A Link-Based Ranking Model for Services
Camelia Constantin1 Bernd Amann1 David Gross-Amblard2
1LIP6Universite Pierre et Marie Curie Paris
2Laboratoire CEDRICC.N.A.M. Paris
Cooperative Information Systems(CoopIS 2006)
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 1 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Distributed Applications
Observation
Service-oriented computing and P2P architectures are more andmore popular for building web applications
Many web applications are based on distributed data andprocessing
Central Issue
Controlling (estimating and improving) the quality of manydistributed applications
Our Approach
Rank services according to the estimated influence of their qualityon the global quality of applications
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 2 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Outline
Introduction
ContextMotivating ExampleRelated WorkApproach
Model
Quality ContributionService UsageEffective Contribution
Importance Computation
Service ImportanceExperiments
Conclusion and Future Work
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 3 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Data-Intensive Services
Web Service:Parameterized Query (SQL, XQuery) over local and remote data sending aset of data as response
S4
S5
S3
S1
S2
S6
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 4 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Data-Intensive Services
Web Service:Parameterized Query (SQL, XQuery) over local and remote data sending aset of data as response
S4
S5
S6
S3
S1
S2
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 4 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Data-Intensive Services
Web Service:Parameterized Query (SQL, XQuery) over local and remote data sending aset of data as response
S4
S5
S6
S3
S1
S2
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 4 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Data-Intensive Services
Web Service:Parameterized Query (SQL, XQuery) over local and remote data sending aset of data as response
S4
S5
S6
S3
S1
S2
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 4 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Data-Intensive Services
Web Service:Parameterized Query (SQL, XQuery) over local and remote data sending aset of data as response
S4
S5
S6
S3
S1
S2
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 4 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Data-Intensive Services
Web Service:Parameterized Query (SQL, XQuery) over local and remote data sending aset of data as response
S4
S5
S6
S3
S1
S2
Important services : those which contribute the most
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 4 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Example: Ranking of ServicesRanking Model
S4
S5
S6
S3
S1
S2
S6 > S4 > S3 >
S5 >S2=S1
> > >
Applications:
Search engines (services, data)
Service configuration → replicate S6
Pricing: should be more expensive thanC.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 5 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
State of the artRanking of Web Services
Sampling-based ranking of data-intensive services with respect to aspecific client [Caverlee et al, ’04]
Recommendation-based techniques (user feedback and voting services)[Abbadi et al, ’04], [Kalepu et al, ’04]
Conformance of Services’QoS published features during given periods[Aberer et al, ’05]
−→ Do not consider the collaboration links between services
Link-based Ranking of Web Pages
Consider the web pages and the links between them as a graph (eg.Google’s PageRank[Page et al, 98], HITS [Kleinberg, 99])
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 6 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
State of the artRanking of Web Services
Sampling-based ranking of data-intensive services with respect to aspecific client [Caverlee et al, ’04]
Recommendation-based techniques (user feedback and voting services)[Abbadi et al, ’04], [Kalepu et al, ’04]
Conformance of Services’QoS published features during given periods[Aberer et al, ’05]
−→ Do not consider the collaboration links between services
Link-based Ranking of Web Pages
Consider the web pages and the links between them as a graph (eg.Google’s PageRank[Page et al, 98], HITS [Kleinberg, 99])
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 6 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
State of the artRanking of Web Services
Sampling-based ranking of data-intensive services with respect to aspecific client [Caverlee et al, ’04]
Recommendation-based techniques (user feedback and voting services)[Abbadi et al, ’04], [Kalepu et al, ’04]
Conformance of Services’QoS published features during given periods[Aberer et al, ’05]
−→ Do not consider the collaboration links between services
Link-based Ranking of Web Pages
Consider the web pages and the links between them as a graph (eg.Google’s PageRank[Page et al, 98], HITS [Kleinberg, 99])
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 6 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
ContextMotivating ExampleRelated WorkApproach
Adapting PageRank for Ranking Services
Web Page graph −→ Service graph:
Web page −→ service web and hyperlink −→ service call?
Some important differences:
Service is generally a ”black-box” for the clientsService does a computation on behalf of its caller, returns a resultMore complex quality criteria for services (eg. response time)Hyperlinks=static follow-up links, calls=dynamic usage of services
Our model
Considers both static (quality contribution) and dynamic (serviceusage) links between services
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 7 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Example: Data-Intensive Services
S4
S5
S6
S3
S1
S2
How to compute the contribution scores for each service?
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 8 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Quality Contribution Score
The quality of Si depends on the quality of all services Sj that it uses
Semantic and static measure, similar to hyperlinks
Computed independently on the calls between services
Estimated locally by si for all services sj that it calls
Score cji ∈ [0, 1] comparing the contribution of all services Sj to Si
∑
sj
cji = 1
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 9 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Quality Contribution Score
The quality of Si depends on the quality of all services Sj that it uses
Semantic and static measure, similar to hyperlinks
Computed independently on the calls between services
Estimated locally by si for all services sj that it calls
Score cji ∈ [0, 1] comparing the contribution of all services Sj to Si
∑
sj
cji = 1
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 9 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Example: Static Query Analysis
S3 estimates the static contribution of S4, S5, S6 to its quality
S4
S5
S6
S3
S1
S2
−→ S4 contributes the most, S5 contributes the least
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 10 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Example: Static Query Analysis
S3 estimates the static contribution of S4, S5, S6 to its quality
S4
S5
S6
S3
S1
S2
0.1
0.4
0.5
−→ S4 contributes the most, S5 contributes the least
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 10 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Service Usage Score
Si uses Sj
Dynamic measure expressing the way in which Sj is used by Si
Usage function uji(t) ∈ [0, 1] computed locally by Si for each Sj
Based on information registered in the log (Logi ) of Si during aperiod
Example
Age/freshness of the results of Sj
The part of the results of Sj missed by Si
The percentage of the results of Sj that are useful to Si
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 11 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Example: Percentage of Useful Results
S3 computes the service usage of S4, S5, S6 by observing the usageof their results
S4
S5
S6
S3
S1
S2
−→ S5 is not used, S6 is more used than S4
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 12 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Example: Percentage of Useful Results
S3 computes the service usage of S4, S5, S6 by observing the usageof their results
S4
S5
S6
S3
S1
S2
−→ S5 is not used, S6 is more used than S4
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 12 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Example: Percentage of Useful Results
S3 computes the service usage of S4, S5, S6 by observing the usageof their results
S4
S5
S6
S3
S1
S2
100%
50%
−→ S5 is not used, S6 is more used than S4
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 12 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Effective Contribution ScoreServices effectively contribute to the quality of others only if they are called
S4
S5
S6
S3
S1
S2
0.5
0.1
0.4
−→ Static contribution of S5 is smaller than the one of S6
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 13 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Effective Contribution ScoreServices effectively contribute to the quality of others only if they are called
S4
S5
S6
S3
S1
S2
50%
100%
−→ Service usage of S5 is greater than the one of S6
−→ Service usage of S5 is 0
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 13 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Effective Contribution ScoreEffective contribution=quality contribution * service usage(ceff
ji (t) = cji ∗ uji(t))
S4
S5
S6
S3
S1
S2
*
*
x
0.5*(50%)
0.1*0%
0.4*(100%)
−→ effective contribution of s5 is greater than the one of s6
The contribution of sj to si is maximized when service usage is 1
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 13 / 21
IntroductionModelImportance ComputationConclusion
Quality ContributionService UsageEffective Contribution
Summary
Contribution scores computed by Si for services Sj that it uses:
Score Description Si → Sj Sk → Si → Sj
(See Paper)
static distribution cji —contributionservice usage weight uji(t) ∈ [0, 1] ujik(t) ∈ [0, 1]
effective weighted cji ∗ uji(t) cji ∗ ujik(t)contribution distribution
Contribution links have a static and a dynamic part
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 14 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Total contribution
S4
S5
S6
S3
S1
S2
effective contribution
S3 has a local knowledge on the effective contribution of S4,S5,S6
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 15 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Total contribution
S4
S5
S6
S3
S1
S2
effective contributioneffective contribution
S1 and S2 have local knowledge on the effective contribution of S3
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 15 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Total contribution
S4
S5
S6
S3
S1
S2
effective contributioneffective contribution
Ex: How to compute the effective contribution of S4 to all others?
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 15 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Importance
Importance of a Service
Total effective contribution to the quality of other services
Importance Computation
Static contributions −→ C (Contribution matrix)
Log+C −→service usage E (Effective contribution matrix)
The importance is the solution of a linear system with matrix E
AlgorithmsCompute the importance by iterative algorithms:
E →Algorithms Service Importance
Computation stops at convergence
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 16 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Algorithms
Centralized Iterative Algorithm
Single service that gets the contribution values from all others
Builds matrix E and computes the importance
→ Computing service must get possibly secret information from others
Distributed Iterative Algorithms
Each service computes its importance by exchanging messages
Synchronous: all services compute the same iterationAsynchronous:
Computation messages are sent asynchronously, at the same timeas the call parameters during normal service callsEach service computes different iterations and updates theirimportance at each call
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 17 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Number of Messages for Different Graph ModelsGraph configurations generated by four methods:
Max, Linear-Copying, Small-World, Client-Server.
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 18 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Number of Iterations for Different Usage Functions
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 19 / 21
IntroductionModelImportance ComputationConclusion
Service ImportanceExperimets
Converged Services w.r.t. Number of Iterations
(a) synchronous algorithm (b) asynchronous algorithm
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 20 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Conclusion and Future Work
Contributions:
Link-based ranking model for servicesCan be applied to different quality measuresExpresses the quality contribution and usage between services
Importance Computation:Distributed computation, each service computes its own importanceTwo algorithms: a synchronous and an asynchronous oneSimulation of importance computation on four service graphs
Future Work:
Ongoing implementation on ActiveXML (WebContent, lot 5 - P2P).Apply importance scores for P2P optimisation:
Optimize the global response time of distributed queriesP2P data refresh strategies
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21
IntroductionModelImportance ComputationConclusion
Thank you for your attention
C.Constantin, B.Amann, D.Gross-Amblard (Universit e Paris VI et C.N.A.M)A Link-Based Ranking Model for Services CoopIS 2006 21 / 21