Deploying virtual network functions (VNFs) such as WAN accelerators, network address translators (NATs) and 5G functions at the network edge (NE) can significantly reduce the experienced latency of delay-ultrasensitive applications (e.g., autonomous vehicles and Internet of things). Nonetheless, a major challenge to their anticipated large-scale deployment is the ability to efficiently allocate and manage the scarce NE resources hosting these functions. In this thesis, we describe a novel containerized infrastructure manager (cIM) that extends current managers, such as Kubernetes, with the necessary building blocks to provide an accurate yet elastic resource allocation service to containerized VNFs at scale. The proposed cIM treats the main modules of the VNFs, i.e., the containerized VNF components (cNFCs), as atomic special-purpose functions that can be rapidly deployed to form complex network services. The main component of the proposed cIM, the resource reservation manager (RRM), employs concepts of risk pooling in the insurance industry to accurately reserve the needed resources for the hosting containers. More precisely, to meet anticipated cNFCs demand fluctuation, the RRM accurately reserves a quota of additional resources that are shared by the containerized functions collected together in clusters. The reserved quota of resources ensures the desired availability level of the cNFCs without over-provisioning the scarce resources of the NE. The RRM considers three different situations namely that of a cNFC instance, a cluster of cNFCs or multiple cNFC clusters sharing the reserved resources. Different allocation approaches are then presented for each of these three situations. Simulation experiments are conducted to evaluate the performance of our reservation schemes from different aspects. The corresponding experimental results demonstrate that our proposed cIM can significantly improve the performance of the cNFCs and guarantee their desired availability with minimal resource reservation. Optimal allocation solutions of the resource pools are further proposed considering the desired availability level and the limit of resource pools. The evaluation results demonstrate that our optimization models and solutions obtain the best performance of relevant testing parameters, e.g., availability.

[pt] A forma como a Computação é realizada está mudando devido à grande capacidade de processamento, armazenamento e comunicação que equipamentos computacionais apresentam atualmente. Cenários de compartilhamento de recursos, onde um único servidor físico é compartilhado entre diferentes aplicações, muitas vezes hospedadas em diversos domínios virtuais, têm se tornado comuns, mas demandam esforços para que o isolamento de desempenho de cada aplicação seja garantido como se ela fosse a única a ser localmente executada. Baseado nesse fato, o objetivo deste trabalho consiste em investigar técnicas para a provisão de reservas de recursos, garantindo, consequentemente, qualidade de serviço (QoS) e isolamento de desempenho às aplicações. A fim de atender ambientes onde o uso de extensões de sistemas operacionais ou o uso de virtualização são indevidos ou inapropriados, a investigação contempla o estudo da viabilidade e efetividade de reservas realizadas no nível do usuário, ou seja, sem que instrumentações no núcleo do sistema operacional sejam necessárias. Para isso, implementamos uma ferramenta capaz de limitar e garantir o uso dos recursos de processamento e disco, utilizando somente primitivas providas pelo Sistema Operacional Linux. Entre outras funcionalidades, essa ferramenta apresenta facilidades para a extensão das políticas de escalonamento, o que atribui a ela flexibilidade na forma como os recursos são compartilhados entre os processos. Com a análise de uso da ferramenta, foi possível identificar as vantagens e limitações das técnicas de gerenciamento utilizadas. Como um estudo de caso da ferramenta implementada, parametrizamos reservas para uma aplicação de três camadas com metas de desempenho e verificamos que, mesmo para aplicações complexas, métodos simples tais como a regressão linear são capazes de predizer o uso de recursos com uma baixa margem de erro. / [en] The way computing is done today is changing as a result of the everincreasing processing, storage, and communication capacities of modern computer hardware. Resource sharing scenarios, in which a physical server is shared for different applications, are becoming much more common. These scenarios require special attention to guarantee that the performance isolation of each application is carried out exactly as if it were being locally executed. Based on this situation, the present work aims at investigating techniques for providing resource reservations and thus guaranteeing quality of service (QoS) and performance isolation for applications. Considering environments in which the use of operating system extensions or the use of virtualization are unreasonable or inappropriate, this work investigates the viability and effectiveness of reservations done at user level, that is, reservations guaranteed with no operating system kernel instrumentation. For this purpose, we have implemented a tool that limits and ensures the proper usage of processing and disk bandwidth resources through the exclusive use of Linux Operating System primitives, which, among other functions, permits easy scheduling policy extensions. This feature enables flexibility in how resources are shared among distinct processes. Through tool usage analysis, we have identified the advantages and limitations of the techniques used. For a case study, aiming to achieve some specific performance goals, we have established parameter reservations for a three-tier application. We were able to verify that, even for complex applications, simple methodologies like linear regressions are capable of predicting resource usage with a low margin of error.

Edge computing is a distributed computing paradigm where computing resources are located physically closer to the data source compared to the traditional cloud computing paradigm. Edge computing enables computation offloading from resource-constrained devices to more powerful servers in the edge and cloud. To offer edge and cloud support to real-time industrial applications, the communication to the servers and the server-side computation needs to be predictable. However, the predictability of offloading cannot be guaranteed in an environment where multiple devices are competing for the same edge and cloud resources due to potential server-side scheduling conflicts. To the best or our knowledge, no offloading scheme has been proposed that provides a highly predictable real-time task scheduling in the face of multiple devices offloading to a set of heterogeneous edge/cloud servers. Hence, this thesis approaches the problem of predictable offloading in real-time environments by proposing a centralized server time reservation system to schedule the offloading of real-time tasks to edge and cloud servers. Our reservation system allows end-devices to request external execution time in advance for real-time tasks that will be generated in the future, therefore when such a task is created, it already has a designated offloading server that guarantees its timely execution. Furthermore, this centralized reservation system is capable of optimizing the reservation scheduling strategy with the goal of minimizing energy consumption of edge servers while meeting the stringent deadline constraints of real-time applications. / Edge computing är ett distribuerat datorparadigm där datorresurser är fysiskt placerade närmare datakällan jämfört med det traditionella molnberäkningsparadigmet. Edge computing möjliggör beräkningsavlastning från resursbegränsade enheter till mer kraftfulla servrar i kanten och molnet. För att erbjuda kant- och molnstöd till industriella tillämpningar i realtid måste kommunikationen till servrarna och beräkningen på serversidan vara förutsägbar. Förutsägbarheten av avlastning kan dock inte garanteras i en miljö där flera enheter konkurrerar om samma kant- och molnresurser på grund av potentiella schemaläggningskonflikter på serversidan. Så vitt vi vet har inget avlastningsschema föreslagits som ger en mycket förutsägbar uppgiftsschemaläggning i realtid inför flera enheter som laddas av till en uppsättning heterogena edge-/molnservrar. Därför närmar sig denna avhandling problemet med förutsägbar avlastning i realtidsmiljöer genom att föreslå ett centraliserat servertidsreservationssystem för att schemalägga avlastningen av realtidsuppgifter till edge- och molnservrar. Vårt reservationssystem tillåter slutenheter att begära extern exekveringstid i förväg för realtidsuppgifter som kommer att genereras i framtiden, därför när en sådan uppgift skapas har den redan en utsedd avlastningsserver som garanterar att den utförs i tid. Dessutom kan detta centraliserade bokningssystem optimera bokningsschemaläggningsstrategin med målet att minimera energiförbrukningen för edge-servrar samtidigt som de stränga deadline-begränsningarna för realtidsapplikationer uppfylls.

No description available.

[pt] Esta tese apresenta novos algoritmos para controle de admissão de usuários em redes móveis celulares. É utilizada a técnica de reserva de recursos, também conhecida por uso de canais de guarda, para atingir os graus de qualidade de serviço desejados para cada tipo de usuário. São propostos algoritmos dinâmicos, capazes de se adaptar ao perfil de tráfego presente na rede e que possuem diferentes filosofias de projeto. Inicialmente, foi considerado o caso de uma classe que resulta em dois tipos de usuários: chamadas novas e chamadas em handoff. Os algoritmos propostos são testados em condições de tráfego representadas por diversas distribuições para o tempo de permanência do usuário na célula. Foi desenvolvido um novo simulador em linguagem C que é capaz de verificar o desempenho dos algoritmos propostos. Resultados analíticos para desempenho dos algoritmos de uma classe e um número fixo de recursos reservados são apresentados empregando uma modelagem por Cadeia de Markov. Foi desenvolvido um método que permite calcular a intensidade de tráfego máxima a qual o sistema pode ser submetido, e a quantidade de recursos a ser reservada assumindo que o objetivo é maximizar a utilização do sistema atendendo os valores de qualidade de serviço estabelecidos, no caso de tempo de retenção do recurso de rádio modelado por uma chamada com distribuição exponencial. Foi proposto um algoritmo simples, dinâmico e distribuído, baseado em medidas em tempo real, cuja meta é acompanhar a curva ótima de número de recursos reservados. Posteriormente, os resultados analíticos empregando Cadeia de Markov são generalizados para M classes. Alguns dos algoritmos definidos para o caso de uma classe são estendidos para o caso de duas classes e seu desempenho é avaliado, utilizando o simulador desenvolvido neste trabalho. O método para calcular a intensidade máxima de recursos que o sistema comporta, sem violar os requisitos de qualidade de serviço, é estendido para o caso de duas classes. Finalmente, são definidos parâmetros que permitem comparar o desempenho dos algoritmos com 2M classes, considerando uma distribuição genérica para o tempo de permanência do usuário na célula. / [en] This thesis presents new algorithms for Channel Admission Control in wireless communications systems. We investigate techniques based in resource reservation, also known as guard channel, to achieve the quality of service desired for each class of users. We propose dynamic schemes based in the cell traffic. Each algorithm has a different goal, some try to minimize the probability of handoff fail, others try to maximize the traffic intensity when the limit imposed by QoS is being approached. First, we considered one class (M = 1) divided in two classes: new users and handoff users. In order to test the new schemes we developed a simulator in C that uses different distributions for the dwell-time. During the simulation, the measures of channel solicitations and the result of their allocation are used to decide whether new calls will be admitted. We also obtained analytic results using a Markov Chain model. We developed a method to calculate the maximum traffic intensity that the system supports without violating the established quality of service constraints, assuming one class of users and the dwell-time modelled by a exponential distribution. This method allows to identify the maximum traffic intensity supported by the system and also the exact number of resources to be reserved for each value of traffic intensity. We proposed a new, dynamic and distributed algorithm based on real time measures which targets to follow the optimum number of reserved curve obtained from our procedure. We generalized the analytic results using M-dimensional Markov Chains to 2M classes of users. Some of the algorithms defined to two classes (M = 1) were extended to the case of four classes (M = 2) and their performances are evaluated using the simulator developed in this work. The method to evaluate the maximum intensity of traffic within the limits of QoS is also extended to the case of four classes. Finally we define new parameters that allow the performance comparison among 2M class algorithms, considering any dwell- time distribution.

Aujourd'hui, les systèmes logiciels sont omniprésents. Parfois, les applications doivent fonctionner sur des dispositifs à ressources limitées. Toutefois, les applications nécessitent un support d'exécution pour faire face à de telles limitations. Cette thèse aborde le problème de la programmation pour créer des systèmes "conscient des ressources" supporté par des environnements d'exécution adaptés (MRTEs). En particulier, cette thèse vise à offrir un soutien efficace pour recueillir des données sur la consommation de ressources de calcul (par exemple, CPU, mémoire), ainsi que des mécanismes efficaces pour réserver des ressources pour des applications spécifiques. Dans les solutions existantes, nous trouvons deux inconvénients importants. Les solutions imposent un impact important sur les performances à l'exécution des applications. La création d'outils permettant de gérer finement les ressources pour ces abstractions est encore une tâche complexe. Les résultats de cette thèse forment trois contributions : Un cadre de surveillance des ressources optimiste qui réduit le coût de la collecte des données de consommation de ressources ; une méthodologie pour sélectionner les le support d'exécution des composants au moment du déploiement afin d’exécuter la réservation de ressources ; un langage pour construire des profileurs de mémoire personnalisées qui peuvent être utilisés à la fois au cours du développement des applications, ainsi que dans un environnement de production. / Software systems are more pervasive than ever nowadays. Occasionally, applications run on top of resource-constrained devices where efficient resource management is required ; hence, they must be capable of coping with such limitations. However, applications require support from the run-time environment to properly deal with resource limitations. This thesis addresses the problem of supporting resource-aware programming in execution environments. In particular, it aims at offering efficient support for collecting data about the consumption of computational resources (e.g., CPU, memory), as well as efficient mechanisms to reserve resources for specific applications. In existing solutions we find two important drawbacks. First, they impose performance overhead on the execution of applications. Second, creating resource management tools for these abstractions is still a daunting task. The outcomes of this thesis are three contributions: an optimistic resource monitoring framework that reduces the cost of collecting resource consumption data ; a methodology to select components' bindings at deployment time in order to perform resource reservation ; a language to build customized memory profilers that can be used both during applications' development, and also in a production environment.

No / Fairness in bandwidth resource allocation is highly significance to the advancement of the future generation mobile and wireless technologies. It is likely that restriction of bandwidth due to the employment of some scheduling scheme would not be an appropriate option for the future development of communication systems. However, there is need to consider an implementation that would lead to good network performance and avoid unguaranteed bandwidth delivery. This paper focusses on evaluating the performance of Bandwidth Allocation using Dynamic Label Switching Paths (LSPs) Tunnelling and Label Distribution Protocol (LDP) signalling in Multi-Protocol Label Switching (MPLS) network. This will make provision for bandwidth allocation and reservation possible. An appropriate bandwidth allocation would have a positive impact on throughput as well as the delay. The results of an IP (Internet Protocol) Network without MPLS enabled is compared with MPLS model network. Furthermore, implementation of dynamic and static LSPs models are presented with about 75% decrease in packet delay variation for dynamic LSP when compared from static LSP. In addition, the models of bandwidth estimation, bandwidth allocation, delay and jitter are provided. Performance metrics used in this respect for multimedia services (Voice and Video conferencing) confirm that the modified models are improved in comparison with the baseline, having highest throughput of about 51% increment, and packet delay variation decreases drastically.

[pt] Nas últimas décadas, tem-se observado um crescente interesse nas tecnologias relacionadas a ambientes de comunicação móvel sem fio. Em grande parte, esse interesse vem acompanhando o crescimento do mercado de telecomunicações, mais especificamente dos sistemas de telefonia móvel celular. Os usuários vêm absorvendo rapidamente essas tecnologias, originando novas necessidades, como a utilização de serviços de dados multimídia, que exige garantias de qualidade. Nesse contexto, um dos desafios encontrados é conseguir a utilização eficiente do limitado espectro de freqüências disponível, fornecendo serviços com qualidade para os usuários. Esta dissertação propõe uma arquitetura para provisão de qualidade de serviço -QoS- fim-a-fim em redes móveis sem fio, levando em consideração características inerentes a esses ambientes. Para alcançar esse objetivo, são propostas modificações aos frameworks para provisão de QoS em ambientes genéricos de processamento e comunicação, visando atender às necessidades trazidas pelas redes móveis, gerando uma arquitetura adaptável para fornecer QoS em ambientes que ofereçam suporte à mobilidade. Uma instanciação dos frameworks para provisão de QoS em redes móveis sem fio é descrita através de um cenário de mobilidade, no qual é simulada uma rede infraestruturada de serviços integrados funcionando sobre o IP Móvel, de modo a validar a peoposta. / [en] In the last decades, increasing interest has been observed in technologies related to wireless mobile communication environments. Great part of such interest follows the growth in the telecommunications industry, more specifically of cellular mobile telephony systems. Users are quickly absorbing these technologies and generating new necessities, such as the use of services of multimedia data, which demand quality assurance. In this context, one of the challenges is the efficient use of the limited frequency spectrum available, providing users quality services. This thesis proposes an architecture for the provision of end-to-end QoS in wireless mobile networks, taking into account inherent characteristics of these environments. To reach this purpose, modifications were proposed to the frameworks for QoS provisioning in generic processing and communication environments, aiming to fulfill the necessities brought by mobile networks, generating an adaptable architecture to offer QoS in environments that support mobile connections. In order to validate the proposal, an instantiation of frameworks for QoS provisioning in wireless mobile networks is described by means of a mobility scenario in which an infrastructure network of integrated services is simulated working over Mobile IP.

Se propone una metodología de desarrollo de aplicaciones de tiempo real estricto que van a ser ejecutadas en plataformas distribuidas abiertas. En esta metodología, el diseñador de la aplicación no conoce la carga de trabajo de la plataforma que será ejecutada concurrentemente junto con la aplicación que diseña. La metodología se basa en el paradigma de reserva de recursos, y utiliza como base el concepto de plataforma virtual, tanto para describir el uso de los recursos que una aplicación requiere, como para ejecutar la aplicación satisfaciendo sus requisitos temporales. La plataforma virtual es utilizada en el proceso de negociación con el servicio de reserva de recursos de la plataforma física, con objeto de obtener una configuración de la aplicación que haga compatible su ejecución con la carga de trabajo que ya se está ejecutando en dicha plataforma. La metodología aborda todas las fases del desarrollo de una aplicación: describe la información que debe asociarse al código de la aplicación para poder ser configurado, así como el proceso que permite analizar independientemente su planificabilidad en base a la plataforma virtual; especifica el proceso de despliegue de la aplicación y define la información que se utiliza para negociar su ejecución con el servicio de reserva de recursos de la plataforma física y para generar los datos de configuración que deben ser asignados al código cuando se ejecute. Todos estos procesos son dirigidos por modelos, por lo que la tesis aborda la definición de las transformaciones de modelos requeridas, así como la formulación de los metamodelos formales utilizados en ellas. Por otro lado, aunque la tecnología es independiente de la plataforma de ejecución, se especifica la funcionalidad que debe ofrecer el servicio de reserva de recursos presente en la misma para dar soporte a la metodología propuesta, y se analiza su compatibilidad con algunas implementaciones actualmente disponibles / This thesis proposes a methodology for the development of hard real-time applications that will be executed in open distributed platforms. When this methodology is applied, the application designer does not know the workload of the platform that will execute concurrently with the designed application. The methodology is based on the resource reservation paradigm, and relies on the concept of virtual platform, both to describe the resources usage required by an application to execute, and to run the application guaranteeing the fulfillment of the specified timing requirements. The virtual platform is also used on the negotiation process with the resource reservation service of the physical platform in order to obtain a configuration of the application that supports its execution together with the current workload running on that platform. The methodology deals with all the phases of the application design: it describes the information that must be associated to the application code in order to obtain a proper configuration, as well as the process that allows an independent schedulability analysis of the application based on its virtual platform; it specifies the application deployment process and defines the information that is used to negotiate the execution of the application with the resource reservation service of the physical platform, and to generate the configuration data that must be assigned to the code when it is executed. The methodology follows a model-driven perspective, so the thesis addresses the required models transformations, as well as the formulation of the metamodels used in them. Moreover, although the technology is independent from the execution platform, the functionality that must be provided by the resource reservation service to support the proposed technology is specified and its compatibility with other implementations is analyzed.

Tato práce se zabývá technologií Multiprotocol Label Switching a to zejména moderními metodami, které je možné použít v rámci této technolologie. Jako příklad lze uvést využití podpory kvality služeb při směrování. V práci jsou navrhnuty a simulovány různé topologie a scénáře, které ověřují možnosti využití MPLS v podpoře kvality služeb.