Kunal Verma1, Amit Sheth1,2 ,Francisco Curbera3

1
Service Oriented Architectures and Semantic Web
Processes

• Kunal Verma1, Amit Sheth1,2 ,Francisco Curbera3
• 1LSDIS Lab, University of Georgia
• 3Semagix, Inc (USA)
• 3IBM T.J. Watson Research Center (USA)

2

• Service Oriented Architectures and Web Services
• Semantic Web Services and Processes

3
Service Oriented Architectures and Web Services
Part
4
Overview

• IT for a new business model
• Service Oriented Architectures (SOAs).
• Web services as an XML based instantiation of
  SOA.
• Protocols.
• Metadata.
• Discovery.
• Composition.
• Summary.

5
A New Business Environment

• Business outsource every non-essential function.
• Concentrate on core function and values.
• Vertically integrated enterprises are being
  broken apart
• Replaced by heavily networked ones.
• Applications that used to be internal are now
  provided by outside parties.
• Corporate boundaries become fuzzier.
• Does todays IT models support the new business
  environment?
• IT is too centered on IT!
• When enterprises where islands this was sort of
  OK.
• Today it is vital to adapt the computing model to
  the business interaction model.

6
Enterprises as IT Islands
Value added networks and proprietary protocols
support most B2B interactions
Ad-hoc bridges support interorganizational
interactions.
Most application interactions take place inside
the enterprise.
Most applications belong to a single
administrative domain.
7
Fully Networked Enterprises
Web based interactions become pervasive, based on
standard protocols
The frequency of external interactions and their
reach inside the enterprise increases
dramatically.
Internal applications seamlessly reach out of the
enterprise.
Interacting applications naturally belong to
multiple administrative domains.
8
Fully Networked Business Interactions
The distinction between internal and external
applications and providers looses importance
Many potential providers can be found for each
required function.
9
IT for the New Enterprise Business Components

• Need to raise the level of IT abstractions.
• Concentrate on business function and
  requirements.
• Need to encapsulate business function to make it
  available to partners service components.
• Different level granularity coarse grained
  business services vs. fine grained objects.
• Services must be defined by explicit contracts to
  allow independent party access.
• Consequence is automatic binding.
• Core concern of business is to integrate business
  processes and functions.
• Business components are integrated creating
  service compositions.
• New value is created through integration/compositi
  on.
• New components are recursively created.

10
Service Oriented Middleware

• Service interactions
• Peer to peer by nature.
• Symmetric interaction model.
• Mixes synchronous and asynchronous protocols.
• Assigns public contracts to network accessible
  objects.
• Supports capability based service discovery.

Registry
QoSA/B? IfaceI etc
11
A Plan for Building a SOA

• Requirement 1 Interaction protocols must be
  standardized.
• Need to ensure the widest interoperability among
  unrelated institutions.
• Requirement 2 Make all contracts explicit.
• Explicit contracts define what may be changed in
  an application without breaking the interaction.
• It is hard or impossible to make all assumptions
  explicit, but the more the better.
• Requirement 2 Standardize contract language(s)
  and formats.
• Standard metadata is the basis of interoperable
  contract selection and execution.
• Requirement 3 Allow for points of variability
  in the contract.
• Dynamic adaptation on variability points.
• Increases the number of possible interactions
  supported.
• Requirement 4 Provide native composition models
  and runtimes.

12
Web Services As a SOA

• SOA and Web Services

13
Where Are We on Web Services?
Composition
BPEL4WS
WSDL, WS-Policy, UDDI, Inspection
Description
Quality of Service
Transactions
ReliableMessaging
Security
SOAP (Logical Messaging)
Interaction
Other protocols Other services
XML, Encoding
14
Protocols

• SOA and Web services

15
Protocols

• Provides a common set of universally supported
  interaction protocols.
• A basic messaging layer
• SOAP
• Easily extensible, allows QoS protocols to be
  defined on top.
• Some basic QoS protocols
• Basic requirements of business interactions.
• Provide guarantees
• Message Reliability, WS-ReliableMessaging
• Coordination and transactional interactions.
• Message integrity, confidentiality

16
SOAP (v1.1)

• A lightweight XML-based mechanism for exchanging
  structured information between peers in a
  distributed environment.
• A transport-independent messaging model.
• Transport bindings for HTTP
• An encoding model for a type system, and an RPC
  convention a link to legacy middleware.
• Built around a standard message format
• Envelope
• Headers
• Body
• Possibly attachments.

17
SOAP Messaging
18
SOAP over HTTP
POST /StockQuote HTTP/1.1 Host
www.stockquoteserver.com Content-Type text/xml
charset"utf-8" Content-Length nnnn SOAPAction
"Some-URI" ltSOAP-ENVEnvelope xmlnsSOAP-ENV
SOAP-ENVencodingStyle/gt ltSOAP-ENVHeadergt
lt/SOAP-ENVHeadergt ltSOAP-ENVBodygt
ltpoPlacePurchaseOrder xmlnspogt
ltOrderDategt02/06/01lt/OrderDategt
ltShip_Togt lt/po
PlacePurchaseOrder gt lt/SOAP-ENVBodygt lt/SOAP-EN
VEnvelopegt
19
SOAP Status

• SOAP 1.2/XML Protocol is now a W3C
  Recommendation.
• http//www.w3.org/TR/soap/
• SOAP 1.1 is still (and will be for a while) what
  is being deployed.
• http//www.w3.org/TR/2000/NOTE-SOAP-20000508/

20
WS-Security
ltwsseSecurity? ltwsseUsernameToken
Id"MyID"gt ltwsseUsernamegt Zoe
lt/wsseUsernamegt lt/wsseUsernameTokengt
ltdsSignaturegt ltdsSignatureMethod
Algorithm
"http//www.w3.org/..."/gt
ltdsSignatureValuegt DJbchm5gK...
lt/dsSignatureValuegt ltdsKeyInfogt
ltwsseSecurityTokenReferencegt
ltwsseReference
URI"MyID"/gt
lt/wsseSecurityTokenReferencegt
lt/dsKeyInfogt lt/dsSignaturegt lt/wsseSecuritygt

• SOAP header extensions for
• authentication,
• confidentiality,
• Integrity
• Built on top of W-Security
• Protocols for exchanging security tokens and
  establishing trust relationships built on top.
• Protocols for authorization and identity
  propagation / mapping in multi-party
  communication

21
Metadata

• SOA and Web services

22
Metadata

• WSDL Functional descriptions.
• WS-Policy QoS
• Points of variability dynamic infrastructure.

23
What is WSDL

• An extensible, platform independent XML language
  for describing services.
• Provides functional description of Web services
• IDL description
• Access protocol and deployment details
• All of the functional information needed to
  programmatically access a service, contained
  within a machine-readable format
• Does not include
• QoS
• Taxonomies
• Business information
• WSDL is a component definition language for Web
  service component

24
WSDL Description Structure
ltdefinitionsgt
lttypesgt ltmessage nameMsg1/gt ltportType
namePType1gt ltbinding nameBnd1
typePType1gt
Abstract/Business
ltservice namesvc1gt ltport bindingBnd1 gt
ltsoapaddress location.../gt
lt/portgt lt/servicegt
Deployment
lt/definitionsgt
25
WSDL Parts At a Glance
part
types
abstract interface portType
(abstract) operation
(concrete) message
(abstract) message
concrete implementation binding
(concrete) operation
(concrete) message
(concrete) message
made concrete by
service
concrete endpoint port
contains one or more
26
WSDL Status

• WSDL 1.1 was submitted to the W3C on February
  2001.
• http//www.w3.org/TR/WSDL
• WSDL 2.0 is now being defined by the WS
  Descriptions working group at W3C.
• Last draft (June 2002) available at
• http//www.w3.org/2002/ws/desc/

27
WS-PolicyFramework

• Complements functional description of services
  with QoS behaviors.
• General framework for declaratively asserting how
  a service may be accessed
• Requirements
• Constraints
• Capabilities
• WS-Policy provides a general framework in which
  arbitrary domain specific assertions are used.
• Security
• Transactions
• Reliable messaging

28
Policy Expressions
001 ltwspPolicy idgt 002
ltwspExactlyOnegt 003 ltwspAllgt 004
ltwsseSecurityTokengt 005
ltwsseTokenTypegtwsseKerberosv5TGTlt/wsseTokenType
gt 006 lt/wsseSecurityTokengt 007
ltwsseIntegritygt 008
ltwsseAlgorithm Type"wsseAlgSignature /gt 009
lt/wsseIntegritygt 010
lt/wspAllgt 011 ltwspAllgt 012
ltwsseSecurityTokengt 013
ltwsseTokenTypegtwsseX509v3lt/wsseTokenTypegt 014
lt/wsseSecurityTokengt 015
ltwsseIntegritygt 016
ltwsseAlgorithm Type"wsseAlgEncryption /gt 017
lt/wsseIntegritygt 018
lt/wspAllgt 019 lt/wspExactlyOnegt 020
lt/wspPolicygt
29
Policy Expressions

• Three generic policy operators allow combining
  assertions into groups, options
• ltAllgt
• ltExactlyOnegt
• ltOneOrMoregt
• Usage attribute allows modification of standard
  meaning of assertion
• UsageRejected prevents requesters from
  following certain behaviors (do not log
  messages!).
• Policies can be names so they can be referenced
  from other documents and reused.
• Id attribute assigns a URI to the policy.
• QName naming is also allowed.

30
WS-Policy and SOAP
ltwspPolicy idgt ltwsseSecurityTokengt
ltwsseTokenTypegt wsseX509v3
lt/wsseTokenTypegt lt/wsseSecurityTokengt lt/wsp
Policygt

• Policies define what QoS protocols are followed.
• Are reflected on what headers appear in the SOAP
  envelope.
• QoS policies attached to a service of service
  endpoint represent protocols.
• QoS protocols are supported by SOAP headers.

ltSOAP-ENVEnvelopegt ltSOAP-ENVHeadergt
ltwsseSecuritygt ltwsseBinarySecurityToken
Id"myToken"
ValueType"wsseX509v3" EncodingType
"wsseBase64Binarygt
MIIEZzCCA9Cg... lt/wsseBinarySecurityTokengt
lt/wsseSecuritygt lt/SOAP-ENVHeadergt ltSOAP
-ENVBodygt
31
Using WS-Policy

• Requester finds out QoS requirements stated by
  provider and configures itself accordingly
• Both development time and runtime usage.
• Many options may be available
• Requester searches for services that support its
  QoS requirements.
• Discovery time.
• Match-maker finds compatible services in peer to
  peer setting.
• Symmetric discovery scenario.
• Contracts may be formulated based on
  compatibility of published policies.
• Business implications of policy matching.

32
What is the Typical Usage Scenario

• Simple SOA model
• WSDL description or UDDI service entry identify
  all policies that are followed by a service.
• Service requesters check for services whose
  interface and policies indicate technical
  compatibility with their requirements.
• It is a static model
• Policies are used to represent the stack of
  technologies supported by the service.
• A match represents a service using a compatible
  policy stack.
• Typically results in implicit binding between
  application implementations.
• Loose coupling is limited to selecting among
  technically equivalent services, using
  non-functional aspects (price, ratings, etc.)
• This is a direct extension from todays
  development models.
• The stack is fixed at development/deployment
  time.
• SOA model essentially introduces the publishing
  of descriptions and runtime selection.

33
Dynamic Middleware Reconfiguration

• Effective dynamic binding requires run-time
  adaptation of middleware configuration
• J2EE focused on moving middleware configuration
  away from the code developer and into the
  deployment phase.
• SOC requires moving it further to follow runtime
  discovery of services
• Seamlessly adapt to policy settings of target,
  select among possible options, carry on basic a
  policy negotiation.

34
WS-Policy

• Status WS-Policy specifications published withy
  RF licensing terms at
• http//www-106.ibm.com/developerworks/webservices/
  library/ws-polfram/summary.html
• WS-PolicyFramework
• WS-PolicyAttachments
• To be submitted for standardization.

35
Discovery

• SOA and Web services

36
Discovery Infrastructure

• Registries
• Requesters search for providers in third party
  central directory.
• Provider policies are retrieved from registry.
• Requester interacts according to discovered
  policies.
• Will not deal with here.
• Metadata exchange
• Requesters and providers can exchange policies
  directly, no third party involved.

37
WS-Metadata Exchange

• Goal Allow providers to customize their policies
  to individual requesters and interactions.
• Requesters send
• Requesters policies can be explicitly
  communicated.
• Requesters execution context may be implicitly
  transmitted.
• Providers return set of policies to apply to
  interaction.
• Faults should be thrown if any party finds it
  cannot deal with the others policies.

Identity, context
1
Policy or fault
2
38
Composition

• SOA and Web services

39
Service Composition

• Service composition is the core sw. development
  task in SOA.
• Applications are created by combining the basic
  building blocks provided by other services.
• Service compositions may themselves become
  services, following a model of recursive service
  composition.
• Composition assumes an interaction model between
  components
• P2P conversational interactions.
• Interactions are naturally multi-party
  interactions.
• Many composition models are possible. We know
  about two
• Process oriented composition BPEL4WS
• Distributed composition WSFL Global models.

40
BPEL Concepts

• A BPEL process defines the structure of the
  interaction in terms of
• participant services (partners)
• Characterize partners
• Provide support partner conversation
• business logic.
• Data
• Control flow
• Error handling and recovery mechanism

41
Structure of a BPEL4WS Process

• ltprocess ...gt
• ltpartnersgt ... lt/partnersgt
• lt!-- Web services the process interacts with
  --gt
• ltcorrelationSetsgt ... lt/correlationSetsgt
• lt! Used to support asynchronous interactions
  --gt
• ltvariablegt ... lt/variablegt
• lt! Data used by the process --gt
• ltfaultHandlersgt ... lt/faultHandlersgt
• lt!Alternate execution path to deal with faulty
  conditions --gt
• ltcompensationHandlersgt ... lt/compensationHandle
  rsgt
• lt!Code to execute when undoing an action
  --gt
• (activities)
• lt! What the process actually does --gt
• lt/processgt

Partner information
Business logic
42
BPEL Partners

• Partners
• A composition defines a new service(s) which
  interacts with one or more partners.
• Partners are characterized by a pair of abstract
  WSDL interfaces
• How the composition uses and is used by the
  partner.
• Interactions between partners are thus
  bidirectional, conversational in nature.
• May combine synchronous and asynchronous
  interactions
• Stateful.
• How is state maintained?
• BPEL correlation mechanism uses business data to
  maintain the state of the interaction.
• Other middleware mechanism are possible as well.

43
BPEL4WS Partners
Multiple simultaneous conversations
Many partners
Characterized by WSDL interfaces
?
44
BPEL Basic Activities

• ltinvoke partner... portType...
  operation...
• inputContainer... outputContainer...
  /gt
• lt!-- process invokes an operation on a partner
  --gt
• ltreceive partner... portType...
  operation...
• container.../gt
• lt!-- process receives invocation from a
  partner --gt
• ltreply partner... portType...
  operation...
• container.../gt
• lt!-- process send reply message in partner
  invocation --gt
• ltassigngt lt! Data assignment betwee containers
  --gt
• ltcopygt
• ltfrom container.../gt ltto
  container.../gt
• lt/copygt
• lt/assigngt

45
BPEL Structured Activities

• ltsequencegt
• lt! execute activities sequentially--gt
• ltflowgt
• lt! execute activities in parallel--gt
• ltwhilegt
• lt! iterate execution of activities until
  condition
• is violated--gt
• ltpickgt
• lt! several event activities (receive message,
  timer event) scheduled for execution in parallel
  first one is selected and corresponding code
  executed. --gt
• ltlink ...gt
• lt! defines a control dependency between a
• source activity and a target --gt

46
Nesting Structured Activities. Example
ltsequencegt ltreceive .../gt ltflowgt
ltsequencegt ltinvoke .../gt ltwhile
... gt ltassigngt ... lt/assigngt
lt/whilegt lt/sequencegt ltsequencegt
ltreceive .../gt ltinvoke ... gt
lt/sequencegt lt/flowgt ltreplygt lt/sequencegt
Seq
Flow
Seq
Seq
While
47
Global Models

• BPEL processes capture multi-party interactions
  from a single party perspective.
• There isnt a well accepted format for capturing
  these interactions.
• Complex interactions are naturally multi-party.
• Single party view does not capture the global
  sequence of interactions
• Each party may not be involved in every relevant
  interaction.
• Where are global models?
• WSFL (a BPEL precursor) introduced global models.
• WS-Choreography WG in W3C has been working on
  this concept as well.

48
Global Models, an Example
49
Summary

• SOA and Web services

50
Web Services as an Instantiation of SOA

• SOA is more than publish/find/bind.
• Implies a completely business re-orientation of
  computing.
• SOA builds on
• Standard interaction protocols.
• A component model, as defined by service
  contracts.
• A conversational interaction model.
• A set of service composition model.
• Web services provide an XML based instantiation
  of SOA.

51
Semantic Web Services and Processes

Part
52
Semantic Web Processes Overview

• Introduction
• Semantics for Web Processes
• Data Semantics
• Functional Semantics
• QoS Semantics
• Execution Semantics
• Other Projects
• OWL-S
• WSMO
• Conclusions
• Demo

53
Our Focus (1)

• Supporting Web Processes on multi-enterprise and
  Web scale require addressing heterogeneity/integra
  tion, scalability, dynamic change and performance
  challenges
• Semantics is seen as the key enabler to address
  these challenges Semantic Web Processes build
  upon Web Services and Semantic Web technologies
• This part of tutorial is about adding semantics
  to Web Services, and exploiting them in Web
  Process Lifecycle (Specification, Discovery,
  Composition, Execution)
• Functional perspective takes form of process
  composition involving Web Service Discovery,
  handling semantic heterogeneity modeling data
  i/o, state (pre/post condition) and function
• Operational perspective takes form of the
  research on QoS Specification for Web Services
  and Processes modeling QoS and execution
  behavior

54
What are Web Processes (1)?
Web Processes

• Web Processes are next generation workflow
  technology to facilitate the interaction of
  organizations with markets, competitors,
  suppliers, customers etc. supporting
  enterprise-level and core business activities
• encompass the ideas of both intra and inter
  organizational workflow.
• created from the composition of Web services
• can use BPEL4WS to represent composition, but how
  to get there?

55
Example Business Process Supplier Selection and
Item Procurement Process
UDDI Registry
UDDI Query
Supplier 1
Locate Suppliers
Results
Item Details
Receive Quote
Send Quote Request
Quote Details
Check Inventory
Choose Supplier
Customer Terms
Negotiate Agreement
Negotiate Agreement
Supplier Terms
Order Details
Receive Order
Send Order
Order Confirmation
Supplier (s) Process
Customer Process
56
Evolving Business Models

• Traditional Business Model
• Fixed Business Process and Fixed Partners
• Statically change business process
• Emerging Business Model
• Change known partners based on business needs
• Dynamically change business process
• Future Business Model
• Dynamically select partners from exchanges or
  registries
• Dynamically create business processes from high
  level goals
• Automatically negotiate agreements

57
Challenges In Supporting Evolving Business Models

• Automatic Discovery
• Needs Automatically find right business partners
• Solution Create efficient discovery mechanisms
• Automatic Integration
• Needs How to understand others data
• Solution Agreement on data types (standard based
  / ontology based
• Optimization and Correctness
• Need Verify correctness of created process
• Solution Capture and reason on business and
  application constraints

Proposition Semantics is the most important
enabler to address these challenges.
58
Semantics, Ontologies, Semantic Web Processes

• When Web services and other descriptions that
  define a Web process are semantically described,
  we may call such process as Semantic Web
  Processes.
• An ontology provides semantic grounding. It
  includes a vocabulary of terms, and some
  specification of their meaning.
• The goal is to create an agreed-upon vocabulary
  and semantic structure for exchanging information
  about that domain.

Acknowledement Jorge Cardoso
59
Broad Scope of Semantic (Web) Technology
Lots of Useful Semantic Technology (interoperabil
ity, Integration)
Other dimensions how agreements are reached,
Cf Guarino, Gruber
60
Semantics for Business Processes
61
Semantics for Web Processes

• 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
• 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
• 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.
• QoS Semantics
• (Semi-) formally represent qualitative and
  quantitative measures of Web process
• Qualitative includes security, transactions
  (WS-Policy)
• Quantitative includes cost, time etc.
  (WS-Agreement)
• Business constraints and inter service
  dependencies (Domain and application ontologies)

62
Data and Functional Ontologyan example based on
Rosettanet
Functions
Data
63
QoS Ontology in METEOR-S
64
Semantics for Web Process Life-Cycle
Data / Information Semantics
65
Semantics for Web Process Life-Cycle
Development / Description / Annotation
Execution (Orchestration?)
WSDL, WSEL OWL-S WSDL-S METEOR-S (MWSAF)
BPWS4J, Commercial BPEL Execution Engines,
Intalio n3, HP eFlow
Data / Information Semantics
UDDI WSIL, OWL-S METEOR-S (MWSDI)
BPEL, BPML, WSCI, WSCL, OWL-S, METEOR-S (MWSCF)
Publication / Discovery
Composition (Choreography?)
66
Semantics for Web Process Life-Cycle
Development / Description / Annotation
Execution (Orchestration?)
WSDL, WSEL OWL-S WSDL-S METEOR-S (MWSAF)
BPWS4J, Commercial BPEL Execution Engines,
Intalio n3, HP eFlow
Functional Semantics
UDDI WSIL, OWL-S METEOR-S (MWSDI)
BPEL, BPML, WSCI, WSCL, OWL-S, METEOR-S (MWSCF)
Publication / Discovery
Composition (Choreography?)
67
Semantics for Web Process Life-Cycle
Development / Description / Annotation
Execution (Orchestration?)
WSDL, WSEL OWL-S WSDL-S METEOR-S (MWSAF)
BPWS4J, Commercial BPEL Execution Engines,
Intalio n3, HP eFlow
QoS Semantics
UDDI WSIL, OWL-S METEOR-S (MWSDI)
BPEL, BPML, WSCI, WSCL, OWL-S, METEOR-S (MWSCF)
Publication / Discovery
Composition (Choreography?)
68
Semantics for Web Process Life-Cycle
Development / Description / Annotation
Execution (Orchestration?)
WSDL, WSEL OWL-S WSDL-S METEOR-S (MWSAF)
BPWS4J, Commercial BPEL Execution Engines,
Intalio n3, HP eFlow
Execution Semantics
UDDI WSIL, OWL-S METEOR-S (MWSDI)
BPEL, BPML, WSCI, WSCL, OWL-S, METEOR-S (MWSCF)
Publication / Discovery
Composition (Choreography?)
69
Semantics for Web Process Life-Cycle
Development / Description / Annotation
Execution (Orchestration?)
WSDL, WSEL OWL-S WSDL-S METEOR-S (MWSAF)
BPWS4J, Commercial BPEL Execution Engines,
Intalio n3, HP eFlow
Semantics Required for Web Processes
UDDI WSIL, OWL-S METEOR-S (MWSDI)
BPEL, BPML, WSCI, WSCL, OWL-S, METEOR-S (MWSCF)
Publication / Discovery
Composition (Choreography?)
70
DATA SEMANTICS
71
Data Semantics
UDDI Registry
UDDI Query
Locate Suppliers
Results
Item Details
Receive Quote
Send Quote Request
Quote Details
Check Inventory
Choose Supplier

• How does the supplier recognize Item Details
• Pre-defined agreement on all data fields
• Use a standard like Rosetta Net/ebXML
• Annotate data fields with an ontology

Negotiate Agreement
Negotiate Agreement
Receive Order
Send Order
Supplier Process
Customer Process
72
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

73
Proposed Standard WSDL-S
74
WSDL-S Metamodel
75
WSDL-S
lt?xml version"1.0" encoding"UTF-8"?gt ltdefinition
s name "BatterySupplier" targetNamespace
"http//lsdis.cs.uga.edu/meteor/BatterySupplier.ws
dl20" xmlns "http//www.w3.org/2004/03/wsdl" x
mlnstns "http//lsdis.cs.uga.edu/BatterySupplie
r.wsdl20" xmlnsrosetta " http//lsdis.cs.uga.e
du/projects/meteor-s/wsdl-s/pips.owl
" xmlnsmephttp//www.w3. rosettaPurchaseOrderSt
atusResponse org/TR/wsdl20-patternsgt
ltinterface name "BatterySupplierInterface"
description "Computer PowerSupply Battery Buy
Quote Order Status "
domain"naicsComputer and Electronic
Product Manufacturing" gt ltoperation
name "getQuote" pattern "mepin-out" action
"rosettaRequestQuote" gt ltinput
messageLabel qRequest element
"rosettaQuoteRequest" /gt
ltoutput messageLabel quote element
"rosettaQuoteConfirmation" /gt
lt/operationgt ltoperation name
"placeOrder" pattern "mepin-out" action
"rosettaRequestPurchaseOrder" gt ltinput
messageLabel order element
"rosettaPurchaseOrderRequest" /gt
ltoutput messageLabel orderConfirmation
element "rosettaPurchaseOrderConfirmation"
/gt ltexception element "rosettaDiscountinuedI
temException" /gt ltpre condition
" order.PurchaseOrder.PurchaseOrderLineItem.Requ
estedQuantity gt 7" /gt lt/operationgt
ltoperation name "checkStatus"
pattern"mepin-out" action "rosettaQueryOrder
Status" gt ltinput messageLabel statusQuery
element "rosettaPurchaseOrderStatusQuery"
/gt ltoutput messageLabel status element
"rosettaPurchaseOrderStatusResponse" /gt
ltexception element "rosettaOrderNumberInvalidE
xception" /gt lt/operationgt
lt/interfacegt lt/definitionsgt
Function from Rosetta Net Ontology
Data from Rosetta Net Ontology
76
MWSAF- METEOR-S Web Service Annotation Framework
ltxsdcomplexType nameDate"gt ltxsdsequencegt  
ltxsdelement nameyear" type"xsdinteger" /gt  
ltxsdelement namemonth" type"xsdinteger" /gt
  ltxsdelement nameday" type"xsdbyte" /gt
lt/xsdsequencegt lt/xsdcomplexTypegt
WSDL
Ontologies
Data Semantics
Time - Ontology
Temporal-Entity
XML Schema Data type hierarchy
Web Service
Time Interval
Time Domain
Time-Point
absolute_time
Interfaces
Time
Date
hour, minute, second
year, month, day
Outputs
Inputs
Event
Date
Calendar-Date
Name
dayOftheWeek, monthOftheYear
Duration
Year
Scientific-Event
millisecond
Local ontology
City
Coordinates
x, y
Area
Get Conference Information
name
QoS Semantics
City
Forrest
QoS Ontology
Functional Semantics
Quality
WSDL
Information Function
Min
ltportType nameConferenceInformation"gt ltoperation
name"getInformation"gt   ltinput
message"tnsData" /gt   ltoutput
message"tnsConferenceInformation" /gt
lt/operationgt
Conference Information Functions
Get Information
Get Date
77
FUNCTIONAL SEMANTICS
78
Functional Semantics
UDDI Registry
UDDI Query
Locate Suppliers
Results
Item Details
Receive Quote
Send Quote Request
Quote Details
Check Inventory
Choose Supplier

• How to locate appropriate supplier
• Keyword based search in UDDI
• PortType based search in UDDI
• Semantic Discovery

Negotiate Agreement
Negotiate Agreement
Receive Order
Send Order
Supplier Process
Customer Process
79
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 be used to provide ranked results based on
  similarity users template

80
Semantic Discovery Overview

• Annotation and Publication
• WSDL file is annotated using ontologies and the
  annotations are captured in UDDI
• Discovery
• Requirements are captured as templates that are
  constructed using ontologies and semantic
  matching is done against UDDI entries
• Functionality of the template, its inputs,
  outputs, preconditions and effects are
  represented using ontologies
• Use of ontologies
• brings service provider and service requestor to
  a common conceptual space
• helps in semantic matching of requirements and
  specifications

81
Discovery in Semantic Web Using Semantics
Web Service Discovery

• Functionality What capabilities the requestor
  expects from the service (Functional
  semantics)
• Inputs What the requestor can give to the to the
  Web service (Data semantics)
• Outputs What the requestor expects as outputs
  from the service (Data semantics)
• QoS Quality of Service the distributor expects
  from the service (QoS semantics)

(Functional semantics)(Data semantics) (QoS
semantics) (Syntactic description)

• Description Natural language description of the
  service functionality (Syntactic description)

82
Semantic Publication and Template Based Discovery
For simplicity of depicting, the ontology is
shown with classes for both operation and data
Adding Semantics to Web Services Standards

83
DiscoveryThe Match Function

• The Web service discovery and integration process
  is carried out by a key operation
• The match function
• The matching step is dedicated to finding
  correspondences between a service template (ST,
  i.e., a query) and a service advertisement (SO).

84
Syntactic, QoS, and Semantic (Functional Data)
Similarity
Web Service Discovery
Syntactic Similarity
QoS Similarity
Functional Data Similarity
85
The Match FunctionSemantic Similarity

• Purely syntactical methods that treat terms in
  isolation from their contexts.
• It is insufficient since they deal with syntactic
  but not with semantic correspondences
• Users may express the same concept in different
  ways.
• Therefore, we rely on semantic information to
  evaluate the similarity of concepts that define
  ST and SA interfaces.
• This evaluation will be used to calculate their
  degree of integration.

86
The Match FunctionSemantic Similarity

• When comparing service templates with service
  advertisements, the following cases should be
  considered to be exact matches
• The input and output concepts of service template
  and advertisement are the same (ST(I) SA(I)
  and ST(O) SA(O) )
• The concept SA(I) subsumes concept ST(I). That
  is, requestor provides more information than the
  service needs SA(I) gt ST(I)
• The concept ST(O) subsumes concept SA(O). That
  is, the service provides more information than
  the requestor needs ST(O) gt SA(O)
• Otherwise, number of similar properties are used
  as a measure of similarity

87
The Match Function
SA2
ST
Event
SA1
Date
Scientific-Event
Date
Event
Date
ServiceAdvertisement
Service Advertisement
Service Template
Acknowledement Jorge Cardoso
88
The Match Function(ST(I) SA(I) and ST(O)
SA(I))
ST
SA1
Date
Event
Date
Event
Service Template
Service Advertisement
Temporal
-
Entity
Temporal
-
Entity
2
Time
Time
Time
-
Point
Time
-
Point
Domain
Domain

absolute_time


absolute_time

1
1
Time
Time
Date
Date
year, month, day
year, month, day
hour, minute, second
hour, minute, second
4
3
2
Event
Event
Calendar
-
Date
Calendar
-
Date
dayOftheWeek
,
monthOftheYear


dayOftheWeek
,
monthOftheYear

Scientific
-
Event
Scientific
-
Event
millisecond
millisecond
Acknowledement Jorge Cardoso
89
The Match Function(SA(I) gt ST(I) and ST(O)
SA(I))
ST
SA1
Date
Event
Calendar-Date
Event
Service Template
Service Advertisement
Temporal
-
Entity
Temporal
-
Entity
2
Time
Time
Time
-
Point
Time
-
Point
Domain
Domain

absolute_time


absolute_time

1
1
Time
Time
Date
Date
year, month, day
year, month, day
hour, minute, second
hour, minute, second
4
3
2
Event
Calendar
-
Date
Calendar
-
Date
Event
dayOftheWeek
,
monthOftheYear


dayOftheWeek
,
monthOftheYear

Scientific
-
Event
Scientific
-
Event
millisecond
millisecond
Acknowledement Jorge Cardoso
90
The Match Function(ST(I) SA(I) and ST(O) gt
SA(O))
ST
SA1
Date
Scientific-Event
Event
Date
Service Template
Service Advertisement
Temporal
-
Entity
Temporal
-
Entity
2
Time
Time
Time
-
Point
Time
-
Point
Domain
Domain

absolute_time


absolute_time

1
1
Time
Time
Date
Date
year, month, day
year, month, day
hour, minute, second
hour, minute, second
4
3
2
Event
Event
Calendar
-
Date
Calendar
-
Date
dayOftheWeek
,
monthOftheYear


dayOftheWeek
,
monthOftheYear

Scientific
-
Event
Scientific
-
Event
millisecond
millisecond
Acknowledement Jorge Cardoso
91
METEOR-S Web Service Discovery Infrastructure
(MWSDI)

• MWSDI deals with adding semantics to UDDI
  registries
• Provides transparent access to UDDI registries
  based on their domain or federation
• Implementation of UDDI Best Practices and
  Semantic Discovery

1 http//lsdis.cs.uga.edu/Projects/METEOR-S
92
Extended Registries Ontologies (XTRO)

• Provides a multi-faceted view of all registries
  in MWSDI
• Federations
• Domains
• Registries

93
Types of Queries Supported

• What is the access URL, available data model or
  type of the registry R?
• Does the registry R support the ontology O?
• Which are the registries available under the
  business domain B?
• Is the registry X a member of the registry
  federation Y?
• Which registries pertain to the domains that
  support the ontologies O1 and O2?
• Get all the registry federations that belong to
  the domain D?
• Find all the registries that are categorized
  under the node N in the taxonomy (or ontology) C?

94
QoS SEMANTICS

• Business and Application constraints

95
QoS Semantics
UDDI Registry
UDDI Query
Locate Suppliers
Results
Item Details
Receive Quote
Send Quote Request
Quote Details
Check Inventory
Choose Supplier

• QoS Semantics
• Does the supplier support customers business
  constraints
• Interaction should adhere to the entities
  policies

Negotiate Agreement
Negotiate Agreement
Receive Order
Send Order
Supplier Process
Customer Process
96
QoS Semantics

• Does the supplier support customers 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 suppliers parts do not work with
  other suppliers parts

97
METEOR-S Web Service Composition Framework
DesignTime
Abstract Process
Abstract Process Designer
Executable Process
Binder
Process Repository
BPWS4J Execution Engine
Service Template(s) (PUBLISH)
Process Instance Initiation Time
Process Annotation Tool
Optimized Service Set
Constraint Analyzer
Discovery Engine
Enhanced UDDI
98
Composition in METEOR-S

• User defines High level goals
• Abstract BPEL process (control flow without
  actual service bindings )
• Process constraints on QoS parameters
• Generic parameters like time, cost, reliability
• Domain specific parameters like supplyTime
• Domain constraints captured in ontologies
• E.g preferred suppliers, technology constraints

99
Sample Abstract BPEL Process

• ltprocess name"orderProcess"
• targetNamespace"http//tempuri.org/"
• xmlns"http//schemas.xmlsoap.org/ws/2003/03/bus
  iness-process/"
• xmlnstns"http//tempuri.org/"gt
• ltpartnerLinksgt
• ltpartnerLink name"User" xmlnsns1"tns"
  partnerLinkType"ns1UserSLT"/gt
• ltpartnerLink name"orderPartner" xmlnsns2"?"
  partnerLinkType"ns2?"/gt
• ltpartnerLink name"orderPartner2" xmlnsns8"?"
  partnerLinkType"ns8?"/gt
• lt/partnerLinksgt
• ltflow name"start"gt
• ltinvoke name"orderPArt" partnerLink"orderPartner
  " xmlnsns7"?" portType"ns7?" operation"?"
  inputVariable"orderInput" outputVariable"orderOu
  tput"gt
• lt/invokegt
• ltinvoke name"orderPArt2" partnerLink"orderPartne
  r2" xmlnsns9"?" portType"ns9?" operation"?"
  inputVariable"orderInput" outputVariable"orderOu
  tput"gt
• lt/invokegt

DEFINITIONS
Unknown partners
FLOW
100
Constraint Analyzer/Optimizer

• Constraints can be specified on each activity or
  on the process as a whole.
• An objective function can also be specified e.g.
  minimize cost and supply-time etc
• The Web service publishers provide constraints on
  the web services.
• The constraint optimizer makes sure that the
  discovered services satisfy the client
  constraints and then optimizes the service sets
  according to the objective function.

101
Constraint Representation Domain Constraints
Fact OWL expression
Supplier1 is an instance of network adaptor supplier Supplier1 supplies Type1 Supplier1 is a preferred supplier. ltNetworkAdaptorSupplier rdfID"Supplier1"gt ltsupplies rdfresource"Type1"/gt ltsupplierStatusgtpreferred lt/supplierStatusgt lt/NetworkAdaptorSuppliergt
Type1 is an instance of NetworkAdaptor Type1 works with Type1Battery ltNetworkAdaptor rdfID"Type1"gt ltworksWithgt ltBattery rdfID"Type1Battery"gt lt/worksWithgtlt/ NetworkAdaptor gt
102
Constraint Representation Process Constraints
Feature Goal Value Unit Aggregation
Cost Optimize Dollars S (minimize total process cost)
supplytime Satisfy lt 7 Days MAX (Max. supply time below Value)
partnerStatus Optimize MIN (Select best partner level lower value for preferred partner)
103
Integer Linear Programming

• Constraints are converted into linear
  equalities/linear inequalities over a set of
  discovered services.
• We have used LINDO API which helps in solving ILP
  problems.
• e.g. if three services match the service template
  with a constraint that costlt500 and minimum
• A B C 2 (choose 2 services)
• CAA CBB CCC lt 500 (total cost constraint)
• And minimize (CAA CBB CCC) as objective
  function (where A, B and C are
  binary)

104
Working of Constraint Analyzer
DiscoveryEngine
Abstract ProcessSpecifications
Service Template 1
Service Template 2
Service templates and service constraints
Process constraints Supply-timelt7 Costlt400 Min
(Cost, Supply-time)
Supply-time lt 3 Cost lt300 Battery
Supply-time lt 4 Cost lt200 Network Adaptor
ST3 C180
ST4 C200
Domain constraints in ontologies
ST1 C300
ST3 C200
Objective Functionand Process constraintsMin
(supply-time cost)
Optimizer (ILP)
Domain Reasoner (DL)
ST3 C250
ST2 C100
Most optimal set cannot be chosen because of
inter service dependenciesNetwork Adaptor from
supplier 1 does not work battery from supplier 2
ST3 C250
ST2 C100
ST2 C100
ST3 C250
ST4 C200
ST3 C180
ST3 C180
ST4 C200
Ranked Set
Ranked Set
105
EXECUTION SEMANTICS
106
Execution Semantics
UDDI Registry
UDDI Query
Locate Suppliers
Results
Item Details
Receive Quote
Send Quote Request
Quote Details
Check Inventory
Choose Supplier

• Execution Semantics
• Do the processes violate each others
  conversation protocols

Negotiate Agreement
Negotiate Agreement
Receive Order
Send Order
Supplier Process
Customer Process
107
Using Colored Petri nets
108
DEMOS

• Demo of Semantic Web Service Annotation using
  METEOR-S Eclipse Plugin
• Demo of Web Process Optimization using METEOR-S
  Web service composition tool

109
Related Projects

• OWL-S, WSMO

110
OWL-S

• OWL-S (formerly DAML-S) provides support for the
  following
• Service Advertisements (OWL-S Upper ontology)
• Functional Aspects (IOPEs)
• Non functional Aspects ( Geog Rad., Quality
  Rating etc.)
• Interaction Protocol using process model
• Discovery of services (OWL-S Matchmaker)
• Subsumption based discovery
• Composition (OWL-S process model)
• Support for hierarchical planning (e.g. SHOP2)
• Invocation (OWL-S VM )

111
OWL-S

• OWL-S
• Formerly OWL-S
• Set of markup language constructs for describing
  the properties and capabilities of their Web
  services in unambiguous, computer-intepretable
  form

112
OWL-SIntroduction
OWL-S

• OWL-S
• DAML (DARPA Agent Markup Language)
• OWL-S Upper ontology of web services
• OWL-S provides support for the following
  elements
• Process description.
• Advertisement and discovery of services.
• Selection, composition interoperation.
• Invocation.
• Execution and monitoring.

OWL-S project home page
113
OWL-SOntologies

• OWL-S defines ontologies for the construction of
  service models
• Service Profiles
• Process Models
• Service Grounding

114
OWL-SService Profile

• The Service Profile provides details about a
  service.

Inputs. Inputs that should be provided to invoke
the service.
Outputs. Outputs expected after the interaction
with the service.
Receipt
Client
Itinerary
Local
Tourism
Web Service
Preconditions. Set of conditions that should hold
prior to the service being invoked.
Effects. Set of statements that should hold true
if the service is invoked successfully.
115
Service Profile An example of Inputs and Outputs

• ...
• lt!ENTITY temporal "http//ovid.cs.uga.edu8080/scu
  be/daml/Temporal.daml"gt
• lt!ENTITY address "http//ovid.cs.uga.edu8080/scub
  e/daml/Address.daml"gt
• ...
• ltinputgt
• ltprofileParameterDescription rdfID"Addr"gt
• ltprofileparameterNamegt Addr lt/profileparameterN
  amegt
• ltprofilerestrictedTo rdfresource"addressAdd
  ress"/gt
• ltprofilerefersTo rdfresource"congocongoBuyR
  eceipt"/gt
• lt/profileParameterDescriptiongt
• lt/inputgt
• ...
• ltoutputgt
• ltprofileParameterDescription rdfID"When"gt
• ltprofileparameterNamegt When lt/profileparameterN
  amegt
• ltprofilerestrictedTo rdfresource"temporalDa
  te"/gt
• ltprofilerefersTo rdfresource"congocongoBuyR
  eceipt"/gt
• lt/profileParameterDescriptiongt
• lt output gt

Outputs
Inputs
When
Addr
...
,,,
...
116
Semantic Web Services (WSMO)

• WSMO (Web Services Modeling Ontology)
• Two parts
• WSML Semantic Web Service Language based on
  F-logic
• WSMX Semantic Web Service Architecture
• Based on WSMF proposed by Bussler and Fensel
• WSMO Supports
• Functional Aspects (IOPEs) used mediators
• Non Functional Aspects performance,
  reliability, security etc.
• Mediators (components cannot communicate without
  them)
• Petri nets for execution semantics

117
WSMO - Goals

• A goal specifies the objectives that a client may
  have when he consults a web service
• E.g. of goals
• Buy a book
• Buy a book from Amazon
• Buy a book written by X
• Mediators can combine or refine goals
• E.g. Buy a book from Amazon written by X

118
Semantic Web Services (WSMO)

• Two types of mediators
• Refiners define a new component as a refinement
  of an existing component
• ggMediators mediators that link two goals. This
  link represents the refinement of the source goal
  into the target goal.
• ooMediators mediators that import ontologies and
  resolve possible representation mismatches
  between ontologies

119
Semantic Web Services (WSMO)

• Two types of mediators
• Bridges support reuse by enabling two components
  to interact with each other
• wgMediators mediators that link web service to
  goals. They explicitly may state the difference
  (reduction) between the two components and map
  different vocabularies (through the use of
  ooMediators).
• wwMediators mediators linking two Web Services.

120
Semantic Web Services (WSMO)Example of using
mediators
121
Other Projects and Initiatives

• SWSI
• SWSA Semantic Web Services Architecture
• SWSL Semantic Web Services Language
• WonderWeb http//wonderweb.man.ac.uk/
• Development of a framework of techniques and
  methodologies that provide an engineering
  approach to the building and use of ontologies.
• Development of a set of foundational ontologies
  covering a wide range of application domains.
• Development of infrastructures and tool support
  that will be required by real world applications
  in the Semantic Web.

122
Conclusions
123
Conclusions

• SOA, Web processes, and Semantic Web processes
• Semantics can help address big challenges related
  to scalability, dynamic environments.
• But comprehensive approach to semantics will be
  needed
• Data/information, function/operation, execution,
  QoS
• Semantic (Web) principles and technology bring
  new tools and capabilities that we did not have
  in EAI, workflow management of the past
• SWP
• Semantics Data, Function, QoS, Execution
• Affects full Web Service/Process lifecycle
  Annotation, Publication, Discovery, Composition,
  Binding, Execution

More at http//lsdis.cs.uga.edu/proj/meteor/SWP.h
tm
124
Semantic Web Processes
Questions?
125
References Partial List

• WSMO www.wsmo.org
• OWL-S www.daml.org/services/owl-s/
• METEOR-S lsdis.cs.uga.edu/Project
• Aggarwal et al., 2004 Rohit Aggarwal, Kunal
  Verma, John A. Miller and William Milnor,
  "Constraint Driven Web Service Composition in
  METEOR-S," Proceedings of the 2004 IEEE
  International Conference on Services Computing
  (SCC 2004), Shanghai, China, September 2004 , pp.
  23-30
• Cardoso et al., 2004 Jorge Cardoso, Amit P.
  Sheth Semantic E-Workflow Composition. J.
  Intell. Inf. Syst. 21(3) 191-225 (2003)
• Sivashanmugam et al., 2003 Sivashanmugam, K.,
  Verma, K., Sheth, A., Miller, J., Adding
  Semantics to Web Services Standards, Proceedings
  of the 1st International Conference on Web
  Services (ICWS'03), Las Vegas, Nevada (June 2003)
  pp. 395-401
• Sivashanmugam et al., 2004 Kaarthik
  Sivashanmugam, Kunal Verma, Amit P. Sheth,
  Discovery of Web Services in a Federated Registry
  Environment, Proceedings of IEEE Second
  International Conference on Web Services, June,
  2004, pp. 270-278 
• Verma et al. 2004 Kaarthik Sivashanmugam, Kunal
  Verma, Amit P. Sheth, Discovery of Web Services
  in a Federated Registry Environment, Proceedings
  of IEEE Second International Conference on Web
  Services, June, 2004, pp. 270-278 
• Verma et al. 2004 Kunal Verma, Rama Akkiraju,
  Richard Goodwin, Prashant Doshi, Juhnyoung Lee,
  On Accommodating Inter Service Dependencies in
  Web Process Flow Composition, Proceedings of the
  AAAI Spring Symposium on Semantic Web Services,
  March, 2004, pp. 37-43

126
SOA andSemantic Web Processes
End
127
Service Oriented Architectures and Web Services
End
128
Back up slides
129
Matching Issues (WSDL and Ontologies)

• Expressiveness
• Different reasons behind their development
• XML Schema used in WSDL for providing basic
  structure to data exchanged by Web services
• Ontologies are developed to capture real world
  knowledge and domain theory
• Knowledge captured
• XML Schema has minimal containment relationship
• Language used to describe ontologies model real
  world entities as classes, their properties and
  provides named relationships between them
• Solution
• Use hueristics to create normalized
  representation
• We call it SchemaGraph

130
Normalization SchemaGraph

• What is SchemaGraph ?
• Normalized representation to capture XML Schema
  and DAML Ontology
• How to use SchemaGraph
• Conversion functions convert both XML Schema and
  Ontology to SchemaGraph representation
• XML schema used by WSDL ? W wc1, wc2, wc3, ,
  wcn where, wci is an element in XML schema and n
  is the number of elements
• Ontology ? O