knowledge enabled information and services science semantics in services dr. amit p. sheth,...

Knowledge Enabled Information and Services Science

Semantics in Services

Dr. Amit P. Sheth,Lexis-Nexis Eminent Scholar,

kno.e.sis center,Wright State University, Dayton, OH.


Outline

• Motivation

• SAWSDL

• Dynamic Configuration

• Event Identification


Motivation

• Evolution of business needs drives IT innovation

• Initial focus on automation led to workflow technology

• In order to facilitate efficient inter-organizational processes distributed computing paradigms were developed– CORBA, JMS, Web Services

• The current and future needs include:– Creating highly adaptive process that react to changing conditions

• Focus on real time events and data – RFID and ubiquitous devices– Have the ability to quickly collaborate with new partners– Aligning business goals and IT processes


Advantages of Semantics

• Reuse– Semantic descriptions of services to help find relevant services

• Interoperability – Beyond syntax to semantics (ontology based approach)

• Composition– Enable dynamic binding of partners

• Some degree of automation across process lifecycle – Process Configuration (Discovery and Constraint analysis)– Process Execution (Addressing run time heterogeneities like data

heterogeneities.)

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Semantics for SOA Lifecycle

• Data Semantics: The semantics of the data that is either the input to a service or that is the output of the service. – Eg. Annotated service input and output specification.

• Functional Semantics: The semantics of what the service offers, the interfaces and the operations in a service.– Eg. Annotated interface and operation specifications of a

service.• Non-Functional Semantics: The qualitative and the

quantitative non-functional aspects of a service and its operations are modeled using non-functional semantics. – Adding semantics to policy specifications such as WS-Policy

and WS-Agreement.• Execution Semantics: The semantics concerning the various

exceptions and the actions to adapt to these during service execution.– Modeling execution paths using task skeletons


SAWSDL: Semantic Annotations for WSDL


SAWSDL

• Semantic Annotations for WSDL– Adds semantics to service descriptions via model

references.– W3C Candidate Recommendation

• Offer an evolutionary and compatible upgrade of existing Web services standards

• Externalize the semantic domain models– agnostic to ontology representation languages.– reuse of existing domain models– allows annotation using multiple ontologies (same or different

domain)

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SAWSDL at a glance

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Ack: Jacek Kopecky


SAWSDL Example

…………<xs:element name= "processPurchaseOrderResponse" type="xs:stringwssem:modelReference="POOntology#OrderConfirmation"/></xs:schema></types><interface name="PurchaseOrder"><wssem:category name= “Electronics” taxonomyURI=http://www.naics.com/

taxonomyCode=”443112” />

<operation name="processPurchaseOrder” pattern=wsdl:in-outmodelReference = "rosetta:#RequestPurchaseOrder" >

<input messageLabel = ”processPurchaseOrderRequest"element="tns:processPurchaseOrderRequest"/><output messageLabel ="processPurchaseOrderResponse"element="processPurchaseOrderResponse"/>

<!—Precondition and effect are added as extensible elements on an operation><wssem:precondition name="ExistingAcctPrecond"wssem:modelReference="POOntology#AccountExists"><wssem:effect name="ItemReservedEffect"wssem:modelReference="POOntology#ItemReserved"/></operation></interface>

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Using modelReference and SchemaMapping

• modelReference at the complex type level– Typically used when specifying complex associations at leaf level is not possible– Allows for specification of a mapping function

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<complexType name="POAddress“wssem:modelReference="POOntology#Address” wssem:schemaMapping=”http://www.ibm.com/schemaMapping/POAddress.xq#input-doc=doc(“POAddress.xml”)”>

<all><element name="streetAddr1" type="string" /> <element name="streetAdd2" type="string" /> <element name="poBox" type="string" /><element name="city" type="string" /> <element name="zipCode" type="string" /><element name="state" type="string" /><element name="country" type="string" /><element name="recipientInstName" type="string" /> </all></complexType>

Address

xsd:string

xsd:string

xsd:string

OWL ontology

has_City

has_StreetAddress

has_Zip

WSDL complex type element

semantic match


Using modelReference and schemaMapping

• modelReference at the leaf levels– assumes a 1:1 correspondence between leaf elements and domain model

concepts

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<complexType name="POItem" >

<all>

<element name="dueDate" nillable="true" type="dateTime" wssem:modelReference=”POOntology#DueDate”/> <element name="qty" type="float" wssem:modelReference=”#POOntology#Quantity”/> <element name="EANCode" nillable="true" type="string" wssem:modelReference=”POOntology#ItemCode”/> <element name="itemDesc" nillable="true" type="string" wssem:modelReference=”POOntology#ItemDesc” />

</all>

</complexType>

Item

dueDate

ItemDesc

Quantity

OWL ontology

hasIemDesc

hasDueDate

hasQuantity



Representing mappings

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<complexType name="POAddress" wssem:schemaMapping=”http://www.ibm.com/schemaMapping/POAddress.xsl#input-doc=doc(“POAddress.xml”)”>

<all><element name="streetAddr1" type="string" /> <element name="streetAdd2" type="string" /> <element name="poBox" type="string" /><element name="city" type="string" /> <element name="zipCode" type="string" /><element name="state" type="string" /><element name="country" type="string" /><element name="recipientInstName" type="string" /> </all></complexType>

Address

xsd:string

xsd:string

xsd:string

OWL ontology

has_City

has_StreetAddress

has_Zip


.... <xsl:template match="/">

<POOntology:Address rdf:ID="Address1">

<POOntology:has_StreetAddress rdf:datatype="xs:string">

<xsl:value-of select="concat(POAddress/streetAddr1,POAddress/streetAddr2)"/>

</POOntology:has_StreetAddress >

<POOntology:has_City rdf:datatype="xs:string">

<xsl:value-of select="POAddress/city"/>

</POOntology:has_City>

<POOntology:has_State rdf:datatype="xs:string">

<xsl:value-of select="POAddress/state"/>

</POOntology:has_State>....

Mapping using XSLT


Configuration and Adaptation – Roadmap

Semantic Web Enablers

Ontologies: Specification of

conceptualization. Mode of capturing concepts and their relationships, etc.

OWL: Ontology Web Language

SWRL: Semantic Web Rule Language

Annotation/Representation

WSDL-S/SAWSDL (02-06)

Discovery (MWSDI / SSR)Mapping WSDL-S into UDDI

Constraint AnalysisSemantically Enhanced Policies/

SWAPS

Dynamic ExecutionExtenstions to SOA Middleware

and Runtime

WSDL

UDDI

WS-Policy, WS-Agreement

BPEL Engines (BPWS4J,

ActiveBPEL)

BPELComposition

Planning and patterns

Existing WS Standards/

Infrastructure

Process Adaptation

Dynamic Process Configuration


Linking the different layers in a business process


Semantic Templates

• SAWSDL + Enhanced policy descriptions to model the data, functional and non-functional semantics at the various tiers– Business Process Tier: Capture process level

requirements– Implementation Tier: Capture partner level

requirements

• Non-functional semantics captured at template and operation levels.

• XML representation for interoperability.


Semantic Templates

• SAWSDL for data and functional semantics• Semantic Policy Descriptions for non-functional

semantics


Example of a semantic template in the supplychain domain


Dynamic Binding: Guiding principles

• Semantic templates to capture the requirements for each partner.

• Partners are selected during the run time of the process and the process is configured– Semantically Enhanced UDDI Registries for discovery

of partners.– Approaches to match enhanced policies (Sem-Pol) and

agreements (SWAPS)

• Execution environment supporting discovery, configuration and invocation.


Example of a process with semantic templates


Dynamic Configuration: Components

• Semantically enhanced Services Registry (SSR)– Domain aware services registry for publishing and

selecting services.– Extends UDDI data structures natively– Domain awareness allows for reasoning on annotations.– Support for WS-Policy and Enhanced WS-Policy for

service selection.– Mapping UDDI to SAWSDL


High Level Architecture of Middleware infrastructure

METEOR-S MIDDLEWARE

Workflow Engine(IBM BPWS4J)

Web Services

Discovery

Constraint Analysis

Configuration Module

Adaptation Module

MDP

Deployed Web Process

Configuration/Invocation Request Message

Configuration/Invocation Response Message

Eve

nt fr

om s

ervi

ce

Service invocation

Process and

Service Managers

Entities

Process Manager (PM): Responsible for global process configuration

Service Manager (SM): Responsible for interaction of process with service

Configuration Module (CM):Discovery and constraint analysis

Adaptation Module (AM): Process adaptation from exceptions/events


Towards Autonomy at the middleware level

• Self adapting, Self Optimizing, Self Healing and may be Self Buying (If you are selling these)

• What can go wrong, How do I know when things go wrong and what do I do?

• What can go wrong?– Identifying events

• How do I know when things go wrong?– Subscription management and notification management

• What do I do when things go wrong?– Adaptation modeling and Strategies


Algorithm for Event Identification

knowledge enabled information and services science semantics in services dr. amit p. sheth,...

Documents

services science semantics

knowledge enabled information

execution semantics

nonfunctional semantics

semantics ontology

service execution

wsdl slide

service descriptions