability and security to messages • Sending messages across consumers and producers • Service Orchestration Service Consumers Service Producers Basic Web Services Points to description UDDI Registry WSDL Finds Service Web Service Client (J2EE, .NET, PL/SQL …) Points to service Describes Service SOAP Invokes with XML Messages Web Service (J2EE, PL/SQL, .NET,C/C++, Legacy …)