The Internet has become popular and many traditional services have changed into web service stage by stage. The web server with single architecture is no longer satisfying a large number of user requests and the cluster-based web server architecture becomes another suitable solution. Dispatch mechanism play an important role in web server cluster and there are many load balancing policies have been proposed recently. But, these research has only simulation, performance of these policies operate in a real system is unknown. In these simulation all has an assumption that web traffic is heavy-tailed distribution. However, in our experience, the assumption has changed. Web content has become large because network bandwidth increasing and more and more large files like video¡Baudio and tail software, etc. coming in. We defined this web traffic is a data-intensive workload. In this study, we use a real and data-intensive web site to measure and compare these scheduling policies.

Este trabalho apresenta o projeto e a implementação da política de escalonamento com suporte à migração de processos JUMP. A migração de processos é uma ferramenta importante que complementa a alocação inicial realizada pela política de escalonamento em um ambiente paralelo distribuído, permitindo um balanceamento de carga dinâmico e mais refinado, resultando em um melhor desempenho do ambiente e menor tempo de resposta das aplicações paralelas distribuídas. A nova política unifica a alocação inicial e migração de processos em um único algoritmo, de forma a compartilhar decisões para o objetivo comum de prover um melhor desempenho para aplicações de uso intensivo de processamento em clusters heterogêneos. A política é implementada sobre o ambiente de escalonamento flexível e dinâmico AMIGO, adaptado para o suporte à migração de processos. A avaliação de desempenho mostrou que a nova política oferece ganhos expressivos nos tempos de resposta quando comparada às outras duas políticas de escalonamento implementadas no AMIGO, em quase todos os cenários, para diversas aplicações e diversas situações de carga do ambiente / This work presents the project and implementation of the scheduling policy with process migration support JUMP. Process migration is an important tool that complements the initial placement performed by the scheduling policy in a distributed parallel environment, allowing for dynamic and more refined load balancing, resulting in better performance of the environment and shorter response time for distributed parallel applications. The new policy unifies initial placement and process migration in a single algorithm, enabling the sharing of decisions for the common goal of providing a better performance for CPU-bound applications in heterogeneous clusters. The policy is implemented over the dynamical and flexible environment AMIGO, adapted in order to support process migration. Performance evaluation showed that the new policy offers expressive gains in response times when compared to other two scheduling policies implemented in AMIGO in almost all scenarios, for different applications and different environment load situations

Este trabalho apresenta o projeto e a implementação da política de escalonamento com suporte à migração de processos JUMP. A migração de processos é uma ferramenta importante que complementa a alocação inicial realizada pela política de escalonamento em um ambiente paralelo distribuído, permitindo um balanceamento de carga dinâmico e mais refinado, resultando em um melhor desempenho do ambiente e menor tempo de resposta das aplicações paralelas distribuídas. A nova política unifica a alocação inicial e migração de processos em um único algoritmo, de forma a compartilhar decisões para o objetivo comum de prover um melhor desempenho para aplicações de uso intensivo de processamento em clusters heterogêneos. A política é implementada sobre o ambiente de escalonamento flexível e dinâmico AMIGO, adaptado para o suporte à migração de processos. A avaliação de desempenho mostrou que a nova política oferece ganhos expressivos nos tempos de resposta quando comparada às outras duas políticas de escalonamento implementadas no AMIGO, em quase todos os cenários, para diversas aplicações e diversas situações de carga do ambiente / This work presents the project and implementation of the scheduling policy with process migration support JUMP. Process migration is an important tool that complements the initial placement performed by the scheduling policy in a distributed parallel environment, allowing for dynamic and more refined load balancing, resulting in better performance of the environment and shorter response time for distributed parallel applications. The new policy unifies initial placement and process migration in a single algorithm, enabling the sharing of decisions for the common goal of providing a better performance for CPU-bound applications in heterogeneous clusters. The policy is implemented over the dynamical and flexible environment AMIGO, adapted in order to support process migration. Performance evaluation showed that the new policy offers expressive gains in response times when compared to other two scheduling policies implemented in AMIGO in almost all scenarios, for different applications and different environment load situations

OGrid Anywhere é um middleware de grade computacional ponto-aponto (P2P), capaz de agrupar em uma organização virtual ou federação qualquer equipamento dotado de recursos computacionais, inclusive receptores digitais. O objetivo deste projeto de mestrado apresentado nesta monografia é desenvolver e avaliar algoritmos de escalonamento que possibilitem uma distribuição adequada de processos nos elementos da grade computacional proposta pelo Grid Anywhere. Foram realizados experimentos utilizando o simulador GridSim, simulando um ambiente definido por esse middleware. Por meio dessa junção entre Grades Computacionais e TV Digital, pretende-se promover a inclusão digital permitindo que recursos computacionais sejam compartilhados de maneira a possibilitar que usuários com receptores limitados executem aplicações que demandem mais recursos que aqueles ofertados pelo hardware / GRid Anywhere is a middleware for grid computing peer-to-peer (P2P), capable of bringing together into a virtual organization or federation any equipment having computing resources, including digital receivers. The objective of this masters project presented in this monograph is to develop and evaluate scheduling algorithms that allow an adequate distribution of applications in computational grid elements proposed by the Grid Anywhere. Experiments were carried out using the GridSim simulator, simulating an environment defined by the middleware. Through this joint between Grid Computing and Digital TV, it is possible to promote digital inclusion by allowing computing resources to be shared, so as to enable users with limited receivers to run applications that require more resources than those offered by the hardware

OGrid Anywhere é um middleware de grade computacional ponto-aponto (P2P), capaz de agrupar em uma organização virtual ou federação qualquer equipamento dotado de recursos computacionais, inclusive receptores digitais. O objetivo deste projeto de mestrado apresentado nesta monografia é desenvolver e avaliar algoritmos de escalonamento que possibilitem uma distribuição adequada de processos nos elementos da grade computacional proposta pelo Grid Anywhere. Foram realizados experimentos utilizando o simulador GridSim, simulando um ambiente definido por esse middleware. Por meio dessa junção entre Grades Computacionais e TV Digital, pretende-se promover a inclusão digital permitindo que recursos computacionais sejam compartilhados de maneira a possibilitar que usuários com receptores limitados executem aplicações que demandem mais recursos que aqueles ofertados pelo hardware / GRid Anywhere is a middleware for grid computing peer-to-peer (P2P), capable of bringing together into a virtual organization or federation any equipment having computing resources, including digital receivers. The objective of this masters project presented in this monograph is to develop and evaluate scheduling algorithms that allow an adequate distribution of applications in computational grid elements proposed by the Grid Anywhere. Experiments were carried out using the GridSim simulator, simulating an environment defined by the middleware. Through this joint between Grid Computing and Digital TV, it is possible to promote digital inclusion by allowing computing resources to be shared, so as to enable users with limited receivers to run applications that require more resources than those offered by the hardware

L'étude des Systèmes Contrôlés en Réseaux (SCR) repose sur l'identification des exigences de fonctionnement de l'application appelées Qualité de Contrôle (QdC) et sur l'évaluation de la Qualité de Service (QdS) offerte par le réseau. Les travaux sur les SCR se repartissent selon deux approches : la commande en réseau et la commande de réseau. Cette thèse se positionne sur la deuxième approche avec une recherche axée sur la modélisation des mécanismes d'ordonnancement implémentés dans les équipements réseau et notamment dans les commutateurs Ethernet qui sont de plus en plus utilisés dans les applications industrielles. Ce travail de recherche étudie plus particulièrement comme paramètre de QdS, les délais qui engendrent des perturbations sur le système commandé. Cette thèse propose deux modèles de classification de service reposant sur des ordonnanceurs WRR (Weighted Round Robin). La première modélisation suit une approche constructive en utilisant la théorie du calcul réseau. La seconde s'appuie sur une phase d'identification à partir de simulations numériques et de la logique floue. Dans les deux cas, le but est d'offrir une bande passante suffisante pour le trafic contraint temporellement tout en maximisant la bande passante dédiée aux autres trafics pour éviter des effets famine. L'approche calcul réseau permet de configurer le réseau hors-ligne pour répondre à des contraintes temporelles strictes du SCR. La solution basée sur la logique floue autorise une commande dynamique de l'ordonnanceur pour ajuster en ligne le réseau en fonction des variations du trafic. Elle ne peut s'appliquer qu'à des SCR ayant des contraintes de temps souples / The study of the Networked Control Systems (NCS) is based both on the identification of the application functioning requirements called Quality of Control (QoC) and on the evaluation of the Quality of Service (QoS) offered by the network. The studies on the NCS are classified according to two approaches: the control over network and the control of network. This thesis addresses the second approach and models the scheduling mechanisms implemented in the Ethernet switches that are more and more used in the industrial applications. The specific QoS parameter studied in this thesis is the delay disturbing the controlled system. This thesis proposes two models of classification of service based on WRR (Weighted Round Robin) schedulers. The first modeling follows a constructive approach by using the network calculus theory. The second is based on an identification step from numerical simulations and from the fuzzy logic. In the two cases, the purpose is both to offer enough bandwidth for the time constrained traffic and to maximize the bandwidth dedicated to the others traffics to avoid famine effects. The network calculus approach is used to configure off-line the network in respecting the NCS strict time constraints. The solution based on the fuzzy logic enables a dynamic control of the scheduler in order to tune on-line the network according to the traffic variations. This latter can be applied only to NCS with soft time constraints

In mobile and wireless networks, data broadcasting for popular data items enables the efficient utilization of the limited wireless bandwidth. However, efficient data scheduling schemes are needed to fully exploit the benefits of data broadcasting. Towards this goal, several broadcast scheduling policies have been proposed. These existing schemes have mostly focused on either minimizing response time, or drop rate, when requests are associated with hard deadlines. The inherent inaccuracy of hard deadlines in a dynamic mobile environment motivated us to use Service Level Agreements (SLAs) where a user specifies the utility of data as a function of its arrival time. Moreover, SLAs provide the mobile user with an already familiar quality of service specification from wired environments. Hence, in this dissertation, we propose SAAB, an SLA-aware adaptive data broadcast scheduling policy for maximizing the system utility under SLA-based performance measures. To achieve this goal, SAAB considers both the characteristics of disseminated data objects as well as the SLAs associated with them. Additionally, SAAB automatically adjusts to the system workload conditions which enables it to constantly outperform existing broadcast scheduling policies.

In mobile and wireless networks, data broadcasting for popular data items enables the efficient utilization of the limited wireless bandwidth. However, efficient data scheduling schemes are needed to fully exploit the benefits of data broadcasting. Towards this goal, several broadcast scheduling policies have been proposed. These existing schemes have mostly focused on either minimizing response time, or drop rate, when requests are associated with hard deadlines. The inherent inaccuracy of hard deadlines in a dynamic mobile environment motivated us to use Service Level Agreements (SLAs) where a user specifies the utility of data as a function of its arrival time. Moreover, SLAs provide the mobile user with an already familiar quality of service specification from wired environments. Hence, in this dissertation, we propose SAAB, an SLA-aware adaptive data broadcast scheduling policy for maximizing the system utility under SLA-based performance measures. To achieve this goal, SAAB considers both the characteristics of disseminated data objects as well as the SLAs associated with them. Additionally, SAAB automatically adjusts to the system workload conditions which enables it to constantly outperform existing broadcast scheduling policies.

Cette thèse s'intéresse aux stratégies de transmission de contenu multimédia des réseaux sans fil. L'intérêt d'une stratégie repose sur sa capacité à gérer les ressources selon les objectifs des applications visées. On propose ainsi un schéma de transmission, qui garantit la qualité de service (QdS), quelles que soient les conditions du canal et suivant les spécificités du contenu multimédia. On exploite pour cela les diversités (spatiales, fréquentielles, etc.) du canal radio. A ce titre, l'association MIMO-OFDM apparaît comme une solution idéale pour accroitre les performances du système. On propose ainsi un système MIMO-OFDMA, qui intègre des stratégies inter-couches. Celles-ci se basent sur des techniques d'adaptation de lien pour régler dynamiquement les paramètres du système. On développe en premier un schéma inter-couches PHY 1 APPL, associé à un système MIMO-OFDM mono-utilisateur, qui transmet une vidéo H.264/SVC. L'adaptation de lien permet de définir le jeu de paramètres optimaux, qui minimise la distorsion de la vidéo reçue. On introduit ainsi une politique d'optimisation sous contraintes de puissance et de taux d'erreurs binaires. Pour tenir compte d'aspects de transmission réalistes, on propose un schéma inter-couches PHY/MAC, dédié à un système MIMO-OFDMA, multi-utilisateurs et multi-services. Ce dernier associe un algorithme d'ordonnancement, au paramétrage optimal, pour fournir au maximum d'utilisateurs des débits utiles respectant les exigences des services demandés. Enfin, on combine les deux premières solutions pour définir les paramètres optimaux minimisant la distorsion de la vidéo reçue par utilisateur, tout en garantissant la QdS des autres services. / This thesis focuses on the transmission strategies of the multimedia content in wireless networks. The advantage of a such strategy is its ability to manage the resources, according to the objectives of the targeted applications. We propose a transmission scheme, which guarantees the quality of service (QoS), depending on the channel state information and on the multimedia content specifications. We take advantage of the radio channel diversities (spatial, frequency, etc.). ln fact, the association of MIMO and OFDM techniques appears as effective solution to increase the system performance. For this reason, we propose a MIMO-OFDMA system, which considers cross-layer srtategies based on link adaptation schemes to dynamically adjust the system parameters. Firstly, we develop a PHY/APPL cross-layer strategy, dedicated to a single user of a MIMO-OFDMA system, which transmits an H.264/SVC video. The Iink adaptation scheme allows to define the optimum parameters, which minimize the end-ta-end video distortion by using an optimization algorithm under power and bit error rate constraints. To consider the realistic transmission aspects, we propose a PHY/MAC cross-layer strategy, dedicated to a multi-user, multi-service, MIMOOFDMA system. This scheme combines a scheduling policy with optimal parameterization to provide a satisfied troughput to a maximum number of users, acheiving the required services. Finally, the first two solutions are combined to determine the optimal parameters which minimize the end-ta-end distortion of the received video by user, and also acheive QoS requirements of the other services.