QoS-Aware Real-Time Composition Algorithms for Service-Based Applications
QoS-Aware Real-Time Composition Algorithms for Service-Based Applications
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DOI：
10.1109/tii.2009.2026422
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发表时间：
2009-07
影响因子：
12.3
通讯作者：
I. Estévez-Ayres;P. Basanta-Val;M. García-Valls;Jesús Arias-Fisteus;L. Almeida
中科院分区：
文献类型：
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作者：
I. Estévez-Ayres;P. Basanta-Val;M. García-Valls;Jesús Arias-Fisteus;L. Almeida
本文提出了一种在具有实时性和容错要求的分布式系统中具有服务质量（QoS）感知的服务组合模型。该模型可应用于诸如远程监测、控制和监视等应用领域。经典的实时系统方法无法提供在需要将高度动态性与时间可预测性相结合的新兴环境中所需的灵活性和容错能力。我们的方法通过结合面向服务范式和分布式实时系统的概念来应对这些新挑战。我们提出了一个基于整体的基于时间触发的设计和配置方法的具体系统模型。基于该模型，我们针对具有时间要求的具有QoS感知的基于服务的应用的组合提出了两种算法：一种是穷举算法，它根据品质因数计算出最优的服务组合，适用于离线组合；另一种是基于启发式和部分品质因数的改进算法，适用于在线组合。实验结果表明，后者极大地减少了所探索的组合数量，同时解决方案质量的下降极小，使其在动态环境中可用于在线执行。
This paper presents a model for quality-of-service (QoS)-aware service composition in distributed systems with real-time and fault-tolerance requirements. This model can be applied in application domains like, for example, remote monitoring, control and surveillance. Classic approaches to real-time systems do not provide the flexibility and fault-tolerance required in new emerging environments that need to combine a high degree of dynamism with temporal predictability. Our approach addresses these new challenges by combining concepts from the service oriented paradigm and distributed real-time systems. We propose a concrete system model based on a holistic time-triggered-based approach for design and configuration. Based on this model, we propose two algorithms for the composition of QoS-aware service-based applications with temporal requirements: an exhaustive algorithm that computes the optimal service combination in terms of a figure of merit, suitable for offline composition; and an improved algorithm based on heuristics and partial figures of merit, suitable for online composition. Experimental results show that the latter reduces dramatically the number of combinations explored with a minimal degradation in the quality of the solution, making it feasible for online execution in dynamic environments.