Special Issue: Performance Evaluation of Communications in Distributed Systems and Web‐Based Service Architectures

Abstract

This special issue is devoted to performance evaluation of communications in distributed systems and Web-based service architectures. Performance evaluation is still a topic that attains a lot of attention in both distributed and mobile systems as well as Web-based service architectures. Owing to the recent advances in internet-based applications as well as distributed and mobile communication systems, we are witnessing a variety of new technologies. However, these systems are becoming very large and complex at the same time. Several challenges remain to be resolved before these systems become a commodity. Guaranteeing Quality of Service (QoS) and provisioning of web-based systems as well as distributed and mobile systems and evaluating their communication performance are among the challenging problems in the design of these systems. Quantitative analysis can be very difficult and may be intractable because of the state space explosion. New methods and tools have recently emerged for these kinds of complex systems, such as Stochastic Automata Networks, Stochastic bounds, PEPA, to mention just a few. This special issue covers the recent studies on the performance evaluation of communications in distributed systems and Web-based service architectures. The Call-For-Papers has attracted a large number of excellent paper submissions. All papers have been reviewed by at least three reviewers, and in some instances four reviewers. However, due to space limitations, we could only accept eight papers dealing with distributed, mobile systems and web-based architecture design using both analytical methods and simulation studies to evaluate their performance. We hope you will find the set of papers interesting as much as we do. The paper by R. Ben Halima et al. proposes a monitoring and measurement framework associated with a real Web services-based application and the resulting experimental data of a large-scale deployment and measurement campaign. The next paper by H. Xie et al. proposes a formalized approach for designing a P2P-based dynamic load balancing scheme. The paper by N. Dessart et al. focuses on how to detect anomalies in a distributed manner by using wireless sensor networks by considering medical context. They propose a distributed algorithm that allows raising alarms under some initial rules to alert efficiently medical staff in case of critical situations. The paper by B. Yahya et al. presents a new MAC layer protocol for wireless sensor networks that reduces energy consumption and provides QoS guarantees through the use of service differentiation concept. The proposed EQ-MAC protocol consists of two sub-protocols: Classifier MAC (C-MAC) and Channel Access MAC (CA-MAC). The CA-MAC is an energy efficient medium access mechanism that uses a hybrid approach of both scheduled and unscheduled schemes to gain a save in energy, and hence prolonging the network's lifetime. The paper by D. Cavendish et al. presents a methodology based on MVA to analyze transactions on a distributed multi-server system. The main idea is to provide conservative bounds on the results by MVA taking into account the variance of the processes. The paper by J. M. Fourneau et al. proposes upper and lower models that provide bounds on response times for Web service architectures. The bounded models are obtained by simplification processes which are associated with stochastic comparisons of random variables. Thus the simplified models are stochastic bounds for the original ones. They prove using stochastic comparisons that the response times computed on the bounding models are really upper and lower bounds on the considered models. The paper by M. Escheikh et al. proposes to use a mathematical model to evaluate the performance of a 802.11 MAC layer based on non Markovian Stochastic Petri Nets formalism (NMSPN). They propose two MAC IEEE 802.11e models by considering service differentiation features. The last paper by M. Zhang et al. proposes an efficient scheduling and load balancing scheme for dynamic P2P-based system. Experimental results show that significant gain can be obtained when compared to previous load balancing strategies.