Post on 21-Jan-2016
ENABLING ADAPTABILITY IN COMPOSITE SERVICES USING ENABLING ADAPTABILITY IN COMPOSITE SERVICES USING TRANSPARENT SHAPING TECHNIQUESTRANSPARENT SHAPING TECHNIQUES
Onyeka Ezenwoye
Autonomic Computing Research Laboratory
School of Computing and Information Sciences
Florida International University
http://www.cs.fiu.edu/~oezen001
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
OvervieOverview:w:Motivation
Background
Our Approach
Solutions
Related Work
Future Work
Conclusion
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The TrendThe Trend
Organizations need to integrate applications and data with other divisions, customers, partners, etc.
Service aggregation
OvervieOverview:w:Motivation
Production
Service
Customer Customer
Accounting
Service
Inventory
Service
Delivery
Service
Sales ServiceSales Service(a workflow)
Background
Our Approach
Related Work
Future Work
Conclusion
Solutions
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The Trend The Trend (2)(2)
High-level composition languages and tools.
OvervieOverview:w:Motivation
Graphical Modeling Environment
<process name="google-amazon" > <variables> <variable name="requestMessage"/> </variables> <assign name="AssignVariables"> <copy> <from part="author"/> <to part="phrase"/> </copy> </assign> <receive operation="input"/> <invoke inputVariable="ItemMsg"> <target linkName="Link66"/> <source linkName="Link61"/> </invoke> <reply operation="input"> <target linkName="Link61"/> </reply></process>
Language GrammarBackground
Execution Engine
Our Approach
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The Trend The Trend (3)(3)
Grid: share resources for the purpose of coordinated problem solving.
OvervieOverview:w:Motivation
Interaction between components
institutional boundary
application resource
Background
Our Approach
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The ProblemThe Problem
OvervieOverview:w:Motivation
Domain expert does not need to know about:
•Service oriented architecture
•Web services
•Fault-tolerance
•Adaptability
Background
Our Approach
Related Work
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Conclusion
Solutions
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
OvervieOverview:w:
Background
Motivation
Our Approach
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Web servicesWeb services
OvervieOverview:w:Motivation
Background
A Web service is an application that is accessible over the internet.
Java RMIApp 1 App N…
Enterprise A
Enterprise B
Enterprise C
Enterprise D
Internet
.NETApp 1 App N…
etc.App 1 App N…
Core Technologies:•WSDL (Web Service Description Language)•SOAP•UDDI (Universal Description Discovery and Integration)
Our Approach
Related Work
Future Work
Conclusion
Solutions
CORBAApp 1 App N…
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Web services Web services (2)(2)
OvervieOverview:w:Motivation
Background
Subscribe Publish (WSDL)
SOAP
Service Consumer
Client
Service Provider
Service
UDDI Registry
WSDL
Legendrequest flow
reply flow
program boundary
module boundary
SOAP
Service Description
WSDL
Our Approach
Related Work
Future Work
Conclusion
Solutions
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Composition LanguageComposition Language Business Process Execution Language (BPEL)
– BPEL is workflow language for composing aggregate Web service
– A BPEL process is defined in terms of its interactions with partners.
OvervieOverview:w:Motivation
Background
Our Approach
Related Work
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Conclusion
Solutions
BPEL Composition
UDDI Discovery
WSDL Description
SOAP Message
XML Encoding
Production
Service
Customer
Accounting
Service
Inventory
Service
Delivery
Service
Sales ServiceSales Service(BPEL Process)
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BPELBPEL
OvervieOverview:w:Motivation
Background
Service
Service
Service
ServiceBPEL
Process
Service Interface Message flow
Workflow Design– Graph Structure
Support for iterations, loops
Data Movement– Centralized.
Our Approach
Related Work
Future Work
Conclusion
Solutions
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BPELBPEL
OvervieOverview:w:Motivation
Background
Service
Service
Service
ServiceBPEL
Process
Service Interface Message flow
Workflow Design– Graph Structure
Support for iterations, loops
Data Movement– Centralized.
Our Approach
Related Work
Future Work
Conclusion
Solutions
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BPELBPEL
OvervieOverview:w:Motivation
Background
Service
Service
Service
ServiceBPEL
Process
Service Interface Message flow
Workflow Design– Graph Structure
Support for iterations, loops
Data Movement– Centralized.
Our Approach
Related Work
Future Work
Conclusion
Solutions
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BPEL ChallengesBPEL Challenges Fault tolerance
– Limited– Has fault and event handlers– Supports compensation handling
Not modular to support– Separation of concerns– Maintainability– Evolution
BPEL is not dynamic– No runtime workflow alteration for optimization or
fault-tolerance
OvervieOverview:w:Motivation
Background
Our Approach
Related Work
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
OvervieOverview:w:Motivation
Our Approach
Background
Related Work
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Conclusion
Solutions
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Our ApproachOur Approach Transparent Adaptation
– allows introduction of new code (component) at run-time
– does not tangle code for adaptive behavior with original application (separates functional code from non-functional code)
– preserves desirable original behavior– adaptation is transparent to the original code (the
original code is unaware of the adaptation)
OvervieOverview:w:Motivation
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Our Approach
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Our Approach Our Approach (2)(2)
Encapsulate BPEL activities with generic hooks.
Hooks will point to “proxy” Web Service. Fault tolerance and adaptation will be
provided through Proxy service Fault tolerance
Retry Alternate resource
OvervieOverview:w:Motivation
Background
Our Approach
Related Work
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Solutions
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Our Approach Our Approach (3)(3)
OvervieOverview:w:Motivation
Service
Service
BPELProcess
Service Interface Message flow
Related Work
Future Work
Conclusion
Solutions
Background
Our Approach
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Our Approach Our Approach (3)(3)
OvervieOverview:w:Motivation
Service
Service
BPELProcess
Service Interface Message flow
Related Work
Future Work
Conclusion
Solutions
Background
Our Approach
Proxy Service
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
OvervieOverview:w:Motivation
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Solutions
Related Work
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SolutionsSolutions
RobustBPEL (Static Proxies) [11] RobustBPEL-2 (Dynamic Proxies) [10] TRAP/BPEL (Generic Proxies) [9]
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Our Approach
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Original ApplicationOriginal Application
OvervieOverview:w:Motivation
Related Work
Background
Our Approach
Future Work
Conclusion
Solutions
Production
Service
Customer
Accounting
Service
Inventory
Service
Delivery
Service
Sales ServiceSales Service(BPEL Process)
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Static ProxiesStatic ProxiesOvervieOverview:w:Motivation
Related Work
Background
Our Approach Adapt-ReadyAggregate
Web Service
WS1
pt1
WSn
ptn
......
n partner Web services
Absence of Faults
Presence of Faults
Client Program
Legend:Legend:
Service port type (pt) Service dependencyWeb service (WS)
Future Work
Conclusion
Solutions
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Adapt-ReadyAggregate
Web Service
WS1
pt1
WSn
ptn
......
ptj
ptj
ptj
Static
Proxy
WSi1
pti
WSip
pti
......
WSj1
WSjq
......
pti
p equivalent Web services for WSi
q equivalent Web services for WSj
n partner Web services
Absence of Faults
Presence of Faults
Client Program
Legend:Legend:
Service port type (pt) Service dependencyWeb service (WS)
Static ProxiesStatic ProxiesOvervieOverview:w:Motivation
Related Work
Background
Our Approach
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Conclusion
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Dynamic ProxiesDynamic ProxiesOvervieOverview:w:Motivation
Related Work
Background
Our Approach
ptj
Adapt-ReadyAggregate
Web Service
WS1
pt1
WSn
ptn
......
Dynamic
Proxy
pti
registryservice
n partner Web services
Absence of Faults
Presence of Faults
Client Program
Legend:Legend:
Service port type (pt) Service dependencyWeb service (WS)
Future Work
Conclusion
Solutions
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Dynamic ProxiesDynamic ProxiesOvervieOverview:w:Motivation
Related Work
Background
Our Approach
ptj
Adapt-ReadyAggregate
Web Service
WS1
pt1
WSn
ptn
......
Dynamic
Proxy
pti
registryservice
n partner Web services
Absence of Faults
Presence of Faults
Client Program
Legend:Legend:
Service port type (pt) Service dependencyWeb service (WS)
Future Work
Conclusion
Solutions
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Generic ProxiesGeneric Proxies
Why – One proxy for multiple composite services
Promote reuse
– Improved adaptive behavior Avoid failed components Failure must not occur first
– User-specified failure handling Choice Retry Replicate Alternative Check-pointing
– Dynamic Policy modification
OvervieOverview:w:Motivation
Related Work
Background
Our Approach
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Generic Proxies Generic Proxies (2)(2)
OvervieOverview:w:Motivation
Related Work
Background
Our Approach
Service discovery
Client Program Client Program
ptg
Adapt-ReadyAggregate
Web Service 1
Adapt-ReadyAggregate
Web Service K…
Generic
ProxyDeveloped once
to provide
autonomic
behavior.
Recovery Policy
Recovery Policy
Future Work
Conclusion
Solutions
Replicate
Retry
Alternative resource
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
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Related WorkRelated Work Dynamism and Fault-Tolerance in Web service
composition– Messaging layer adaptation
Policy-driven Require purpose built engine AdaptiveBPEL [4], wsBus [6], Charfi [7]
– Application Layer BPEL manually annotated with comments/code Require purpose built engine Baresi [5], BPELJ [8]
Adaptability in scientific Grid Workflow systems– user-defined failure handling– Karajan [1], Kepler [2]
No separation of concerns
– Grid-WFS [3] Workflow annotated with failure handling strategy
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
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Future WorkFuture Work Grid Computing
– Extending Recovery Policy– Very High-level composition tools for scientific grid
applications
Software Adaptation– Languages– Applications
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AgendaAgenda
Motivation Background Our Approach Solutions Related Work Future Work Conclusion
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ConclusionConclusion Acknowledgements
– FIU Dr. Masoud Sadjadi (Advisor) Eduardo Monteiro
– IBM Research
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ConclusionConclusion Questions?OvervieOvervie
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ReferencesReferences1. G. von Laszewski et. al, Java CoG Kit Karajan/GridAnt Workflow Guide,
Technical Report, Argonne National Laboratory, 2005.2. B. Ludäscher et. al, Scientific Workflow Management and the KEPLER System,
Concurrency and Computation: Practice & Experience, Special Issue on Scientific Workflows, 2005.
3. S. Hwang and C. Kesselman, GridWorkflow: A Flexible Failure Handling Framework for the Grid, Proc. 12th IEEE International Symposium on High Performance Distributed Computing, 2004.
4. Erradi et. al. Towards a policy driven framework for adaptive web services composition. In Proceedings of International Conference on Next Generation Web Services Practices, 2005
5. Baresi et. al. Smart monitors for composed services. In ICSOC ’04: Proceedings of the 2nd international conference on Service oriented computing, 2004.
6. Erradi et. al. wsBus: QoS-aware middleware for relaible web services interaction. In IEEE International Conference on e-Technology, e-Commerce and e-Service, 2005
7. Charfi et. al. An aspect based process container for BPEL. In Proceedings of the 1st Workshop on Aspect-Oriented Middleware Development. 2005
8. Blow et. al, Bpelj: BPEL for Java. White Paper.9. Onyeka Ezenwoye and S. Masoud Sadjadi. TRAP/BPEL: A framework for
dynamic adaptation of composite services. (WEBIST 2007)10. Onyeka Ezenwoye and S. Masoud Sadjadi. RobustBPEL2: Transparent
autonomization in business processes through dynamic proxies. (ISADS 2007)11. Onyeka Ezenwoye and S. Masoud Sadjadi. Enabling robustness in existing
BPEL processes. (ICEIS 2006)
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