XML Metadata Interchange (XMI)

Copyright 1999, UNISYS Corporation Slide 1

XML Metadata Interchange (XMI)From UML Object Models toXML DTDs and Documents

OMG TC MeetingNovember 15-18 ; Cambridge

Sridhar IyengarUnisys Fellow

Unisys [email protected]

UnisysWe eat, sleep and drink this stuff (metadata)!


Topics CoveredTopics Covered

■ Introduction

■ OMG Modeling and Metadata Architecture– XMI, UML and MOF– Applied to Enterprise Application Development,

CORBA Components, Data Warehousing– Coming : Document Management, Business

Objects, Vertical Domains, EAI■ How can OMG (across various groups), OAG,

OASIS work together


■ Modeling Technologies– Modeling OMG UML, (Meta)Modeling OMG MOF

■ Metadata Integration Technologies– W3C XML , OMG XMI , OMG MOF

■ Information/Content Models, Meta Models, DTDs– OMG UML, Data Warehousing CWM, CORBA CCM,

Document Management, MDC OIM, KnowledgeManagement, OMG EAI WG, .. OMG Vertical domains,OAG, OASIS, BizTalk..

■ Middleware Infrastructure– CORBA/CCM, EJB, COM+, HTTP, XML, SOAP...

Model & Metadata basedModel & Metadata basedIntegration : Sample InitiativesIntegration : Sample Initiatives


OMG OverviewOMG Overview

• About 800 member companies, world’s largest softwareconsortium.

• Founded April 1989.

• Small staff (27 full time); no internal development. InU.S.A., Germany, Japan, U.K, Australia, India.

• Started the Object World series of conferences, whichcontinues as COMDEX/Enterprise.

• Dedicated to creating and popularizing object-orientedstandards for application integration and development


OMG History : Major EventsOMG History : Major Events

■ 1989 OMA Vision & Architecture

■ 1991 CORBA 1.0

■ 1995 CORBA 2.0 IIOP - CORBAInteroperabilityDemo

■ 1997 MOF and UML Adopted, Domainspecs begin to be adopted

■ 1998 XMI Specification & Demo

■ 1999 XMI, CORBA 3.0 Components

■ 2000 CWM, XML/CORBA, EAI...


UMLModel & Design

MOFManage &Discover

XMLeXchange

XMIFramework

OMG Metadata SummaryOMG Metadata Summary

UMLCWM

CCMEAI?

DTDsDocumentsSchemas*

* Target XMI 1.2


The Unisys Application Life CycleThe Unisys Application Life Cycle

Architecture Centric, Business driven,Iterative and Incremental

Work In Progress!

Discovery andTransformation

BusinessRequirem

entsModeling

ModelingArchitecture,

Object, Data…

AddBusiness

Logic

Build /WrapIntegrate

Components

Assemble& Test

Components

Configure&Deploy

Components

Models, Metadata, Components, Middleware

Manage

Components

ComponentRuntimes

(EJB, CCM..)

Acquired

Components

Short Cut!

Rigorous


Object Services

MetaModels (UML, CCM, CWM…)

Tools, Applications, Repositories, Registries

XML Metadata Interchange (XMI)Meta Object Facility (MOF)

Internet JavaCORBACORBA/COM Interworking

OMG Metadata and ModelingOMG Metadata and ModelingArchitectureArchitecture


Iyengar (c) 1995, Unisys

RepositoriesToolsApplications

Repository Common Facility

APIs APIs

Object Services (Naming, Transactions…)

CORBA, Internet,...

MOF XMI UML, CWM

OMG OMA ArchitectureOMG OMA Architectureand and Metadata RepositoriesMetadata Repositories

InformationMetaModels


A UML rendering of the OMAA UML rendering of the OMA

Object Management Achitecture (With UML/MOF/XMI) using the UML Notation (c) 1999, Unisys Corporation (Iyengar99)

CORBA ORB CORE, IIOP Engine...<<Subsystem>>

Applications,Tools, Repositories

<<Subsystem>>

Business Domain Frameworks (Air Traffic, Financial...)

<<Subsystem>>

Horizontal TechnologyFrameworks (UML, MOF, XMI...)

<<Metadata/Models>>

Object Services(Transactions, Security)

<<Subsystem>>

Interface, Component, MetaObject Repositories

<<Subsystem>>

Application Management Frameworks

<<Subsystem>>


OMG Development/MetadataOMG Development/MetadataEnvironmentEnvironment

UML Modeling Tools

<<Subsystem>>

MOF Repositories

<<Subsystem>>

CORBA ORB CORE, IIOP Engine, Java/IDL, COM/CORBA...

<<Subsystem>>

(from OMG Object Management Architecture (MOF/UML/XMI))

UML Repositories

<<Subsystem>>

CWM Warehouses

<<Subsystem>>Component Repositories

<<Subsystem>>

Java/C++ IDE's

Component Assembly Tools

Component Management Tools

XMI Framework

<<OMG Metadata>>

OMG Metadata Architecture showing use of CORBA or XMI (c) 1999, Unisys (Iyengar99)


OMG - OMG - Modeling and MetadataModeling and MetadataStandardsStandards

■ Object Analysis & Design Facility : UnifiedModeling Language (UML)

■ Model driven Metadata Management : MetaObject Facility (MOF)

■ Stream based Model Interchange Format : XMLMetadata Interchange (XMI)

■ Data Warehouse Management : CommonWarehouse Metamodel (CWM*)

■ Business Objects : Business Object Initiative(BOI*)

*In development


User Objects Layer (M0)

Model Layer(M1)

Metamodel Layer(M2)

Meta-Metamodel Layer (M3)

<Acme_Software_Share 98789>, 654.56, sell_limit_order, <Stock_Quote_Svr 32123>

StockShare, askPrice, sellLimitOrder, StockQuoteServer[Models, BODs, CBOs..]

UML::Class,Attribute, Operation, Component[UML, CWM, EAI…]

MOF::Class, MOF::Attribute[MOF]

Four Layer MetamodelingFour Layer MetamodelingArchitectureArchitecture


MOF OverviewMOF Overview

■ Foundation for OMG repository (metadata) architecture– Defines metamodels starting with the UML

– Provides generic meta-object interfaces (common toMOF and all MOF defined Meta-models...)

– Provides MOF-IDL mapping to automate generation ofconcrete object interfaces for specific metamodels

– Provides MOF-XML mappings to automate generationof XML DTDs and Documents (XMI specification)

– Can also be used with COM using COM/CORBAInteroperability software

■ MOF uses UML for (meta)modeling


M O F 1.1 Reflec t ive< < C O RB A ID L M odule> >

MO F M odel< < OM G M eta -m etam odel> >

M O F F ac ility

Discover &Manipulatemetadata

Model usingUML/MOFprecisely

Find and ManageMetadata

Repositories

MOF ArchitectureMOF Architecture


MOF ModelMOF Model (short for MOF(short for MOF meta meta-metamodel)-metamodel)

■ Shares the UML core concepts– Behavioral extensions (operations and constraints) added

for repository/metaobject manipulation

■ Intentionally not ‘thin’ to support betterintegration/alignment with UML

■ Defined using UML notation diagram,constraints (OCL) and textual description– Self describing; MOF IDL, DTD generated from MOF

■ Interfaces used to create and manipulate MOFcompliant metamodels and models


OMG MOF 1.1/1.3 ModelOMG MOF 1.1/1.3 Model

ConstraintNamespace

Package

GeneralizableElement

0..*

0..*+supertype

{ordered}0..*

+subtype

0..*

Generalizes

Classifier

Class AssociationDataType

Feature

BehavioralFeature StructuralFeature

Operation

AssociationEnd

Reference

0..*

1

+referent0..*

+referencedEnd1

RefersTo

MofAttribute

ModelElement

0..*0..1

+containedElement

{ordered}

0..*+container

0..1

Contains

0..*

1..*

0..*

+constrainedElement

1..*Constrains


MOF/UML ToolsMOF/UML ToolsInteroperability OptionsInteroperability Options

ObjectAnalysis &

Design(UML)Facility

Tool/App

MetaObject FacilityReflective

Tool/App

Intermediate Stream/File (XML)

Model TransferDTD Generation (XMI)

MOF/Repository

Model Access

readwrite

Unisys/IBM et al proposal


UML 1.3 : All DiagramsUML 1.3 : All Diagrams

M o d e l_ M a n a g e m e n t

(fro m U M L )

F o u n d a t io n

(fro m U M L )

B e h a vio ra l_ E le m e n ts

(fro m U M L )

U s e _ C a s e s

(fro m B e h a vio ra l_ E le m e n t s )

S t a te _ M a c h in e s


C o l l a b ora ti o ns


C o m m o n _ B e h a vio r


A c t iv it y _ G ra p h s

( fro m B e h a v io ra l _E le m e n t s )

C o r e

(fro m F o u n d a t io n )

D a t a _ Ty p e s


E x t en s i on _M e c h a n is m s


Model businessprocesses

Model businessdata/structures


Overview of XMIOverview of XMIXML Metadata InterchangeXML Metadata Interchange

■ Use W3C eXtensible Markup Language (XML)for the transfer syntax and interchange format– Specify XML Document Type Definitions (DTD) to

enable transfer and verification of • MOF based metamodels (using MOF DTD)

• UML based models (using UML DTD), etc.

■ Specify a precise MOF (UML subset) to XMLmapping– Use of OCL to specify stream production rules

– Allows interchange of any MOF based metamodel

– Enables automatic generation of DTDs

■ Unisys, IBM,Oracle, Platinum, DSTC and others


Open Metadata Interchan ge with XMI

XMIDevelopment

T ools

ReportsDatabaseS chema

DesignS oftwareAssets

R epository

App2

App4App5

App1

App6 App3

vs

6 bridges written by 6 vendors. N*N-N = 30 bridges writtenby N = 6 vendors.Versioning issues.


XML Streams (Models) (Many - based on each metamodel DTD)

XML DTD (MetaModels) (1 per metamodel used for validation)

CWM*DTD

UML 1.1DTD

MOF 1.1DTD

XMI XMI SimplifiedSimplifiedOMG Documents :OMG Documents : ad/98-10-05, ad/98-10-06ad/98-10-05, ad/98-10-06

XMLSyntax and Encoding

MOFMetadata Definitions

& Management

XMI

UMLMetamodel

Analysis & Design

UML

UML Models UML

CWM Models* UML

MOF MetaModels

Validate


How to use XMIHow to use XMI

■ Define the domain or technology specific model– Middleware models are usually called metamodels by

OMG

– Use UML - only knowledge of Class modeling needed toget started

■ Export model to XMI processor which generates– XML DTDs for the specific (meta) model

– XML documents that conform to the DTD

■ Manage the Models, DTDs and documents in aMOF/XMI compliant distributed repository


UML 1.3/MOF/XMI GenerationUML 1.3/MOF/XMI Generation

MOF --> C ORB A ID L Mapping in MOF 1.3 spec

Unisys ID LGen

UML 1.3 Log ica l Metam odel

< < M odel> >

UML 1.3 P hysica l M etam odel

< < M odel> >

A pply UML to MOF Transformation Rulesto produce physica l metamodel

UM L1.3 X ML D TD< < XM I DTD> >

UML 1.3MOF C ORB A ID L

< < M OF --> IDL> >

UML 1.3X ML D ocument

< < XM L Doc um ent> >

MOF - -> X M L Mapping in XM I 1 .0 S pec

IB M & Unisys DTD Gen

MOF --> X M L documnt Mapping in X MI 1 .0 S pec

Unisys X MLGen


<!ELEMENT Class (name, visibility, isRoot, isLeaf, isAbstract, isActive,

XMI.extension*,

constraint*, requirement*, provision*, stereotype*,

elementReference*, collaboration*, partition?,

template?, view*, presentation*,

namespace?, behavior*, binding?

implementation*, generalization*, specialization*,

parameter*, structuralFeature*, specification*,

associationEnd*, participant*, createAction*,

instance*, classifierRole*, realization*,

classifierInState*, taggedValue*, ownedElement*,

feature*)?>

<!ATTLIST Class XMI.element.att; XMI.link.att;>

<!ELEMENT name (#PCDATA | XMI.reference)*>

<!ELEMENT feature (Feature| StructuralFeature| Attribute| BehavioralFeature|Operation| Method Reception)*>

...

UML 1.1 XML DTD SubsetUML 1.1 XML DTD Subset

<Model xmi.id="a1"> <name>Business</name><visibilityxmi.value="public"/>

<ownedElement><Class xmi. id="a7"><name>Customer</name>

<feature><Attribute><name>id</name>

<multiplicity><XMI.field>1</ XMI.field> < XMI.field>1</ XMI.field></multiplicity>

<type>< DataType href=”|a247"/></type></Attribute><Operation><name>update</name>

<scope xmi.value="instance"/></Operation>

</feature></Class>

</ownedElement></Model>

XMI 1.0 - XML Document SampleXMI 1.0 - XML Document Sample


XMI 1.1 OverviewXMI 1.1 Overview

■ Addresses verbosity issues of XMI 1.0

■ Incorporates XML namespaces

■ Readability significantly improved


XMI XMI for Application Developmentfor Application DevelopmentOMG November 98 DemoOMG November 98 Demo

IBMVisualAge

Select

UnisysUREP

OracleRepository

RoseDTDGen

Enterprise

MOFDTDGen

RationalRose

SelectEnterprise

OracleDesigner

XMI

XMIXMI

XMI

XMI

XMIXMI XMI

XMI

VATC

WebSphere

VA Java

Non-XMIRepositories

XMI


OMG Common WarehouseOMG Common WarehouseMetaModelMetaModel

■ Scope– Data Warehouse lifecycle metadata management

■ Initial submission : IBM, Unisys, NCR, Hyperion,Oracle, Genesis, UBS, Dimension EDI...– Metamodel - Single logical & physical!

– Generated XML DTDs

– Generated MOF - IDL mappings

– Generated XML document

■ For final submissions– Improve based on feedback, vendor specific

metamodels, well formedness rules, demos


WarehouseProcess

WarehouseOperation

Transformation OLAP

XMLRecord-Oriented

MDDBRelational

CWMFoundationWarehouseDeployment

UML 1.3(Foundation, Behavioral_Elements, Model_Management)

WarehouseManagement

WarehouseManagement

Data Resources

DataAnalysis

Object-Oriented(UML)

CWM OverviewCWM OverviewCommon Warehouse MetamodelCommon Warehouse Metamodel

Foundation


XML(f rom L ogi cal Vi ew)

CW MFo unda ti on(from Lo g ical View)

Re la tiona l(from Lo g ical View)

RecordOriente d(from Lo g ical View)

Ola p(fro m Log ical View)

Tra nsform a tion(from Lo g ical View)

W a rehouseProce ss(from Lo g ical View)

MDDB(fro m Lo g ica l Vie w)

W a rehouseDeploym e nt(fro m Lo g ica l Vie w)

W a rehouseOpera tion(fro m Lo g ical View)

CWM MetaModel ArchitectureCWM MetaModel Architecture


XMI for DatawarehousingXMI for DatawarehousingNovember 1999 OMG DemoNovember 1999 OMG Demo


SQLDataType

SQLSimpleType

characterMaximumLength : IntegercharacterOctetLength : IntegernumericPrecision : IntegernumericPrecisionRadix : IntegernumericScale : IntegerdateTimePrecision : Integer

SQLDistinctType

ColumnSet

Columnprecision : Integerscale : IntegerisNullable : NullableType 0..* 1

+/structuralFeature

0..*

+/type

10..*0..1

+/feature

{ordered}0..*

+/owner

0..1

TableisSystem : Boolean SQLQuery

BaseTable

isTemporary : BooleantemporaryScope : String

View

isReadOnly : BooleancheckOption : Boolean

CWM Relational -- Tables, columns, and data types

CWM Relational :CWM Relational : Tables & Columns Tables & Columns


ModelElement(from C or e)

Cl ass(from Cor e)

FixedOffsetField

offset : IntegeroffsetUnitBits : Integer

Package(from Model_Management)

FieldValueCondition

value : ExpressionField

*1

valueCondition

*1

Classifier(from Core)

Attribute(from Core)

1

*type

1 structu ral Featu re

*

Group

1

*

/namespace

1

/ElementOwnership

/ownedElement

*

Record File

Record

<<0..1>> fieldDelimiter : String<<0..1>> recordDelimiter : StringisFixedWidth : BooleanisSelfDescribing : Boolean<<0..1>> skipRecords : Integer<<0..1>> textDelimiter : String<<0..1>> formatName : String

1

*

/namespace1 /ownedElement

*/ElementOwnership

*

*

+file*

+record*

{ordered}

RecordToFile

CWM Record-Oriented

CWM : Record OrientedCWM : Record Oriented


MOF, UML and XMLMOF, UML and XML IntegrationIntegration : :SuggestionsSuggestions

■ Use UML for analysis and design of metamodels (these aremodels after all!)

■ Define and manage metamodels/profiles using the MOF– Use UML based modeling tools, or MOF interfaces (normative) or

XMI

– Enables life cycle meta data interoperability and design reuseacross metamodels

– Relationships and Subtyping across metamodels supported by theMOF

■ Use XML for exchanging metadata via OMG XMI

■ Use MOF-IDL mappings for concrete IDL interfaces tometamodels

■ Inherit MOF Reflective interfaces for interoperable metaobjects across meta-models


Importance of (Meta)modelingImportance of (Meta)modeling■ Provides a regular and rigorous infrastructure at a

higher level of abstraction■ Furnishes an architectural basis for extensions and

evolution of software■ Facilitates alignment with other standards that use a

metamodel architecture– Potentially eliminate or evolve redundant standards (eg: CDIF

now endorses XMI)

■ Supports interoperability and integration acrossdomains at the semantic level

■ Use UML to design metamodels and models, MOFto implement and manage them and XMI tointerchange them over the Internet


Lessons LearnedLessons Learned

■ Tool Interoperability issues (vendor politics!)

■ Distributed systems are inherently more complex

■ Coarse VS Fine grained metadata access– Don’t use fine grained interfaces over a network if you

need to manipluate lots of complex objects

■ Use XML/XMI for exchanging metadata acrossnetwork using standard DTDs for validation

■ Use fine grained interfaces (MOF, DOM, Java) ondesktop

■ Replication and Versioning issues

■ Limitations of current standards


UML CORBACWM - DataWarehouse

BusinessObjects

Financial Transportation Simulation Life Sciences

ElectronicCommerce

Telecom Manufacturing Utility

Domains(Soon)

Platform(Now)

OMG use of UML, MOF and XMIOMG use of UML, MOF and XMI


OMG Use of UML/XMI/MOFOMG Use of UML/XMI/MOFfor EAIfor EAI

■ These technologies address modeling, interchangeand metadata management for various problemdomains

■ EAI/IAI have to solve the problem of managing thecomplexity of heterogenous application integration

■ Work on UML profile for Messaging and EAI RFP isin progress– Integration with UML for modeling business processes,

document structures

– XMI for metadata

– XML (potentially XMI) for data : Send issues to XMI RTF


Extending XML PossibilitiesExtending XML Possibilities

Hand coded integration

Application Integration Tools

Semantic XMI Integration

Component API Integration

Using XML is the firstreal opportunity toallow applications tobe connectedwithout excessivesupport fromsystems integratorand domain experts.

The biggest benefit isspeed of deliverywhich is by far thecritical issue foreBusinessenablement.

XML Integration

Leve

l of A

bstr

actio

n

Power of UML, MOF and XMI frameworks


OMG and OAG OpportunityOMG and OAG Opportunity

■ OAG has a development process that is movingtowards UML– Use of OMG UML for modeling and design process

– Use of XMI for DTD (soon Schema) generation

– Use of XMI for model/document interchange

– Use of MOF/XMI for metadata repository interoperability

■ OMG is developing domain specifications and hasjust started an EAI Working Group– Use of OAG BODs by OMG?

– Use of OMG domain specs (after UML and XML’isation)by OAG?

■ OMG has established OASIS liasion


UMLModel & Design

MOFManage &Discover

XMLeXchange

XMIFramework

OMG Metadata SummaryOMG Metadata Summary

UMLCWM

CCMEAI?

DTDsDocumentsSchemas*

* Target XMI 1.2


Concluding ThoughtsConcluding Thoughts

■ Ensuring a unified distributed meta objectarchitecture is key to solving the heterogeneousintegration problem

■ Most customers have and will continue to havecomponents and information from multiplesources that need integration

■ CORBA/EJB, DCOM/ActiveX, MOF/XMI(Metadata), UML (Modeling) need to worktogether with the content (business models,BODS…)

■ Modeling and Metadata matters - Master it : Use itin your domain


References & further readingReferences & further reading

■ Object Oriented Strategies, Dec 1995, 1998 - OO Repositories : PaulHarmon

■ Implementing a Corporate Repository, Adrienne Tannenbaum (Wiley)

■ Unisys Repository Information Model Technical Overview– http://www.unisys.com/Products/urep, follow links to documents

■ Common Object Request Broker Architecture 2.0, March 1995

■ OMG Common Facilities RFI #3 - Repositories

■ Unisys Response to RFI#3, OMG TC document tc/95-11-05

■ OMG Object Analysis & Design RFP ad/96-05-01

■ OMG Common Facilities RFP 5 - Meta Object Facility cf/96-05-02

■ Unisys et al OMG Meta Object Facility Response, ad/97-08-14,15

■ Rational et al OMG OADF (UML) Response , ad/97-08-10

■ Unisys et al XML Metadata Interchange (XMI) proposal, ad/98-10-05, 06

■ www.marketplace.unisys.com/urep; www.ibm.com/ad;www.microsoft.com

Unisys and UREP are registered trademarks of UnisysUnisys and UREP are registered trademarks of UnisysCorporation.Corporation.

OMG is a registered trademark, and ORB, OMG IDL andOMG is a registered trademark, and ORB, OMG IDL andCORBA and CORBA are trademarks of Object ManagementCORBA and CORBA are trademarks of Object ManagementGroup, Inc.Group, Inc.

OLE & COM are trademarks of Microsoft Corp.OLE & COM are trademarks of Microsoft Corp.

All other trademarks owned by respective organizationsAll other trademarks owned by respective organizations

XML Metadata Interchange (XMI)

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