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MDA for Web Services

Applying Model Driven Architecture to Web Services

Document webserv/2002-04-05

Copyright © 2000-2002, Data Access Technologies, Inc.

Problem Space

Integration NightmareInfrastructure, Version & Vendor

lock-inComplex, divergent and manual

development and deployment processes


Goals

A scalable and robust enterprise architecture Loosely coupled enterprise components Enable rapid provisioning of business solutions

Simple, reproducible processes supporting reuse Technology & vendor independence Enable the integration and collaboration of

multiple; Business units (internal and external) Customers Suppliers Systems Technologies


Model DrivenDevelopment

Solution Triad

Service BasedArchitecture

Standards

Tooling & Infrastructure

Development Process

Components

WebServices

Corba

OMGECA

J2EE.NET


The new center

The strategic core of you systems must be the business itself

Only technology independent business focused models will survive the transience of technology and lock-in

These models can become part of your source code, driving enterprise applications

Enabler: Model Driven Architecture (MDA) with EDOC-ECA

Extreme ModelingExtreme Modeling

Collaboration and Web Services

Collaboration is the center of applying web services to core enterprise problems.

EDOC – Enterprise Collaboration Architecture

Provides the standard UML “PIM” profile suitable for enterprise application of web services


What is the Enterprise Collaboration Architecture?

ECA is a “profile of UML”, a way to use UML for a specific purpose - it is an OMG standard That purpose is modeling enterprise systems.

You can also think of this as a “modeling framework” for enterprise computing

ECA is part of the “Model Driven Architecture” (MDA) initiative of the OMG Using precise modeling techniques as part of the

development lifecycle to speed development and provide technology independence

ECA has been adopted by the OMG as part of the EDOC RFP.


WSDLWSDL&&

SoapSoap

Using MDA for WSDL

Mapping

“PIM”

“PSM”

Business FocusedBusiness FocusedECA ModelECA Model


Collaboration is Key

Collaboration is a key differentiation and key cost center (Healthcare Example) Customer Collaboration Claim processing Disputes Physician Collaboration Payer Collaboration Hospital Collaboration Broker Collaboration Government Collaboration Employee Collaboration Others...

The system integrates multiple

collaborations


AutomatedModel Driven Architecture

ProfileProfile(E.G. EDOC)(E.G. EDOC)

Framework &Framework &InfrastructureInfrastructure

(E.G. Web Services)(E.G. Web Services)

InfrastructureInfrastructureMappingMapping

(E.G. Web(E.G. WebServices)Services)

Mapping is tunedMapping is tunedto the infrastructureto the infrastructure

ToolsToolsProduce &Produce &IntegrateIntegrate

EnterpriseEnterpriseComponentsComponents

Business FocusedBusiness FocusedModel (UML)Model (UML)

Minimize and structuremanual implementation


Loose Coupling

Loose coupling is the ability for independent parts of systems to be built and evolve independently

Tightly coupled systems Prevent change (the next legacy system) Cause lock-in Become unmanageable Prevent reuse

Quality architecture is essential for loose coupling


Enterprise Components

Enterprise Components must be independent

While being able to interoperate with each other

Making the information system a lattice of cooperating components Open

Standards

OpenStandards

Ope

n

Stand

ards


Poor Monolithic ArchitecturePoor Monolithic Architecture

Traditional datasources

SQL DBMS &

Client/Server

BadThing

All business rules, data rules, application logic, technology and user interface code are contained here

The data goes here

MonolithicApplications

MonolithicApplicationsHTTP

WebBrowser

Making a monolithic webapplication doesn’t help!


HTTP Web ServerApplications

Enterprise ArchitectureEnterprise Architecture

SQL DBMS,Client/Server

& Legacy Applications

ClientApplications

Business and datarules go here

User interface andapplication logic gohere

The data goes here

EAI Applications &B2B E-Commerce

WebBrowser

Standard Middlewareconnects applications to components & components to components

XMLCorbaEJB

DCOMMQ

Supply Chain

EnterpriseComponents


What the infrastructurevendors would

have you do

Technology Independence

BusinessLogic

ComponentebXml

BusinessLogic

Component.NET

BusinessLogic

ComponentRosetaNet

BusinessLogic

ComponentEjb

Adapters

EJB

BusinessLogic

Component

ebXml

BizTalk

Rosetanet

Adapters

CICS

EJB

MQ

Corba


Typical Requirement

B2BBuyer

WebService Seller

BuyerWeb Page

HTML Seller

RedundantWork!


B2BBuyer

Multi-tier implementation

BuyerWeb Page

HTMLBuyerProxy

WebService Seller

Could havemultiple

implementationsusing differenttechnologies

Could havemultiple

implementationsusing differenttechnologies


LegacySeller

Applications

Event Cloud

B2BBuyer

Multi-tier implementation

BuyerWeb Page

HTMLBuyerProxy

WebService Seller

EventEvent

Implementing sellerusing events

Understanding Collaborations


The Connected EnterpriseContent and Communication

AerialPhotos

DigitalMap

CensusData

HouseDrawings

PoliceRecords

PoliceDispatcher

Role


Multiple roles in a collaboration


Implementation

Net

Hardware

OperatingSystem

Framework,Middleware& Container

Roles to Systems

Interaction Path

Component in Role

Interaction(With Information)

Role

Collaboration

The Internet Computing Model

The technology model behind WSDL and ebXML and others


The Internet Computing Model

Collaboration of independent entities

Document exchange over internet technologies Large grain interactions

No shared infrastructure required *

Long lived business processes Business transactions

BusinessParty

BusinessParty

Portals


Requirements for the “ICM”

Contract of Collaboration Shared business semantics Meta-Model (EDOC-ECA) and

representation (I.E. XMI, ebXML-BPSS)

Shared Repository for Contracts (MOF, UDDI, ebXML)

Connectivity (middleware) which meets requirements of the contract

Implementation of each contract role providing connectivity (application server)

BusinessPartner

BusinessPartner

Repository

Contracts(Metadata)

Contract of collaboration can be mapped to the format of various technologies. (ebXML, Soap, .NET)

Instance Data


Two levels of interoperability

Instance data and interoperability

Metadata (contract) interoperability

BusinessPartner

BusinessPartner Bridge

Each can be transformed

PurchasingModel

.NETebXMLBPSS

ebXML Biztalk

Normal Form

Over Soap Over Soap


Drilling down – inside a role

The open domain should make no assumptions about the “inside” of a role.

Inside one role you frequently find more collaborating “parts” of the enterprise - the same model may be used

Until you get to system inside a managed domain Shared resources (DBMS) Common Management Frequently a legacy system

Inner RoleLegacy

InnerRole

Inner RoleDomain

Cust


Collaborative Business Semantics

Defined: The processes, information and contracts of interaction between collaborators within a community

Collaborative business semantics are a valuable long-term asset

Captures information and process Requires ownership and support Do not put this valuable asset in a (transient - one

size fits all) technology specific form Use technology independent models (MDA) Map to the technology of the day (E.G. DTD)


Generic web services

Generic web services is any set of technologies that can implement the internet computing model.

WSDL, ebXML, .NET…

Standards for Global Internet Computing

EDOCEDOCEDOCEDOC

SOAP

WSDL

XML

XML-Schema.NET BPML

XLANG


XML Standards

XML Schema & DTD Description and packaging of data

WSDL Specification a services, operations and flows

available via that service

Soap Basic messaging and packaging Extensions for Soap-RPC with WSDL May be extended to support collaborative

messaging


ECA as the normal form

EDOC-ECA

Web Services(WSDL)

ebXML(BPSS)

J2EE(Java RMI)

.NET

MOM(MQ-Series)

The standard way to model and tool for multiple

technologies

MDAMappings

English

EDOC Component Collaboration Architecture

The model of collaborative work


The Marketplace Example

Mechanics Are UsBuyer

Acme IndustriesSeller

GetItThere FreightShipper

Order

Conformation

Ship Req

Shipped

Shipped

PhysicalDelivery

Delivered

Status

ProcessComplete


The Seller’s Detail

Order

Conformation

Shipped

Ship Req

Shipped

Delivered

Order Processing

Shipping

Receivables

Event


The Community Process

Identify a “community process”, the roles and interactions in a collaboration

Buyer Seller

BuySell CommunityProcess

Buy Sell

Shipper

ShipDelivery

ShipDelivery

Protocol


Protocol OrderBT

OrderDenied

OrderConfirmationOrder

responderRoleSeller

initiatorRoleBuyer

Protocols

<<initiates>> Order

<<responds>> OrderDenied <<responds>> OrderConfirmation

Failure Success


Composition


ECA/WSDL mapping

ECA works well as a modeling framework for WSDL

How major concepts could map WSDL Port <-> ECA Port WSDL Operation <-> ECA Flow port (one way)

or Operation (Two way) WSDL Service <-> ECA Component WSDL Port type <-> ECA Protocol WSDL Message <-> ECA Document type


WSDL/ECA Differences

WSDL Adds Technology binding and endpoints

ECA adds Choreography, nested conversations,

two-way protocols, nested components.


Next steps

RFP Draft – “Web services for enterprise collaboration” Two way mapping between EDOC-ECA and

WSDL/Soap Draft available – discussion in “MARS”

Roadmap items to make web services more viable as enterprise infrastructure Security and reliability


Business Case· High level support for understanding and documenting collaborative business processes.

· Loose coupling between independent parties in a collaboration

· Tighter coupling in the software development life-cycle between design and implementation processes and artifacts.

· Consistency in the way WSDL is used to implement collaboration.

· A standard way to use UML for web services.

· Enhanced support for asynchronous interactions.

· Automation of the development process from design to implementation.

· A faster, more deterministic development processes.

· Ability to adapt to changing business requirements.

· Ability to adapt to multiple and changing infrastructure technologies.

· Full life-cycle tool support