Automata for Web Services Fault Monitoring and Diagnosis

Like any software, web service fault management is also required to go through different phases of fault management lifecycle. Model based diagnosis has been a well established practice for its several positive aspects including cognitively being better understood by development and testing teams. Automata is a simple and formally well defined model being used for monitoring and diagnosis of system faults. For the reason, here we have reviewed works on automata for web service fault management and also propose a model of stochastic automata for the purpose

Automated synthesis of local time requirement for service composition

National Research Foundation (NRF) Singapore ANR-NRF French-Singaporean research program ProMi

Adaptive Service Composition Based on Runtime Verification of Formal Properties

Service-Oriented Computing (SOC) has been used in business environments in order to integrate heterogeneous systems. The dynamic nature of these environments causes \ changes in the application requirements. As a result, service composition must be flexible, dynamic and adaptive, which motivate the need to ensure the service composition behavior \ at runtime. The development of adaptive service compositions is still an opportunity due to the complexity of dealing with adaptation issues, for example, how to provide runtime verification \ and automatic adaptation. Formal description techniques can be used to detect runtime undesirable behaviors that help in adaptation process. However, formal techniques have been \ used only at design-time. In this paper, we propose an adaptive service composition approach based on the lightweight use of formal methods. The aim is detecting undesirable behaviors in \ the execution trace. Once an undesirable behavior is detected during the execution of a service composition, our approach triggers an adequate reconfiguration plan for the problem at \ runtime. In order to evaluate the effectiveness of the proposal, we illustrate it with a running example

Correctness of services and their composition

We study correctness of services and their composition and investigate how the design of correct service compositions can be systematically supported. We thereby focus on the communication protocol of the service and approach these questions using formal methods and make contributions to three scenarios of SOC.Wir studieren die Korrektheit von Services und Servicekompositionen und untersuchen, wie der Entwurf von korrekten Servicekompositionen systematisch unterstützt werden kann. Wir legen dabei den Fokus auf das Kommunikationsprotokoll der Services. Mithilfe von formalen Methoden tragen wir zu drei Szenarien von SOC bei

Correctness of services and their composition

We study correctness of services and their composition and investigate how the design of correct service compositions can be systematically supported. We thereby focus on the communication protocol of the service and approach these questions using formal methods and make contributions to three scenarios of SOC.Wir studieren die Korrektheit von Services und Servicekompositionen und untersuchen, wie der Entwurf von korrekten Servicekompositionen systematisch unterstützt werden kann. Wir legen dabei den Fokus auf das Kommunikationsprotokoll der Services. Mithilfe von formalen Methoden tragen wir zu drei Szenarien von SOC bei

Model-Based Availability Evaluation of Composed Web Services, Journal of Telecommunications and Information Technology, 2014, nr 4

Web services composition is an emerging software development paradigm for the implementation of distributed computing systems, the impact of which is very relevant both in research and industry. When a complex functionality has to be delivered on the Internet, a service integrator can produce added value by delivering more abstract and complex services obtained by composition of existing ones. But while isolated services availability can be improved by tuning and reconguring their hosting servers, with Composed Web Services (CWS) basic services must be taken as they are. In this case, it is necessary to evaluate the composition effects. The authors propose a high-level analysis methodology, supported by a tool, based on the transformation of BPEL descriptions of CWS into models based on the fault tree availability evaluation formalism that enables a modeler, unfamiliar with the underlying combinatorial probabilistic mathematics, to evaluate the availability of CWS, given components availability and expected execution behavior