BPEL

Learn about BPEL

BPEL4WS

business process execution language for web services

bpel feature 1

business centric in its terminology

bpel feature 2

simple core based around structuring concepts but enough to link to “real” computing platforms

bpel architecture 1

a business process description is just an xml document

bpel architecture 2

uses wsdl for component interface specifications

bpel partners

named participants providing a well-defined service for the process that are required for the process to function

what does a process maintain

variables that capture and name data being exchanged, e.g., messages between components or internal state for the process

how does a process describe interactions 1

receive a message from a partner

how does a process describe interactions 2

reply to a received message

how does a process describe interactions 3

invoke another service

note on concurrency

a receive operation can accept a message for itself or spawn a new instance of the process to handle the request

why would business processes want to avoid strict synchronisation?

more robust to failures, allows the execution engine to schedule interactions

BPEL dataflow

take the invocations we need and the data they require to be completed. let the execution engine decide when to execute them depending on data availability

consequences of formatting BPEL as XML 1

doesn’t look like a programming language

consequences of formatting BPEL as XML 2

verbose

consequences of formatting BPEL as XML 3

not entirely consistent in its use of notation