Upload
hafwen
View
32
Download
0
Embed Size (px)
DESCRIPTION
Dynamic Web Service Selection for Workflow Optimisation . Lican Huang, David W. Walker, Yan Huang, Omer F. Rana Presented by Lican Huang . School of Computer Science, Cardiff University. AHM2005 21 Sept, 2005. - PowerPoint PPT Presentation
Citation preview
Dynamic Web Service Selection for Workflow
Optimisation
Lican Huang, David W. Walker,
Yan Huang, Omer F. Rana
Presented by Lican Huang School of Computer Science, Cardiff University
AHM2005 21 Sept, 2005
Outline
•Introduction
• Framework • Implementation
•Conclusion & Future work
AHM2005 21 Sept, 2005
WOSE Project (Workflow Optimisation Services for e-Science Applications)
Funded by the EPSRC
Cardiff University, Imperial College and Daresbury Laboratory
Primary investigator: David.W.Walker
.
Introduction--background
AHM2005 21 Sept, 2005
Introduction-- motivation
(1)Multiple copies of a service with different performance or other user defined set of criteria; and these services cannot be selected at design time because their performance is not known at that time.
(2)workflow optimisation by selecting optimal web services at run-time and integrating dynamic selection of web service into workflow
(2) fault-tolerance by trying a set of candidates of services
(3) Logging data for analysis of workflow results
AHM2005 21 Sept, 2005
Introduction-- Issues of concern
(1) mechanisms to discover, select and invoke Web services dynamically
(2) mechanisms to optimize workflow by integrating the selection of service into workflow
AHM2005 21 Sept, 2005
Framework --Architecture of dynamic Web services selection for workflow optimisation
AHM2005 21 Sept, 2005
Discovery Service
History Database
Registry (UDDI)
Monitoring Tool
Optimization Service
Proxy Service
Monitor service
Framework --Message sequence of workflow incorporating dynamic Web Service selection
AHM2005 21 Sept, 2005
Optimisation Service
5. List of services
6. Selected service
Workflow script
Workflow deploy
XSLT converter
2. Dynamic invocation through proxy
9. Result through proxy
3. Service query
4. List of services
7. Invoke service
8. Result
Discovery ServiceProxy Service
1. Request 2A. Direct invocation
3A. Direct result
10. Result
Web serviceWorkflow engineWOSE client
Framework– proxy as adaptor of dynamic selected service
AHM2005 21 Sept, 2005
Service A
Proxy service
Service B
Service B1Service B2Service B3
Service B4
Service B5
Framework– proxy service
• Proxy service
• Discovery service
• Optimisation service
• monitor service
• Dynamic invocation service
AHM2005 21 Sept, 2005
Framework– proxy service interface
<wsdl:message name ="ServiceProxyResponse"> <wsdl:part name ="ServiceProxyReturn" type="xsd:string" /> </wsdl:message><wsdl:message name = "ServiceProxyRequest"> <wsdl:part name ="servicemeta“ type="xsd:string"/> <wsdl:part name ="querymethod" type="xsd:string" /> <wsdl:part nam =" optimizationMETA " type="xsd:string"/> <wsdl:part name ="optimizationMode" type="xsd:string“/> <wsdl:part name ="operation" type="xsd:string" /> <wsdl:part name ="parameters“ type="xsd:string" /> </wsdl:message>
AHM2005 21 Sept, 2005
Framework– fault-tolerance and logging
AHM2005 21 Sept, 2005
Public String ServiceProxy(…){ Set values of uddiregistries; Servicelist = discoveryService(… ); While (true) { Service= Optimizationservice(Servicelist); If result =dynamicInvoke(service) fails{ Updates fail-timestamp in Database; Logging; } else { Update average_response_time in database; Logging; Stop; } } Return result; }
Framework– discovery service interface
<wsdl:message name="ServiceDiscoveryResponse"> <wsdl:part name="ServiceDiscoveryReturn" type="xsd:string" /> </wsdl:message> <wsdl:message name="ServiceDiscoveryRequest"> <wsdl:part name="servicemeta" type="xsd:string" /> <wsdl:part name="querymethod" type="xsd:string" /> <wsdl:part name="uddiregistries" type="xsd:string" /> </wsdl:message>
AHM2005 21 Sept, 2005
Framework– discovery methods
Public string ServiceDiscovery (String servicemeta, querymethod, String uddiregistries){Switch querymethod Case byNAME Look up the matched service name in uddiregistry(ies) Case byMETA Look up the matched metadata in the description entity of businessService entity of uddiregistry(ies). Case byONTOLOGY Look up the URL of semantic definition XML File and matchmake the semantically equivalent service. }
AHM2005 21 Sept, 2005
Framework– discovery by name
•Typically used where services are registered by the same business entity but with different access points .
•No extensions are needed to the information contained in the UDDI registry
AHM2005 21 Sept, 2005
Framework– discovery by metadata UDDI extensions
<businessService serviceKey =”37B49950-90A0-11D9-9950- BB91FEE6D433” businessKey = “5D4F01A0-8FE2-11D9-81A0-832EB7272640” > <name>blastallservice</name> <description> <wosemeta serviceName= “blastallservice" serviceID="1239-3514-6196-8373"/> </wosemeta> </description> <description> <wosemeta operationName =“serviceblastall" operationID="1351-3612-7812-9156"> <inputype>string</inputtype> <outputtype>string</outputtype> </wosemeta> </description> … </businessService>
AHM2005 21 Sept, 2005
Framework– discovery by ontology UDDI extensions
<<businessService serviceKey =”14E69DE0-D28D-11D90-80990AF8150A” businessKey = “7D92E5E0-D1C2-11D9-A5E0-CF2D2BB38AE7” > <name>blastallservice</name> <description> <woseOntology> http://131.251.47.147:8080/axis/blastall.xml </woseOntology> </description> … </businessService>
AHM2005 21 Sept, 2005
Framework– optimisation service interface
<wsdl:message name="ServiceOptimizationRequest"> <wsdl:part name="serviceURL" type="xsd:string" /> <wsdl:part name="optimizationMode" type="xsd:string" /> <wsdl:part name="optimizationMETA" type="xsd:string" /> </wsdl:message><wsdl:message name="ServiceOptimizationResponse"> <wsdl:part name="ServiceOptimizationReturn" type="xsd:string" /> </wsdl:message>
AHM2005 21 Sept, 2005
Framework– optimisation service uddi extensions
<wsdl:message name="ServiceOptimizationRequest"> <wsdl:part name="serviceURL" type="xsd:string" /> <wsdl:part name="optimizationMode" type="xsd:string" /> <wsdl:part name="optimizationMETA" type="xsd:string" /> </wsdl:message><wsdl:message name="ServiceOptimizationResponse"> <wsdl:part name="ServiceOptimizationReturn" type="xsd:string" /> </wsdl:message>
AHM2005 21 Sept, 2005
Framework– monitor service interface
- <wsdl:message name="servicemonitorRequest"> <wsdl:part name="monitorType" type="xsd:string" /> </wsdl:message>- <wsdl:message name="servicemonitorResponse"> <wsdl:part name="servicemonitorReturn" type="xsd:string" /> </wsdl:message>
AHM2005 21 Sept, 2005
Get CPU load and CPU speed
Framework– optimisation criteria
- performance factor= (1- CPU load)*CPU_speed/1000
AHM2005 21 Sept, 2005
Framework– optimisation service
-Performance {-While ( service in servicelist)-{ - performance_factor= monitorservice(); if (performance_factor_max< performance_factor) performance_factor_max = performance_factor; } return service location with max performance_factor}
AHM2005 21 Sept, 2005
Framework– optimisation modes
Public string ServiceOptimization (String serviceURL, String optimizationMode, String optimizationMETA){ Swith optimizationMode Case byPERFORMANCE Look up real-time computer load,etc. and history data. Case byTRUST Look up the trustworthiness of the services. Case byPersonalization Look up the user defined set of criteria }
AHM2005 21 Sept, 2005
Implementation– environment
Operation systems: linux, windowsWeb service container: Tomcat + AXISWorkflow engine: ActiveBEPLWorkflow languages: SCUFL, BPEL4WSDatabase: mySQLUDDI: JUDDI at Welsh e-Science CentreMachines: ygrid01, ygird01, ygrid03,ygrid04,ygrid05,ygrid06,(linux) desktop linux, laptop windows
AHM2005 21 Sept, 2005
Implementation – example
AHM2005 21 Sept, 2005
Implementation– request
AHM2005 21 Sept, 2005
Implementation– result
AHM2005 21 Sept, 2005
Implementation– monitor logging data
CCGrid2005 Wip section12 May, 2005
Implementation– proxy service logging data
CCGrid2005 Wip section12 May, 2005
Conclusion
AHM2005 21 Sept, 2005
1. Present framework for dynamic web service selection within a workflow session
2. Proxy service as adaptor of dynamic selected service
3. Strategy for discovering service by UDDI extensions.
4. Performance service selects optimal service among services by getting real-time data with monitoring service
5. Implementation of the framework
Future work
AHM2005 21 Sept, 2005
1. Optimisation model 2. Discovery service by ontology
method
AHM2005 21 Sept, 2005
Thanks
Questions?