Web Service Orchestration

Learn about Web Service Orchestration

what do web services aim to do

expose computational elements onto the web alongside data using simple protocols

program built by composition 1

take atomic services

program built by composition 2

wire together their inputs and outputs

program built by composition 3

iterate across sets

two approaches

command and control (orchestration) and decentralised (choreography)

command and control (orchestration)

allow a process to be described, tell each component service what to do, when, and to what

decentralised (choregraphy)

provide a language whereby services can cooperate autonomously

orchestration

an executable business process that can interact with internal and external web services at the mssage level

orchestration vs choreography

orchestration takes place from the perspective of some business stakeholder and choreograhy is about the services themselves building the process

architecture

encapsulate the workflow as a service itself where all the individual functions are provided by components

general requirements for orchestration 1

flexibility in interacting with services

general requirements for orchestration 2

structure - mirror workflow

general requirements for orchestration 3

composition - allow processes to use other processes transparently

general requirements for orchestration 4

state - maintain at least the notion of a process being followed, different from any other

general requirements for orchestration 5

error management

additional requirements for orchestration 1

full integration with web and web services at all conceptual levels

additional requirements for orchestration 2

simplicity, no need to formulate a complex syntax

additional requirements for orchestration 3

no need to actually write code