In following diagram client and service publishes their interface. Consumer will find particular service and communication between client and service starts
- Service Provider : Who develops and supplies services
- Service Consumer: Who uses the service
- Service broker/registry/rules : Facilitates advertising and discovery process
Business Rule is : For example driving license you are eligible at age 21
ESB – Enterprise service bus
In traditional approach, if you have six applications you need to have n(n-1)/2 connections.
ESB connect different applications
[From IBM Page Ref:3]
Figure the elements of an enterprise-wide SOA from the perspective of applications. Business processes are partly or fully supported by user interface applications and service applications. A step in a business process is either manual or is supported by a user interface application. User interface applications implement a lot of micro workflow, and they also consume services that implement business functionality.
In the service choreography layer, composite services are defined by means of a choreography language, such as BPEL (Business Process Execution Language). The choreography of composite services defines their flow and composition fromelemental services. The choreography layer should be supported by a choreography tool that allows graphical specification, such as IBM WebSphere® Business Integration Modeler and IBM Rational® Application Developer.
The elemental services, used by the service choreography layer and also by user interface applications, are implemented by service applications. In turn, the service implementations might call other services, often from other service applications.