Time-aware selection approach for service composition based on pruning and improvement techniques
- PDF / 2,814,826 Bytes
- 33 Pages / 439.642 x 666.49 pts Page_size
- 19 Downloads / 158 Views
Time-aware selection approach for service composition based on pruning and improvement techniques Ikbel Guidara1
· Nawal Guermouche2 · Tarak Chaari3 · Mohamed Jmaiel4
© Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract In service-oriented environments, abstract business processes can be implemented by concrete services to build complex applications. Given global user constraints, service selection allows to identify the best combination of services with respect to the business constraints. Generally, the selection problem is challenging, but it is particularly complex when dealing with QoS (quality of service) values, which can change during the time associated with temporal constraints. Indeed, these constraints make the selection problem heavily constrained, which can present a barrier for enabling effective service selection. Unlike static QoS values which have been deeply studied in the existing service selection approaches, time-dependent QoS associated with temporal constraints are insufficiently taken into consideration. Moreover, existing approaches cannot handle heavily constrained problems and usually do not provide strategies to detect the source of failure in order to enhance the selection problem in case there is no solution. In this paper, we introduce a new service selection approach, while considering time-dependent QoS values associated with temporal constraints. First, pruning techniques are proposed. The aim of the pruning process is twofold: (1) it allows for reducing the search space and thus, enhancing the efficiency of the selection process; (2) it allows for improving the selection problem by detecting at earlier stages the possible causes of failure, even before the selection process. Second, based on the pruning phase, improvement techniques are proposed to identify possible actions for finding a solution. Third, an exact and an approximate service selection algorithms under several constraints are given. Finally, we demonstrate the effectiveness of our approach through experimental results. Keywords Service selection · QoS constraints · Temporal constraints · Optimization · Pruning · Time-dependent QoS
1 Introduction In service-oriented environments, several services can be composed to implement complex applications. These latter are usually specified as complex abstract business processes Ikbel Guidara
[email protected]
Extended author information available on the last page of the article.
Software Quality Journal
composed of a set of abstract tasks. To implement business applications, for each abstract task, one concrete service is selected from a set of functionally equivalent services that differ in their QoS values. The allocation of services to business tasks is performed at run time based on the user’s requirement - usually specified in a service-level agreement (SLA) (Guidara et al. 2012). In this context, QoS-based service selection aims at finding the best combination of services that satisfies the end-to-end QoS constraints while f
Data Loading...
