knowledge enable information & services science kno.e.sis centerkno.e.sis wright state...

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Knowledge enable Information & Services Science

Kno.e.sis Center

Wright State University, Dayton, OH.

Role of semantics in Autonomic & Adaptive Web Services and Processes

Amit ShethLexisNexis Ohio Eminent Scholar

Amit ShethLexisNexis Ohio Eminent Scholar

Historical work - samples

1. "From Contemporary Workflow Process Automation to Adaptive and Dynamic Work Activity Coordination and Collaboration", Keynote Address at the Workshop on Workflows in Scientific and Engineering applications, Toulouse, France, September 1997.

2. Y. Han, A. Sheth, K. Bussler, "A Taxonomy of Adaptive Workflow Management," CSCW-98 Workshop Towards Adaptive Workflow Systems, November 14, 1998.

3. A. Sheth, W. Aalst, and I. Arpinar, “Processes Driving the Networked Economy,” IEEE Concurrency, 7 (3), July-September 1999, pp. 18-31.

Several projects in 1990s that dealt with adaptive and dynamic workflows (ADEPT, eFlow, METEOR, WAMO, etc.)

Talk focus

• Need a rich representational framework to capture requirements and capabilities to support adaptive and autonomic services and processes• SEMANTICS

• Earlier work on adaptive and dynamic workflows/business processes• What has changed?

SAWSDL became W3C Candidate Recommendation last week.

http://www.w3.org/2002/ws/sawsdl/

Asp

ect o

f Ag

reem

en

t

Gen. Purpose,Broad Based

Scope of Agreement

Task/ App

Domain Industry

CommonSense

Tech

nic

al

Peop

leO

rgan

izatio

n

A

greem

ent About

Data/Info.

Functional

Non Functional

Execution

Ontologies to Describe Service Semantics(ontologies are about agreements)

METEOR-S

Implementation Layer (Databases, OS, etc.)

Execution Layer (SOA Based IT Processes and Services)

Strategy Layer (Corporate Strategy and Goals)

Operational Layer (Modeling Business Process to provide business services)

Strategy Layer Requirement:

Only Provide customer support to gold customer

IT Layer Requirement:

If cost > $$$$, customer = gold

Autonomic Web Process*

• Self Healing

• Agile

• Self Optimizing

• Self Configuring

*it’s about the business, not just computing resourceshttp://lsdis.cs.uga.edu/library/publications/?t=Autonomic%20Web%20Processes

Semantics for Services Lifecycle

• Data/Information Semantics• What: (Semi-)Formal definition of data in input and output messages of a web service• Why: for discovery and interoperability• How: by annotating input/output data of web services using ontologies• Model References on Messages in SAWSDL

• Functional Semantics• (Semi-) Formally representing capabilities of web service• for discovery and composition of Web Services• by annotating operations of Web Services as well as provide preconditions and effects• Model References on Operations in SAWSDL

• Non Functional Semantics (WS-*)• (Semi-) formally represent qualitative and quantitative measures of Web process• Non- Quantitative includes security, transactions • Quantitative includes cost, time etc. • Business constraints and inter service dependencies (Domain and application ontologies)• Via attaching Semantically Enhanced Policies and Agreements to SAWSDL interfaces.

• Execution Semantics• (Semi-) Formally representing the execution or flow of a services in a process or operations

in a service• for analysis (verification), validation (simulation) and execution (exception handling) of the

process models• using State Machines, Petri nets, activity diagrams etc.

Adding Semantics to Web Service Standards, ICWS 2003

SAWSDL + SemPol= Semantic Templates

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

functional semantics

Semantic Template in action

Data Semantics

Functional Semantics

Non-Functional Semantics


Development/ Description/ Annotation WSDL, WSDL-S,

SAWSDL, WSMO, OWL-S

METEOR-S (MWSAF)

Publication/ Discovery

(Semantic) UDDI METEOR-S

(MWSDI) Composition,

Configuration and

Negotiation

WS-BPEL, WS-Agreement, WS-

Policy

Execution, Adaptation and

MediationOracle BPM,

activeBPEL, WSMX

Four types of semantics in services lifecycle

http://www.ics.forth.gr/isl/essw2003/talks/seth_essw_semanticwebprocess.htm

DataSemantics

Development/ Description/ Annotation


MediationBPWS4J,

activeBPEL.

WSMX

METEOR-S

Composition, Configuration

and Negotiation

BPEL, WS-Agreement, WS-

Policy METEOR-S (MWSCF)



(MWSDI)

WSDL, WSDL-S, SAWSDL, WSMO,

OWL-SMETEOR-S (MWSAF)


FunctionalSemantics



MediationBPWS4J,

activeBPEL,

WSMX

METEOR-S


and Negotiation





(MWSDI)




Non Functional Semantics



MediationBPWS4J,

activeBPEL,

WSMX

METEOR-S


and Negotiation





(MWSDI)




ExecutionSemantics



MediationBPWS4J,

activeBPEL,

WSMX

METEOR-S


and Negotiation





(MWSDI)




ExecutionSemantics


FunctionalSemantics

DataSemantics



MediationBPWS4J,

activeBPEL,

WSMX

METEOR-S


and Negotiation





(MWSDI)




Approaches to modeling Data Semantics

• Pre-defined agreement on all data fields• Limited flexibility, hard to integrate new suppliers in process

• Use a standard like Rosetta Net/ebXML• Greater flexibility, but limited to suppliers following standard• Standard may not be expressive enough for everyone's needs

• Annotate data fields with domain ontologies• Most flexible, semi-automatic transformation based on ontology

mapping• Ontology can be based on domain standard, while providing

more flexibility and extensibility• Data mediation can be realized using XSLT transformation,

addressing data heterogeneities.

Capturing Data semantics using SAWSDL

• Annotation on input and output messages in WSDL documents

• Leaf level annotation for complex types• Schema level annotation• Example of message level annotation:

Representing mappings for data mediation

<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

WSDL complex type element

.... <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: Add Meena et al, ICWS 2006 as refernece.

Functional Semantics

• Keyword based search in UDDI• Needs human involvement

• Low precision and high recall

• Port Type based search in UDDI• Requires service providers to agree on port types

• Less flexible, requires total agreement on method names and data type names

• Template Based Semantic Discovery• Requires ontological commitment of data types and operations

• Can search on any or many aspects of description+interface

• Can have complex similarity measures and be used to provide ranked results based on similarity

Semantic Discovery

• Semantic based publication and discovery

• Unlike interface and operation based publication and discovery, semantics are modeled into UDDI data structures

• SAWSDL descriptions can be published and template based discovery is supported.


• Business and Application constraints


• Does the supplier support customer’s business constraints

• e.g. cost, supply time etc.

• Interaction should adhere to the entities’ policies

• e.g security, transactions

• In case of more suppliers, domain constraints should be satisfied

• e.g. a certain supplier’s parts do not work with other supplier’s parts

• Non functional semantics in a semantic template:

• Template level policy: Akin to service level policy.

• Operation level policy: Policy for a specific operation in the template.


• Used in lifecycle• Agreement Matching

• Matching syntactically heterogeneous by semantically homogeneous agreements

• Dynamic Process Configuration• Configuring process based on process constraint

We will demonstrate how ontology-driven semantic approach supports these capabilities.

SWAPS: Use of Semantics in Agreement Matching

An agreement is a collection of alternatives.A={Alt1, Alt2, …, AltN}

An alternative is a collection of guarantees.Alt={G1, G2, ...GN}

A guarantee is defined as a collection-G={Scope, Obligated, SLO, Qualifying Condition, Business Value}

There is a potential match between provider and consumer alternatives if:

For all requirement of one alternative, there is a capability in other alternative, which has the same scope and the same obligation and the SLO of the capability satisfies the request.

“requirement(Alt, G)” returns true if G is a requirement of Alt“capability(Alt, G)” returns true if G is an assurance of Alt“scope(G)” returns the scope of G“obligation(G)” returns the obligated party of G“satisfies(Gj, Gi)” returns true if the SLO of Gj is equivalent toor stronger than the SLO of Gi

An alternative Alt1 is a suitable match for Alt2 if: ("Gi) such that Gi Alt1 requirement(Alt1, Gi) ($Gj) such that Gj Alt2 capability(Alt2, Gj) scope(Gi) = scope(Gj) obligation(Gi) = obligation(Gj) satisfies(Gj, Gi)

WS-Agreement Definition and Ontology

GuaranteeTerm

ScopeServiceLevelObjectivev

OWL ontology

Predicate

Parameter

hasScope

hasObjective

Unit

Value

hasCondition

Qualifying Condition

Predicate

ParameterUnit

Value

BusinessValue

Penalty

Reward

hasReward

hasPenalty

hasGuaranteeTerm

Importance

hasImportance

hasBusinessValue

Assessment IntervalValueExpression

ValueUnit

TimeInterval Count

Assessment Interval

ValueExpression

ValueUnit

TimeInterval

Count

An agreement consists of a collection of Guarantee terms

A guarantee term has a scope – e.g. operation of service

A guarantee term may have collection of service level objectives

e.g. responseTime < 2 seconds

A guarantee term may have a qualifying condition for SLO’s to hold.

e.g. numRequests < 100

There might be business values associated with each guarantee terms. Business values include importance, confidence, penalty, and reward.

e.g. Penalty 5 USD

Agreement represented as an instance of ontology

http://www2006.org/programme/item.php?id=5022

Using Semantic Agreements with SAWSDL

Time

Domain Independent

QoS

WS-Agreement Ontology

Guarantee

SLOObligated

BVScope

Predicate

Greater

Less

Quality

Moisture

Weight

Split

Price

FarmerAddr

Crop

Agriculture Ontology

GetMoisture

GetWeight

GetPrice

GetSplits

Merchant Service WSDL-S

WS-Agreement

agri:moisture less 12%

obligated: less 12%agri:splits less 20%

agri:weight greater 54 lbs

agri:price equals 10 USDInput: Address

Merchant WS-Agreement

Domain Dependent

Adding Semantics to Agreements:

Improves Monitoring and Negotiation

Improves the accuracy of matching

Adding Semantics to Web Services:

Enables more accurate discovery andcomposition.

SWAPS Ontologies

WS-Agreement: individual agreements are instances of the WS-Agreement ontology

Temporal Concepts: time.owl (OWL version of DAML time http://www.isi.edu/~pan/damltime/time.owl)Concepts: seconds, dayOfWeek, ends

Quality of Service: Max Maximilien’s QoS ontology (IBM) -> Ont-QosConcepts: responseTime, failurePerDay

Domain Ontology: an ontology used to represent the domain

http://lsdis.cs.uga.edu/projects/meteor-s/swaps/

Dynamic Process Configuration

Find optimal partners for the process based on process constraints – cost, supply time, etc.

Conceptual Approach

1. Create framework to capture represent domain knowledge

2. Represent constraints on the domain knowledge

3. Ability to reason on the constraints and configure the process

Dynamic Process Configuration

Research Challenges• Capturing functional and non-functional

requirements of the Web process (Abstract process specification)

• Discovering service partners based on functional requirements (Semantic Web service discovery)

• Choosing optimal partners that satisfy non-functional requirements (Constraint Analysis)

K. Verma, R. Akkiraju, R. Goodwin, P. Doshi, J. Lee, On Accommodating Inter Service Dependencies in Web Process Flow, AAAI Spring Symposium on Semantic Web Services, 2004R. Aggarwal, K. Verma, J. A. Miller, Constraint Driven Composition in METEOR-S, SCC 2004.K. Verma, K.Gomadam, J. Miller and A. Sheth, Configuration and Execution of Dynamic Web Processes, LSDIS Lab Technical Report, 2005.

Autonomic Web Process Vision

K. Verma, A. Sheth. Autonomic Web Processes. In Proceedings of the Third International Conference on Service-oriented Computing (ICSOC), Vision Paper (invited), LNCS 3826, Springer Verlag, 2005, pp. 1-11.

Extending service skeleton to handle business level exceptions

Technical Details to Follow

• Karthik Gomadam• Creating infrastructure for dynamic configuration• Identifying events from semantic templates

• Prashant Doshi• MDP based approach to adaptation in Web

processes.

Conclusions

• Four types of semantics• Data, Functional, Non-Functional and Execution Semantics. • Role played in the lifecycle of Web process

• Modeling data, functional and non-functional semantics using semantic templates

• Capturing the four types of semantics using SAWSDL• Vision of Autonomic Web process • Modeling service execution using service skeletons.

More at http://knoesis.org

knowledge enable information & services science kno.e.sis centerkno.e.sis wright state...

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