Emergence of cloud computing, software as a service (SaaS), service oriented architecture (SOA) and adoptable standards in open source development have changed the way enterprises establish application infrastructure and approach enterprise application integration (EAI). New advances in object generation methods have changed the landscape of application-to-application (A2A) and business-to-business (B2B) implementations and customizations. With separation between A2A and B2B disappearing, enterprises look at A2A and B2B as two sides of the same coin and try to find solutions that support both scenarios without compromising security or business process efficiency.
Our integration service approach is developed around clear business objectives, business process integration and collaborative strategies and remains flexible and responsive to changes in business.
Web services play a major role in our integration, which is one of the most commonly used patterns for enterprise and business-to-business application integration. Here we look at the support for web services provided by major platforms and function/method – oriented integration in the A2A space.
The first generation integration was achieved using custom code written in COBOL, C and C++; then with application programming interfaces (APIs) using concrete data structures followed by the remote procedure calls (RPCs) across the network. Enterprise application integration entered into the next phase with the arrival of common object request broker architecture (CORBA), Java remote method invocation (RMI) and distributed component object model (DCOM) with distributed middleware and distributed objects. Presently, message oriented middleware MOM and XML Web services using SOAP are the ubiquitous standard in application integration.
Business requirements, business process, application architecture and enterprise data integration policy dictate the usage of function/method oriented integration. Asynchronous message oriented architecture is very different from the state full synchronous function/method-oriented applications.
Primarily, function/method-oriented integration is making synchronous call from the client to server passing a request and getting a response as result where the structure of request and response are mutually agreed between the applications using the infrastructure to facilitate the communication of data across the network.
Web Services as Enabling Technology
Web services technology provides a standard mechanism for applications to publish and subscribe to software services over an intranet or the Internet. Client applications (Web service consumers) locate these services published by server applications (Web service providers) using Universal Discovery, Description, and Integration (UDDI). Web Services Description Language (WSDL) details the interface definition of the service. Request and response data are formatted as Extensible Markup Language (XML) documents based on Simple Object Access Protocol (SOAP)
With built-in support provided by major application development platforms for web services, a client call to web service will look like a normal method call, but the framework handles the task of translating the request to a SOAP request and sending it over the network and translating the SOAP response back to a format digestible by the application.
Platform, language boundaries and interoperability are not an issue since web services are built on HTTP protocol and uses XML to marshal data between client and server.
Advantages of web services over RPC and API oriented integration: