1 wsqdl (web service quality description language) 16 th april, 2007 youngkon lee korea polytechnic...
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WSQDL(Web Service Quality Description Language)
16th April, 2007
Youngkon LeeKorea Polytechnic University
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A table of contents
What is WSQDL?
Background
Needs
What is WSQM?
What is WS Quality Factor?
WSQF – analysis
Concept of Quality Chain
Principle of Design
Complex type
Conclusion
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What is WSQM TC?
Purpose: to establish Web services quality model and its necessary
specifications
Scope: quality factor, quality associates, and quality activity, quality
test guideline, quality description language for Web services
Members: Korea Government side (NIA, ETRI), Korea SI and IT
companies, DERI, etc
WSQDL WSTG
WSQM
WSQF WSQUC
Core Spec.
Subsidiary Spec.
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What is WSQDL?
XML schema for describing values of Web service quality factors with
measuring/evaluation method, condition factors in specified and
normalized form by Web service associates.
Configuring quality factors
Specifying quality factor description
Web services Web serviceQuality Model
(WSQM)
Web serviceQuality DescriptionLanguage (WSQDL)
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Background
Requirements for Web service quality according to Web service
proliferation
ex: needs in Korea e-Government project
Needs of specification for describing Web service quality model(WSQM)
Motivation for activating quality activity of Web service associates
Quality Requirement
Activating quality activity
Specification for WSQM
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Needs
Describing value of Web service quality factors in specified form
Automatic exchange of quality data
use of WSQDL objectively for quality activity ex) SLA
help to make consensus between Web service associates ex)
negotiation/contracts
Automaticexchange ofquality data
ObjectiveData forQualityactivity
MakingConsensus
between Web service
associates
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What is WSQM (Web Service Quality Model)?
A model for configuring Web service quality or differentiating servicelevel It consists of 3 components: Quality Factor, Quality Associate, andQuality Activity.
Quality Factor: fundamental components that recognize Webservices 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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What is WSQF (Web Service Quality Factor)?
WSQF refer to
a group of
items for
representing
and valuing
the quality of
Web services.
WSQF can be
divided into 3
groups in the
point of use by
user.
Business ValueQuality Group
Business Value QualityBusiness Value Quality
SuitabilitySuitability 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
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WSQF - Analysis
Group possibly the quality factors by following criteriafunctionality: function implemented, performance of functionCorrespondence to user requirementsEvaluation timeWhether there is evaluation criteria or not ex) WS-I BP, BSPComplexity: single criteria or multiple criteria
Quality factor
Measurablefactor
Evaluationfactor
• Availability
• Accessability
• Successability
• Response time
• Throughput
Evaluationcriteria
No evaluationcriteria
• Security
• Interoperability
• Biz Process
• Management
• Biz Value
• service price
• service suitability
• service effect
• service brand value
Single criteria
Multiple criteria
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WSQF – Business value factor
Quality Factor
Sub Factor Evaluation
service price
service suitability
service effect
service brand
Biz value
Property
price, penalty, compensation biz suitability, convenience
biz effect, ROI
recognition, reputation
survey
user evaluation
index calculation
survey, interview
Value endowed by Web service user subjectively or objectively in the
viewpoint of business
Subjective sub-factors: evaluating the value of factors by survey or
interview, ex) reputation, recognition
Objective sub-factors: evaluating them quantitatively, ex) price,
ROI, business effectiveness
Changed much by strategy, goal, core value, etc
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Quality factor
Property
confidentiality
certification
Integrity
non-repudiation
Security
Function
XML ENC
SAML, X.509
XML ENC DSIG
XML DSIG
Performance
security level
interoperability
throughput
throughput
Sub property
message level confidentialitymessage level certificationmessage levelintegritymessage level non-repudiation
Quality factor required for securing Web service system
Properties: confidentiality, certification, integrity, non-repudiation
Sub properties: message level or communication protocol level
Performance: security level, processing speed,
interoperability,etc.
WSQF – Security factor
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Quality Factor
Property Function Evaluation
message conformity
WSDL conformity
UDDI conformity
Interoperability SOAP Handler
WSDL I/F
UDDI Registry
WS-I satisfaction degree
Quality for guaranteeing the technical consistency between Webservice systemRatio or number of rules in WS-I BP, BSP satisfied by a Web service systemConsider severity (Must, Should, May) level of rule
WSQF – Interoperability factor
WS-I satisfaction degree
WS-I satisfaction degree
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Quality Factor
SubFactor Function Performance
Throughput
Response Time
Accessability
measure factor
# of trans/sec
millisecond
rate
Successability
Availability
rate
rate
Quality for representing technical performance of Web service
system
Consideration
What is the items measured?
How can we measure it?
How do we calculate measured value for result?
WSQF – Measurement factor
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Quality Factor
Sub Factor Property Function
reliable message
transaction processing
BP collaboration
biz processing AtMostOnce,…
ACID
Compensable
Retry, Ack
2PC
Context Mgmt
Performance
throughput
interoperability
security
Quality factor for applying Web service to real business area
Message reliability: transmission guarantee, duplicated message
removal, message ordering
Transaction processing: Atomic Transaction, Long-term Biz Activity
BP collaboration: Interoperability, Throughput, response time ,Error
Handling, Recovery, compensability
WSQF – Business processing factor
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Quality Factor
Property Function Performance
• introspectability
• controllability
• notifiability
• manageability • Tracking,Logging
• Resource Managing
• Subscription
• security
• response time
• interoperability
Quality factor representing how well Web service can manage other Web service or computing resources
Introspectability: manageable interface, # of metric inform,rapidity, securitycontrollability: controllable interface, # of control items, rapidity,securityNotifiability: notification interface, # of event type covered,rapidity, security
WSQF – manageability factor
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Concept of Quality Chain
: chain of dependency
Interoperabilityfactor
Biz processingfactor
Measurementfactor
ManageabilityfactorSecurity
factor Biz valuefactor
Configuration of dependency between Web service quality factorsEx) The performance of security factor can be presented asinteroperability or metric value. Biz value quality is evaluated on the basis of other technicalquality factors by users.
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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
Security, manageability, interoperability can be grouped as evaluation
factor structured pattern.
The performance factor of biz process factor can be presented as
evaluation factor and measurement factor
Evaluation factor can be presented as itself recursively or measure factor
Concept of Quality Chain
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Principle of Design
Consistency of describing various factors
Convenience: Reference by global complex type and elements
Representation: recursive structure for representing quality chain
Conformity: representation of specification conformity
Flexibility for expanding coverage
Consistency RepresentationConvenience
Conformity flexibility
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Complex type – Web service type
Complex type for representing Web service as a target evaluated
One service described in a WSDL is a minimum evaluation unit.
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Composed of 4 major factors: Measurement factor, Biz value factor,
evaluation factor, Biz process factor
Each factor can be referenced in the other factors.
Complex type – Quality factor type
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Global data type for representing measurement factor.
Composed of measuring method, condition variable, measuring
function, metric value.
Complex type – Metric type
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Global data type for representing evaluation factor Composed of sub property, function, and descriptionFunction is composed of conformity, performance, and parameterPerformance has evaluation factor or measurement factor recursively
Complex type – Property type
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Represents whether a function has conformity with a specification
Composed of specification, rule category conformity, and overall conformity
Complex type – Conformity type
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Complex Type - Appraisal Type
UserAppraisalType has WSUser and Appraisals. WSUser describes information of user evaluating Web service Appraisals have Appraisal as evaluation itemAppraisal is a type of evaluation degree type, which has item, value, unit, perfect score, description
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Conclusion
WSQDL is a new specification for describing Web service quality
formally.
WSQDL probably activate business action between Web service
associates by enabling transmission of specified quality data
We have a plan to apply WSQDL to Web service test-bed in Korea
Government side for communicating quality information.
We have a plan to improve WSQDL to present OASIS standard and t
o expand it to cover SOA service level.