Introducing BPEL Concepts Oracle BPEL Process Manager

What Is BPEL? BPEL is: A markup language for composing a set of discrete services into an end-to-end process flow A mechanism for asynchronous interactions, parallel processing, and exception management... BPEL source SalesDB Router Billing

The BPEL Standard Some of the key foundation points of BPEL are: Asynchrony: Asynchronous interactions Flow coordination: Parallel flow of execution Exception management: Handling exceptions Duplicate number! SalesDB End Router Billing Start

Orchestrating Services with BPEL

Developing a BPEL Service A BPEL process is a service that may be invoked by other services. A BPEL service can be developed by: –Visual design tool — Oracle BPEL Designer plug-in –Editing the BPEL elements with a text editor Using Oracle BPEL Designer templates, you can start to create the BPEL services for: –A synchronous service –An asynchronous service –An empty service –User Defined Template

Invoking a Synchronous Service A synchronous service: Processes input Returns an immediate response Example: Invoking a credit rating Web service Transport (SOAP over HTTP) CreditRatingRequestMessage CreditRatingResponseMessage Web service Functional building block process returns credit rating. Self-described interface (WSDL)

Invoking an Asynchronous Service Asynchronous services: Are initiated by using an Invoke activity Can take any amount of time to complete Uses WS-Addressing information to call back a BPEL process Receive activity waiting for the response Rapid Distributors asynchronous Web service [2:05] receive [2:06] process… [2:22] callback Initiate port Callback port Initiate onResult callback

BPEL Variables Communicate data between services and activities used by a BPEL processes Have a built-in data, element, or message type –Element types are defined as XML schemas. –The message type structure is defined as an XML schema element type and is defined in WSDL. BPEL process XML schema WSDL Global variable … Message type Defined as Defined in Scope Local variable

BPEL process Partner Links and Service Invocation Invoking a BPEL process requires: A that encapsulates a definition of how to access a service by using WSDL An activity to initiate an operation provided by the service Client Service Invoke Service description (WSDL) WSIL browser Partner link Partner link

Lab 3: Creating a BPEL Process for Orchestration