1 introduction to web services quality model and collaboration issues for eerp 2007.12.12 sojung kim...
TRANSCRIPT
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Introduction to Web Services Quality ModelAnd
Collaboration Issues for EERP
2007.12.12
Sojung KimWSQM TC
National Information society Agency
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A table of contents
Critical Issue in SOA
WSQM
WS-Quality Factor
Next Step
EERP & WSQM
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Service Quality Issues have gained attention in SOA paradigm– SOA Governance : stakeholders’ role and responsibility
– Different Service Life Cycle and a variety of stakeholders
• Service Acquirer/Developer/Consumer, Quality Information Provider, Quality/Assuror/Authenticator/Manager
– Role of service registry and responsibility for guaranteed service
What EERP wants– To build freestanding value networks in SOA
– Deal with traditional but critical issues – Quality of Services effectively
WSQM provides– From well known system information quality to business value quality
Critical Issues in SOA
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Overview– To prepares a quality model in the context of
contracting for Web services between associates conceptually, in order to secure Web services at a specific level of service quality
Scope– To specify an overall model of quality of Web services
in WSQM TC, It will include specified quality factors, associate roles, and activities
WSQM TC
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WSQM TC : Background & Needs
Requirements for definition of Service Quality according to Web Service
proliferation
Motivation for activating quality activity of Web service associates
To help to make consensus between Web Service associates
ex) negotiation/contracts
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WSQM
A model for configuring Web service quality or differentiating service level It consists of 3 components: Quality Factor, Quality Associate, and Quality Activity.
Quality Factor: fundamental components that recognize Web services quality as the target for control. Quality Associates: roles or tasks of the organizations or persons related with Web services. Quality Activity: various actions performed by associates
Quality AssociatesQuality Associates Quality FactorsQuality Factors
Quality ActivitiesQuality Activities
Perform Use
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Service stakeholder
ServiceDeveloper
Development Quality Contract
ServiceProvider
ServiceConsumer
Management QualityContract
ServiceServiceDevelopmentDevelopment
ServiceServiceOperation &Operation &ManagementManagement
Quality Manager
Service Broker
Service userService user
Example of Quality Activity • Development Quality Contract:
between Stakeholder and DeveloperDelivery time, Interoperability, Usability, Security
• Management Quality Contract: between Provider and Quality ManagerManageability, Composability
Service QualityContract
WSQM : Quality Activities
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WS-Quality Model v1.0
WS-Quality Factor v1.0WS-Quality
Description Language v1.0
WS-Quality Use Case v1.0WS-Quality
Test Guideline v1.0
WS-Quality Specifications Family WS-Quality Model
defines an abstract model in order to define Web Services quality
WS-Quality Use Case
provides a number of use cases as best practices that Web Services quality associates could be faced with in the process of developing Web Services
WS-Quality Factors
defines a list of non-functional properties of Web Services in which represents and valuates the quality of Web Services
WS-Quality Description Language
provides a basic description language in XML to describe of Web Services quality for exchange between Web Service quality associates
WS-Quality Test Guideline
provides a guideline and detailed mechanisms to test and measure the quality level of Web Services
WSQM – 5 family specifications
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WS-QF (Web Service Quality Factor)
Business ValueQuality Group
Business Value QualityBusiness Value Quality
SuitabilityService Cost EffectEffect Recognition levelRecognition level
Service MeasurementQuality Group Service Level Measurement QualityService Level Measurement Quality
PerformancePerformance StabilityStability
System InformationQuality Group
InteroperabilityInteroperability
ConformabilityConformability InteroperabilityInteroperability
Business ProcessingBusiness Processing
Message ReliabilityMessage Reliability TransactionTransaction CollaborabilityCollaborability
ManageabilityManageability
IntrospectionIntrospection ControlControl NotificationNotification
SecuritySecurity
ConfidentialityConfidentiality IntegrityIntegrity AuthenticationAuthentication
Access ControlAccess Control Non -repudiationNon -repudiation AccessibilityAccessibility
Audit trailAudit trail PrivacyPrivacy
Business ValueQuality Group
Business Value QualityBusiness Value Quality
Service Cost Recognition level
Service MeasurementQuality Group Service Level Measurement QualityService Level Measurement Quality
PerformancePerformance StabilityStability
System InformationQuality Group
InteroperabilitySuitability for Standards
ConformabilityConformability InteroperabilityInteroperability
Business ProcessingBusiness Process Quality
Message ReliabilityMessage Reliability TransactionTransaction CollaborabilityCollaboration
ManageabilityManageability Quality
Management Informationofferability ControlControlability NotificationNotification
SecuritySecurity Quality
ConfidentialityConfidentiality IntegrityIntegrity AuthenticationAuthentication
Access ControlAccess Control Non -repudiation-Non-repudiation AccessibilityAccessibility
Audit trailAudit PrivacyPrivacy
Service Suitability Service Aftereffect Recognition levelService Brand Value
PrivacySing-Sign-On
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WS-QF (Web Service Quality Factor)
Business Value Quality
Service Cost : a level of payment for value
Service Suitability : Is a particular service suitable for business operation?
Service Aftereffect : quantitatively or qualitatively expresses effect from a
particular web service in business
Service Brand Value : collection of reputation shaped by users
Service Level Measurement Quality
Performance : response time to a service request
Stability : How stable web services provide services?
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Suitability for Standards
Conformability : to evaluate if web services was built according to the
standards
Interoperability : how well service information can be exchanged and
used?
Business Process Quality
Message Reliability : to exchange without any errors
Transaction Process Ability : ability to process related tasks on process
flow
Business Process Collaboration Ability : How well is the collaboration
scheme with Web Services suitable to business process
WS-QF (Web Service Quality Factor)
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Manageability QualityManagement information offerability Observability : feature to provide the management informationControlability : feature to change the inside information
Security qualityConfidentialityIntegrityAuthenticationAccess controlNon-repudiationAvailabilityAuditPrivacySing-Sing on
WS-QF (Web Service Quality Factor)
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Next Step
Applying WSQM in multiple sets of government guidelines, recommendations, and standards
Providing of quality information from WSQM test bed
Collaboration between national Web Services Registry
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Consideration for Collaboration between EERP and WSQM
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A table of contents
Core Technology of EERP
Consideration 1: Service granularity
Consideration 2: Weight for quality factor
Consideration 3: How to get quality Info.
Consideration 4: How to use quality info
Consideration 5: Common Service Quality
Consideration 6: Quality Chain
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Quality of Service: Framework- QoS description, evaluation, audition, mapping..
Dynamic Service Orchestration: Control- Resource optimization
eXtensible Web Service Description: Representation- extension of WSDL with QoS and semantic expressions of
service functions
Granularity of Service: Composition- Search the optimized unit of services
Core Technology of EERP
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WSQM focuses on quality factors of simple type service. EERP varies service granularity flexibly.
Considerations: Is WSQM proper model for various granularity of services? What part of WSQM or WSQDL should be changed for reflecting granularity?
Consideration 1: service granularity
Composite service
Single or simple service
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Various quality factors for services. What is the major or minor factors for EERP selecting a service?
Each business requires different level of weight of quality factor for selecting a service. Now, WSQDL has no information of weight for quality factor.
Consideration 2: Weight for quality factor
UDDI for quality info
priority factor weight
1 Security 50
2 Interop 30
3 Metric 20
Service consumer 1
priority factor weight
1 Metric 40
2 Interop 40
3 Security 20
Service consumer 2
WSQDL 1
WSQDL 2
WSQDL 3
WSQDL n
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Getting time for quality information is different as quality factors. For completing WSQDL, it requires getting information carefully in each step and framework for collecting quality info. - Business related Info(cost, suitability,..): before running or after runn
ing
- Operational related Info(measurement): while running
- Technical related Info(Interop, security..): before running
Consideration 3: How to get quality Info.
Services for Biz
Use the service
Suitable for Biz purpose?
Satisfy QoS inTech?
Is it possibleWrapping or alternative?
Yes Yes
No
No use
No
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EERP Dynamic service orchestration requires real-time service search with quality info. For the purpose, we use UDDI which has quality classification and updates it with the help of service quality management system.
Consideration 4: How to use quality info
WS QualityManagement
System
WS QualityInfo
WS Provider
① WS registration
② request new WS
③ provide WSDL of new WS
WS
④ test with Agent
⑤ Store Quality Info
connecting API
⑦ store the ref of WS Quality
⑥ provide WS Quality Info
UDDI
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Each WS could be reclassified according to quality grade.
Because there are various quality factors, we need quality context for describing quality values. EERP system can find services more rapidly if WS is categorized in quality context.
Consideration 4: How to use quality info
Quality Management System
WSDL 1
Quality context 1 value
Quality context 2 value
Quality context 3 value
WSDL 2
Quality context 1 value
Quality context 2 value
Quality context 3 value
WSDL 3
Quality context 1 value
Quality context 2 value
Quality context 3 value
WSQDL
Metric Eval Biz Proc Biz Val
Interop Sec Manage
Secrecy Non-rep
UDDI
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In EERP, Some services could be packed for common service. In this case, users have more interest in service quality of packing unit more than each unit service.
If WSQDL support this type quality model, it makes quality system more simple.
Consideration 5: Common Service Quality
WSQDL 1 WSQDL 2
Common Service Pack 1
PS 1
PS 2
PS 3
Common Service Pack 2
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The value of each quality factor is described in quality chain, in which each factor can refer the other factor.
Quality factor is composed of measure factor, evaluation factor, biz process factor, and biz value factor.
EERP can refer quality chain info for selecting a service
Consideration 6: Quality Chain
Target Web services
Quality Factor
Biz process factor
Eval factor
Biz value factor
Measure factor
Property Sub property Function Performance
Sub factor
Sub factor Property Appraisal
Sub factor Property Function Performance
Metric
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If services are classified with business purpose and grouped in same quality context, we can find a service suitable for a situation.
Single value or value bandwidth for an item on quality chain is possible.
Consideration 6: Quality Chain
eval/security/XML-enc
keySize: 128
secAlgorithm: RSA
encTime: 10ms-20ms
S1 S2 S3 S4 S5
Common value for quality factor
Quality factor value in bandwidth
Same purposeservices