@article {Kareliotis2009284,
	title = {IQoS-aware exception resolution for BPEL processes: A middleware-based framework and performance evaluation},
	journal = {International Journal of Web and Grid Services},
	volume = {5},
	number = {3},
	year = {2009},
	note = {cited By (since 1996) 0},
	pages = {284-320},
	abstract = {Web Services Business Process Execution Language (WS-BPEL) is widely used nowadays for specifying and executing composite business processes. During the execution, however, of such business processes, a number of faults stemming from the nature of SOA may occur. The WS-BPEL scenario designer must therefore use the provisions offered by WS-BPEL to catch these exceptions and resolve them. The system fault handler specification, however, is an additional task for the WS scenario designer, while the presence of such handlers within the scenario necessitates extra maintenance activities. In this paper, we propose a middleware-based framework for system exception resolution, which undertakes the tasks of failure interception, discovery of alternative services and their invocation. The process of selecting the alternative services can be driven by process consumer-specified Quality of Service (QoS) policy. Moreover, the middleware arranges for bridging syntactic differences between the originally invoked services and functionally equivalent replacements to it, by employing XSLT-based transformations. The middleware is deployed and maintained independently of the WS-BPEL scenarios, thus removing the need for specifying and maintaining system fault handlers within the scenarios. We also present performance measures, establishing that the overhead imposed by the addition of the proposed middleware layer is minimal. Copyright Β{\textcopyright} 2009, Inderscience Publishers.},
	keywords = {Ad hoc networks, BPEL process, Exception handling, Exception resolution, Middleware, Performance metrics, QoS, Quality control, Quality of service, Scalability, Telecommunication services, Web services},
	doi = {10.1504/IJWGS.2009.028346},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70349462474\&partnerID=40\&md5=4511b42fde076617cd6ac0139e3f588d},
	author = {Christos Kareliotis and Costas Vassilakis and S. Rouvas and P. Georgiadis}
}
@conference {Christos2009271,
	title = {QoS-driven adaptation of BPEL scenario execution},
	booktitle = {2009 IEEE International Conference on Web Services, ICWS 2009},
	year = {2009},
	note = {cited By (since 1996) 0},
	month = {7},
	pages = {271-278},
	abstract = {BPEL/WSBPEL is the predominant approach for combining individual web services into integrated business processes, allowing for the specification of their sequence, control flow and data exchanges. BPEL however does not include mechanisms for considering the invoked services{\textquoteright} Quality of Service (QoS) parameters and thus BPEL scenarios can neither tailor their execution to the individual user{\textquoteright}s needs or adapt to the highly dynamic environment of the WEB, where new services may be deployed, old ones withdrawn or existing ones changing their QoS parameters. Moreover, infrastructure failures in the distributed environment of the web introduce an additional source of failures that must be considered in the context of QoS-aware service execution. In this work we propose a framework for addressing the issues identified above; the framework allows the users to specify the QoS parameters that they require and it undertakes the task of locating and invoking suitable services. Finally, the proposed framework intercepts and resolves faults occurring during service invocation, respecting the QoS restrictions specified by the consumer. Β{\textcopyright} 2009 IEEE.},
	keywords = {Adaptive execution, BPEL, Control flows, Data exchange, Distributed environments, Dynamic environments, Infrastructure failures, Integrated business, New services, Performance evaliation, QoS parameters, Quality of service, Quality of Service parameters, Service execution, Service invocation, Web services},
	doi = {10.1109/ICWS.2009.80},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70449472686\&partnerID=40\&md5=5303ebeff04a4e7a062f77209521d561},
	author = {Christos Kareliotis and Costas Vassilakis and S. Rouvas and P. Georgiadis}
}
@conference {Christos2008248,
	title = {Exception resolution for BPEL processes: A middleware-based framework and performance evaluation},
	booktitle = {Proceedings of the 10th International Conference on Information Integration and Web-based Applications and Services, iiWAS 2008},
	year = {2008},
	note = {cited By (since 1996) 0},
	month = {12},
	pages = {248-256},
	abstract = {WS-BPEL is widely used nowadays for specifying and executing composite business processes within the Service Oriented Architecture (SOA). During the execution however, of such business processes, a number of faults stemming from the nature of SOA (e.g. network or server failures) may occur. The WS-BPEL scenario designer must therefore use the provisions offered by WS-BPEL to catch these exceptions and resolve them, usually by invoking some equivalent web service that is expected to be reachable and available. System fault handler specification is though an additional task for the WS scenario designer, while the presence of such handlers within the scenario necessitates extra maintenance activities, as new alternate services emerge or some of the specified ones are withdrawn. In this paper, we propose a middleware-based framework for system exception resolution, which undertakes the tasks of failure interception, discovery of alternate services and their invocation. The middleware is deployed and maintained independently of the WS-BPEL scenarios, removing thus the need for specifying and maintaining system fault handlers within the scenarios. We also present performance measures, establishing that the overhead imposed by the addition of the proposed middleware layer is minimal. Β{\textcopyright} 2008 ACM.},
	keywords = {Ad hoc networks, Business Process, Exception handling, Information retrieval, Information services, Maintenance activity, Middleware, Middleware layer, Performance evaluation, Performance measure, Performance metrics, Quality control, Quality of service, Quality of service (QoS), Scalability, Service oriented architecture (SOA), System faults, Telecommunication services, Web services, WS-BPEL},
	doi = {10.1145/1497308.1497355},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70349146138\&partnerID=40\&md5=9a5231fe52fffef11707efd4f3489a37},
	author = {Christos Kareliotis and Costas Vassilakis and S. Rouvas and P. Georgiadis}
}
