Yuhui Chen; Romanovsky, A.;IT ProfessionalVolume 10, Issue 3, May-June 2008 Page(s):29 - 35 Digital Object Identifier 10.1109/MITP.2008.49

Improving the Dependability of Web Services Integration

Reporter: 廖宇祥Date: 2009.05.24

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OutlineIntroductionWeb Services DependabilityWS-Mediator ApproachWS-Mediator FrameworkEvaluationConclusion

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IntroductionThis paper propose an approach to improve the

dependability of Web services integration.

Using an off-the-shelf mediator architecture to support resilience-explicit dynamic Web services integration.

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Web ServiceWeb services offer advantages over conventional

distributed computing middleware platforms.

Implement capabilities and functionalities via computer networks, especially the Web.

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Web Service cont.XMLSOAPWSDLUDDI

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Web Services DependabilitySome of those services are dynamically discovered via

UDDI.

Research on the topic typically focuses on ensuring these services’ dependability and the communication between clients and service providers.

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WS-Mediator Approach

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WS-Mediator General Architecture

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The WS-Mediator is an architectural solution deployed on a distributed infrastructure between a set of clients and Web services that they access.

In Web services, the distinction between a client and a service provider is blurry.

WS-Mediator General Architecture

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Dynamic ReconfigurationThe dynamicreconfiguration component is handling

service-execution procedures.

The faulttolerance mechanismsfault-tolerance techniques, which can vary when adapted

to particular application scenarios.

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Service Policies

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When a client invokes the submediator, three kinds of information are assembled in the SOAP messageembedded SOAP messagesan execution policya global-execution policy

Resilience-Explicit Computing

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It’s a critical concept in the WS-Mediator approach.

The resilience metadata generated by the monitoring mechanism is used for resilience-explicit dynamic reconfiguration.

WS-Mediator Framework

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Implemented a Java prototype of the WS-Mediator to validate the approach’s applicability.

Consists of the remote submediator and Mediator-Elite components.

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Evaluation

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deployed a Java WS-Mediator framework on three Blast Web services:EBIVBIDDBJ

Evaluation cont.

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The recovery block execution mode

Evaluation cont.

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the N-version programming execution mode

Conclusion

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The evaluation experiments have demonstrated the potential of our WS-Mediator system.

modeling a detailed overall architecture of the WS-Mediator system and its components.

We envision deploying a general WS-Mediator system for public access and evaluation as well as integrating the WS-Mediator system into a real-world e-Science application.

The End.

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