Dissertations / Theses on the topic 'Migration dans le Cloud'
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1
Djiken, Guy Lahlou. "La mobilité du code dans les systèmes embarqués." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1112/document.
Abstract:
Avec l’avènement du nomadisme, des périphériques mobiles, de la virtualisation et du Cloud Computing ces dernières années, de nouvelles problématiques sont nées aux vues des considérations écologiques, de la gestion d’énergie, de la qualité de service, des normes sécuritaires et bien d’autres aspects liés à nos sociétés. Pour apporter une solution à ces problèmes, nous avons défini la notion de Cloudlet tel un Cloud local où peuvent se virtualiser des périphériques et ses applications embarquées. Ensuite, nous avons conçu une architecture distribuée basée sur ce pattern d’architecture lié au Cloud Computing et à la virtualisation de ressources. Ces définitions permettent de placer notre travail par rapport aux autres approches de déportation d’applications mobiles.D’autre part, un réseau de Cloudlets permet la protection de l’activité effectuée sur un périphérique mobile par la déportation d’applications embarquées dans une machine virtuelle s’exécutant dans la Cloudlet, ainsi que le suivi des usagers dans leur déplacement.Ces définitions nous ont guidées dans l’écriture de spécifications formelles via une algèbre de processus d’ordre supérieure. Elles autorisent le calcul de la sémantique opérationnelle pour les différentes études de cas basées sur ce concept de Cloudlet. Ces spécifications ont permis de décrire une nouvelle vision de la composition des périphériques virtuels applicables à tous les périphériques, les capteurs ou les actuateurs. L’ensemble des équations obtenues constitue une définition formelle de référence non seulement pour le prototypage d’une Cloudlet mais aussi pour la construction des automates temporisés.En se basant sur la structure de nos spécifications, nous avons construit un modèle d’automates temporisés pour un réseau de Cloudlets. Par l’emploi de technique de model checking, nous avons établi des propriétés temporelles montrant que toute exécution d’une application mobile sur un périphérique mobile pouvait être déportée dans une Cloudlet sous condition d’une structure applicative. Ces travaux ont abouti à des choix techniques donnant lieu à un prototype d’une telle architecture distribuée par l’emploi de serveurs OSGi. D’une part, nous fournissons une architecture logicielle d’application mobile. D’autre part, nous mettons en œuvre le principe de migration vers une Cloudlet voisine et son retour. Ces résultats sont une validation de nos choix initiaux et attestent de la réalité de nos travaux. Ils autorisent la prise de mesure permettant de définir le coût d’une migration vers une Cloudlet pendant une exécution, ainsi que son suivi au cours du déplacement de l’usagerWith the advent of nomadism, mobile devices, virtualization and cloud computing in recent years, new problems have arisen taking into account ecological concerns, energy management, quality of service, security standards and many other aspects related to our societies. To solve these problems, we define the concept of Cloudlet as a local cloud where virtual devices and embedded applications can be virtualized. Then, we design a distributed architecture based on this architectural pattern related to cloud computing and virtualization of resources. These notions allow us to position our work among other approaches to offload mobile applications in a Cloudlet.On the other hand, a network of Cloudlets helps to secure the activity carried out on a mobile device by offloading embedded applications in a running virtual machine in the Cloudlet, and also to monitor users during their movements.These definitions guided us towards writing formal specifications via a higher order processes of algebra. They facilitate the calculation of operational semantics for different case studies based on this Cloudlet concept. These specifications foster a new vision for designing virtual devices suitable to all devices, sensors or actuators. This set of equations constitutes a formal definition relevant not only for prototyping a Cloudlet but also for constructing a timed automata system.Following the structure of our specifications, we built a model of timed automata for a network of Cloudlets. Exploiting the model checking techniques, we have established temporal properties showing that any execution of a mobile application on a mobile device could be offloaded in a Cloudlet depending on a given software architecture. This work resulted in making technical choices leading to a prototype of such a distributed architecture using an OSGi server. A first result leads us to define a software architecture for mobile applications. Secondly, we implement the principle of migration to a Cloudlet neighbor. Our tests validate our initial choices and confirm the hypotheses of our work. They allow taking measures in order to assess the cost of an offloading to a Cloudlet during runtime, as well as keeping track during user’s movements
2
Oulaaffart, Mohamed. "Automating Security Enhancement for Cloud Services." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0232.
Abstract:
Les avancées des techniques de virtualisation et la maturité des langages d'orchestration ont contribué à la conception et au déploiement de services cloud composites. Ces services cloud peuvent être sujets à des changements dans le temps, en raison de la migration de leurs ressources. Cela peut introduire de nouvelles vulnérabilités, qui compromettent un service cloud dans son ensemble. Dans ce contexte, cette thèse propose d'améliorer et d'automatiser la sécurité des services cloud composites selon trois axes principaux. Le premier axe consiste en un framework de sécurité automatique basé sur SMT pour prendre en charge les migrations dans les services cloud composites, comme ceux orchestrés avec le langage TOSCA (Topology and Orchestration Specification for Cloud Applications). Il s'appuie sur des techniques de vérification pour évaluer automatiquement les changements de configuration qui affectent les composants des services cloud pendant leurs migrations, déterminer les vulnérabilités potentielles et sélectionner des contre-mesures adéquates. Le deuxième axe étudie la conception d'un tiers de confiance inter-cloud, appelé C3S-TTP (Composite Cloud Configuration Security-Trusted Third Party). Celui-ci est capable de réaliser une évaluation précise et exhaustive des vulnérabilités, tout en limitant les informations partagées entre le fournisseur cloud et le client cloud. Le troisième axe est centré sur l'investigation d'une stratégie défensive par cible mouvante qui combine des algorithmes d'intelligence artificielle avec des techniques de vérification. Le but est de compromettre les activités de reconnaissance effectuées par les attaquants à travers une large exploration des états, tout en minimisant l'apparition de nouvelles vulnérabilités qui peuvent avoir un impact important sur la surface d'attaques des services cloud concernésThe advances in virtualization techniques and the maturity of orchestration languages have contributed to the design and deployment of cloud composite services. These cloud services may be subject to changes over time, due to the migration of their resources. This may introduce new vulnerabilities, that compromise the whole services. In that context, this thesis proposes to enhance and automate the security of cloud composite services, according to three main axes. The first axis consists in an automated SMT-based security framework for supporting migrations in cloud composite services, such as those orchestrated with the TOSCA (Topology and Orchestration Specification for Cloud Applications) language. It relies on verification techniques for automatically assessing the configuration changes that affect the components of cloud services during their migrations and determining adequate countermeasures. The second axis investigates the design of an inter-cloud trusted third party, called C3S-TTP (Composite Cloud Configuration Security-Trusted Third Party). This one is capable to perform a precise and exhaustive vulnerability assessment, without requiring the cloud provider and the cloud tenant to share critical configuration information between each other. The third axis is centered on the investigation of a moving target defense strategy which combines artificial intelligence algorithms together with verification techniques. The purpose is to deceive reconnaissance activities performed by attackers through a large exploration of states, while minimizing the occurrence of new vulnerabilities that may impact on the attack surface of cloud composite services
3
Rosinosky, Guillaume. "Élasticité de l’exécution des processus métier." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0003/document.
Abstract:
La disponibilité de plateformes middleware dans le cloud, avec un passage à l'échelle transparent est un vrai progrès pour les développeurs et les intégrateurs logiciels. Ils peuvent développer et déployer leurs applications sans s'inquiéter des détails opérationnels. Cependant, le coût d'exploitation d'une infrastructure dans le cloud peut devenir rapidement important. Les fournisseurs doivent disposer de méthodes pour le réduire en adaptant la taille des ressources aux besoins des clients. Dans cette thèse, nous nous focalisons sur les applications Web multi-tenant transactionnelles, plus particulièrement les moteurs d'exécution de processus métiers. Nous proposons des méthodes permettant d'optimiser les coûts opérationnels d'un fournisseur d'exécution de processus "en tant que service" (BPMaaS) tout en assurant un niveau suffisant de qualité de service. Ce type d'applications ne passe pas facilement à l'échelle à cause de sa couche persistance et de la nature transactionnelle des opérations. Il faut distribuer les installations des clients de manière à optimiser les coûts et éventuellement les déplacer en fonction de l'évolution de la charge. Ces déplacements (ou migrations) ont un impact sur la qualité de service et il faut les limiter. Dans un premier temps, nous proposons une méthode de mesure de la capacité des ressources du cloud en termes de débit d'exécution de tâches BPM, puis nous proposons une méthode de mesure de l'impact des migrations que nous avons évalué, ceci confirmant nos hypothèses. Ensuite, nous proposons plusieurs modèles d'optimisation linéaire, ainsi que des heuristiques d'allocation de ressources et de distribution des clients prenant en compte le coût de l'infrastructure, la capacité des ressources et les besoins des clients, tout en limitant les nombres de migrations. Ces modèles sont fondés sur la connaissance de l'évolution de la charge des clients par unité de temps. Nous avons expérimenté les trois méthodes que nous avons proposées sur la solution BPM Bonita, et montré qu'elles permettent des gains substantiels sur l'exploitation de l'infrastructure par rapport à une méthode basiqueThe availability of middleware platforms in the cloud, with "transparent" scalability, is a progress for software developers and integrators. They can develop and deploy their applications without worrying about technical details. However, the exploitation cost of a cloud infrastructure can quickly become important. Providers requires methods to reduce this cost by adapting the size of ressources to the needs of the customers. In this thesis, we focus on multi-tenant transactional web applications, more precisely on business processes execution engines. We propose methods allowing to optimize the operational costs of providers of business process execution "as a Service" (BPMaaS) while ensuring a sufficient level of quality of service. This type of application do not scale well because of its persistence tier and of the transactional nature of operations. One must distribute the customers installations in order to optimize the cost, and sometimes move them depending of the needs of the customers. These moves (or migrations) have an impact on the quality of service and they must be limited. First, we propose a method for measuring the size of resources in terms of BPM tasks throughput, and then a method for measuring the impact of migrations we evaluate, thus confirming our hypothesis. We also propose several linear optimization models and heuristics targeting resouce allocation and distribution of customers, while limiting the number of migrations. These models are based on the knowledge of the needs of customers per time slot. We have experimented our three methods on the BPM solution Bonita, and demonstrated that they provide substantial savings on the infrastructure exploitation compared to a basic method
4
Thiam, Cheikhou. "Anti load-balancing for energy-aware distributed scheduling of virtual machines." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2441/.
Abstract:
La multiplication de l'informatique en nuage (Cloud) a abouti à la création de centres de données dans le monde entier. Le Cloud contient des milliers de nœuds de calcul. Cependant, les centres de données consomment d'énorme quantités d'énergie à travers le monde estimées à plus de 1,5 % de la consommation mondiale d'électricité et devrait continuer à croître. Une problématique habituellement étudiée dans les systèmes distribués est de répartir équitablement la charge. Mais lorsque l'objectif est de réduire la consommation électrique, ce type d'algorithmes peut mener à avoir des serveurs fortement sous chargés et donc à consommer de l'énergie inutilement. Cette thèse présente de nouvelles techniques, des algorithmes et des logiciels pour la consolidation dynamique et distribuée de machines virtuelles (VM) dans le Cloud. L'objectif principal de cette thèse est de proposer des stratégies d'ordonnancement tenant compte de l'énergie dans le Cloud pour les économies d'énergie. Pour atteindre cet objectif, nous utilisons des approches centralisées et décentralisées. Les contributions à ce niveau méthodologique sont présentées sur ces deux axes. L'objectif de notre démarche est de réduire la consommation de l'énergie totale du centre de données en contrôlant la consommation globale d'énergie des applications tout en assurant les contrats de service pour l'exécution des applications. La consommation d'énergie est réduite en désactivant et réactivant dynamiquement les nœuds physiques pour répondre à la demande des ressources. Les principales contributions sont les suivantes: - Ici on s'intéressera à la problématique contraire de l'équilibrage de charge. Il s'agit d'une technique appelée Anti Load-Balancing pour concentrer la charge sur un nombre minimal de nœuds. Le but est de pouvoir éteindre les nœuds libérés et donc de minimiser la consommation énergétique du système. - Ensuite une approche centralisée a été proposée et fonctionne en associant une valeur de crédit à chaque nœud. Le crédit d'un nœud dépend de son affinité pour ses tâches, sa charge de travail actuelle et sa façon d'effectuer ses communications. Les économies d'énergie sont atteintes par la consolidation continue des machines virtuelles en fonction de l'utilisation actuelle des ressources, les topologies de réseaux virtuels établis entre les machines virtuelles et l'état thermique de nœuds de calcul. Les résultats de l'expérience sur une extension de CloudSim (EnerSim) montrent que l'énergie consommée par les applications du Cloud et l'efficacité énergétique ont été améliorées. - Le troisième axe est consacré à l'examen d'une approche appelée "Cooperative scheduling Anti load-balancing Algorithm for cloud". Il s'agit d'une approche décentralisée permettant la coopération entre les différents sites. Pour valider cet algorithme, nous avons étendu le simulateur MaGateSim. Avec une large évaluation expérimentale d'un ensemble de données réelles, nous sommes arrivés à la conclusion que l'approche à la fois en utilisant des algorithmes centralisés et décentralisés peut réduire l'énergie consommée des centres de donnéesThe multiplication of Cloud computing has resulted in the establishment of largescale data centers around the world containing thousands of compute nodes. However, Cloud consume huge amounts of energy. Energy consumption of data centers worldwide is estimated at more than 1. 5% of the global electricity use and is expected to grow further. A problem usually studied in distributed systems is to evenly distribute the load. But when the goal is to reduce energy consumption, this type of algorithms can lead to have machines largely under-loaded and therefore consuming energy unnecessarily. This thesis presents novel techniques, algorithms, and software for distributed dynamic consolidation of Virtual Machines (VMs) in Cloud. The main objective of this thesis is to provide energy-aware scheduling strategies in cloud computing for energy saving. To achieve this goal, we use centralized and decentralized approaches. Contributions in this method are presented these two axes. The objective of our approach is to reduce data center's total energy consumed by controlling cloud applications' overall energy consumption while ensuring cloud applications' service level agreement. Energy consumption is reduced by dynamically deactivating and reactivating physical nodes to meet the current resource demand. The key contributions are: - First, we present an energy aware clouds scheduling using anti-load balancing algorithm : concentrate the load on a minimum number of severs. The goal is to turn off the machines released and therefore minimize the energy consumption of the system. - The second axis proposed an algorithm which works by associating a credit value with each node. The credit of a node depends on its affinity to its jobs, its current workload and its communication behavior. Energy savings are achieved by continuous consolidation of VMs according to current utilization of resources, virtual network topologies established between VMs, and thermal state of computing nodes. The experiment results, obtained with a simulator which extends CloudSim (EnerSim), show that the cloud application energy consumption and energy efficiency are being improved. - The third axis is dedicated to the consideration of a decentralized dynamic scheduling approach entitled Cooperative scheduling Anti-load balancing Algorithm for cloud. It is a decentralized approach that allows cooperation between different sites. To validate this algorithm, we have extended the simulator MaGateSim. With an extensive experimental evaluation with a real workload dataset, we got the conclusion that both the approach using centralized and decentralized algorithms can reduce energy consumed by data centers
5
Aissioui, Abdelkader. "Le chemin vers les architectures futures des services mobiles : du Follow Me Cloud (FMC) au Follow Me edge Cloud (FMeC)." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV095.
Abstract:
Les travaux décrits dans cette thèse de doctorat visent à traiter les futures architectures de fourniture de services mobiles basés sur le cloud, à travers l'évolution des infrastructures réseau partant de Mobile Cloud Computing (MCC) au Mobile Edge Computing (MEC). Nous nous sommes essentiellement concentrés sur le concept Follow Me Cloud (FMC) comme une nouvelle stratégie de fourniture de services pour une meilleure expérience utilisateur et une utilisation efficace des ressources. Cela permet aux services basés sur le cloud de "suivre" leurs utilisateurs mobiles au cours de leurs déplacements à travers les technologies de réseau d'accès, tout en fournissant le service basé sur le cloud via le point de service le plus optimal au sein de l'infrastructure cloud. Plusieurs contributions sont proposées dans cette thèse, avec des évaluations à la fois en analyse théorique et en simulation scientifique.Premièrement, nous avons proposé une architecture alternative FMC qui permet: (i) d'ouvrir la conception FMC sur les technologies d'accès réseau mobile non-3GPP (ii) d'assurer l'interopérabilité entre différents domaines PMIPv6 permettant au MN une itinérance inter-domaines PMIPv6 avec une mobilité IP transparente ainsi qu'une continuité de session de service.(iii) d'offrir une architecture sans tunnel dans les situations d'itinérance de MN, en évitant ainsi toute surcharge supplémentaire liée aux tunnels dans la gestion de la mobilité. Le schéma proposé exploite la technologie SDN/OpenFlow et le protocole de gestion de la mobilité PMIPv6 en les intégrant dans un unique framework permettant de réaliser la vision FMC.Deuxièmement, pour aborder les problèmes d'évolutivité et de résilience dans les architectures SDN/OpenFlow centralisées de plan de contrôle, nous avons introduit une nouvelle conception d'un contrôleur SDN élastique et distribué adapté pour MCC et plus particulièrement pour les systèmes de gestion FMC. Nous avons illustré comment le nouveau schéma de plan de contrôle est distribué sur une architecture hiérarchique à deux niveaux, un premier niveau avec un seul contrôleur SDN global et un second niveau avec plusieurs contrôleurs SDN locaux. Ensuite, nous avons présenté les éléments constitutifs de notre nouvel framework de plan contrôle, le calcul de l'indicateur de performance (KPI) du système, et nous avons fixé l'objectif clé de notre conception visant à maintenir la valeur KPI du système dans une fenêtre de seuil prédéfinie. Enfin, nous avons démontré comment cet objectif est atteint en adaptant dynamiquement le nombre et l'emplacement des contrôleurs SDN locaux en utilisant la technologie NFV pour provisionner les contrôleurs SDN en tant que instances VNF (fonction réseau virtuelle) dans le cloud.Troisièmement, nous avons introduit le concept FMeC, exploitant les capacités offertes par la combinaison des architectures MEC et FMC dans le but de satisfaire aux exigences des systèmes automobiles 5G. Nous avons commencé par définir les éléments clés du concept FMeC permettant de fournir la technologie FMC en bordure des réseaux mobiles. Ensuite, nous avons présenté une projection de notre solution FMeC sur un cas d'utilisation de conduite automatisée intégrant l'industrie automobile aux infrastructures Telecom en vue de la vision automobile 5G future. Avec une focalisation sur les types de communications V2I/N, nous avons présenté la conception de notre architecture FMeC basée sur les technologies SDN/OpenFlow et les entités de l'infrastructure MEC dont les ressources sont mises en commun pour fournir un cloud de bordure fédéré. Enfin, nous avons présenté notre framework sensible à la mobilité pour le placement des services dans le cloud de bordure, ce dernier est fondé sur un ensemble d'algorithmes de base qui permettent d'atteindre les exigences de QoS de la conduite automatisée en termes de latence ultra-courte au sein du réseau 5GThis Ph.D. thesis aims to deal with the future delivery architectures of mobile cloud-based services, through network infrastructures evolving from Mobile Cloud Computing (MCC) to Mobile Edge Computing (MEC). We mainly focused on Follow Me Cloud (FMC) concept as a new service delivery strategy for improved user experience and efficient resource utilization. That enables cloud-based services to follow their mobile users during their movement across access network technologies and by delivering the cloud-service via the optimal service point inside the cloud infrastructure. Several contributions are proposed in this thesis and evaluated in both theoretical analysis and scientific simulation.First, we proposed an alternative FMC architecture that allows: (i) to open the FMC design on non-3GPP mobile network access technologies (ii) to provide interoperability among different PMIPv6 domains permitting MNs inter-PMIPv6 domain roaming with seamless IP mobility and service session continuity (iii) to offer a tunnel-free architecture in MNs roaming situation, avoiding any additional overhead associated with tunneling in mobility management. This proposed scheme leverage SDN/OpenFlow technology and PMIPv6 mobility management protocol by integrating them within a framework permitting to realize the FMC vision.Second, to address the scalability and resiliency concerns in centralized SDN/OpenFlow control plane architecture, we introduced a new design of an elastic distributed SDN controller tailored for Mobile Cloud Computing (MCC) and more notably for Follow Me Cloud (FMC) management systems. We illustrated how the new control plane scheme is distributed on two-level hierarchical architecture, a first level with a single global SDN controller and a second level with several local SDN controllers. Then, we presented the building blocks of our novel control plane framework, the system Key Performance Indicator (KPI) computation and set the key objective of our design aiming to keep the system KPI value within a predefined threshold window. Last, we proved how this goal is achieved by adapting the number of local SDN controllers and their locations in an elastic manner and deploying them as VNF instances on the cloud thanks to NFV technology.Third, we introduced FMeC concept, leveraging the intertwining of MEC and FMC architectures with the aim of sustaining requirements of the 5G automotive systems. We began by defining FMeC key concept elements permitting to provide FMC technology at the edge of mobile networks. Then, we presented an automated driving use case projection of our FMeC solution integrating automotive with Telco infrastructures towards the future 5G automotive vision. Focusing on the V2I/N communications types, we introduced our FMeC design architecture based on SDN/OpenFlow technologies and MEC infrastructure entities whose resources are pooled together to provide a federated edge clouds. Finally, we presented our mobility-aware framework for edge-cloud service placement based on a set of basic algorithms that permit achieving the automated driving QoS requirements in terms of ultra-short latency within 5G network
6
Rosinosky, Guillaume. "Élasticité de l’exécution des processus métier." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0003.
Abstract:
La disponibilité de plateformes middleware dans le cloud, avec un passage à l'échelle transparent est un vrai progrès pour les développeurs et les intégrateurs logiciels. Ils peuvent développer et déployer leurs applications sans s'inquiéter des détails opérationnels. Cependant, le coût d'exploitation d'une infrastructure dans le cloud peut devenir rapidement important. Les fournisseurs doivent disposer de méthodes pour le réduire en adaptant la taille des ressources aux besoins des clients. Dans cette thèse, nous nous focalisons sur les applications Web multi-tenant transactionnelles, plus particulièrement les moteurs d'exécution de processus métiers. Nous proposons des méthodes permettant d'optimiser les coûts opérationnels d'un fournisseur d'exécution de processus "en tant que service" (BPMaaS) tout en assurant un niveau suffisant de qualité de service. Ce type d'applications ne passe pas facilement à l'échelle à cause de sa couche persistance et de la nature transactionnelle des opérations. Il faut distribuer les installations des clients de manière à optimiser les coûts et éventuellement les déplacer en fonction de l'évolution de la charge. Ces déplacements (ou migrations) ont un impact sur la qualité de service et il faut les limiter. Dans un premier temps, nous proposons une méthode de mesure de la capacité des ressources du cloud en termes de débit d'exécution de tâches BPM, puis nous proposons une méthode de mesure de l'impact des migrations que nous avons évalué, ceci confirmant nos hypothèses. Ensuite, nous proposons plusieurs modèles d'optimisation linéaire, ainsi que des heuristiques d'allocation de ressources et de distribution des clients prenant en compte le coût de l'infrastructure, la capacité des ressources et les besoins des clients, tout en limitant les nombres de migrations. Ces modèles sont fondés sur la connaissance de l'évolution de la charge des clients par unité de temps. Nous avons expérimenté les trois méthodes que nous avons proposées sur la solution BPM Bonita, et montré qu'elles permettent des gains substantiels sur l'exploitation de l'infrastructure par rapport à une méthode basiqueThe availability of middleware platforms in the cloud, with "transparent" scalability, is a progress for software developers and integrators. They can develop and deploy their applications without worrying about technical details. However, the exploitation cost of a cloud infrastructure can quickly become important. Providers requires methods to reduce this cost by adapting the size of ressources to the needs of the customers. In this thesis, we focus on multi-tenant transactional web applications, more precisely on business processes execution engines. We propose methods allowing to optimize the operational costs of providers of business process execution "as a Service" (BPMaaS) while ensuring a sufficient level of quality of service. This type of application do not scale well because of its persistence tier and of the transactional nature of operations. One must distribute the customers installations in order to optimize the cost, and sometimes move them depending of the needs of the customers. These moves (or migrations) have an impact on the quality of service and they must be limited. First, we propose a method for measuring the size of resources in terms of BPM tasks throughput, and then a method for measuring the impact of migrations we evaluate, thus confirming our hypothesis. We also propose several linear optimization models and heuristics targeting resouce allocation and distribution of customers, while limiting the number of migrations. These models are based on the knowledge of the needs of customers per time slot. We have experimented our three methods on the BPM solution Bonita, and demonstrated that they provide substantial savings on the infrastructure exploitation compared to a basic method
7
Sangupamba, Mwilu Odette. "De la business intelligence interne vers la business intelligence dans le cloud : modèles et apports méthodologiques." Electronic Thesis or Diss., Paris, CNAM, 2018. http://www.theses.fr/2018CNAM1168.
Abstract:
La BI et le cloud computing sont deux grands sujets de recherche en informatique et en système d’information en particulier. Une recherche combinant ces deux concepts est d'un intérêt double : D’une part, dans les entreprises, la BI devient de plus en plus une partie importante du système d'information qui nécessite des investissements en termes de performances de calcul et des volumes de données. D’autre part, le cloud computing offre de nouvelles opportunités pour gérer les données à des fins d’analyse.Etant donné les possibilités de cloud, la question de la migration de l'ensemble du système d’information y compris la BI est d'un grand intérêt. En particulier, les chercheurs doivent fournir aux professionnels des modèles et des méthodes qui puissent les aider à migrer vers le cloud.Que faire pour que la BI puisse fournir aux managers un service de mise à disposition de données d’analyse au travers du cloud ? La question de recherche est : Comment aider les organisations à migrer leur BI vers le cloud ?Dans cette thèse, nous répondons à cette question en utilisant l'approche science de conception (design science). Nous mettons en place une aide à la décision de la migration de la BI vers le cloud qui s'appuie sur les taxonomies. Nous proposons un modèle de guidage opérationnel qui est instancié par une taxonomie de la BI dans le cloud et dont découlent les règles pour la migration de la BI vers le cloudBI and cloud computing are two major areas of computer science research and in particular in information system. A research combining these two concepts has a double interest : On the one hand, in business, the BI becomes increasingly an important part of the information system which requires investment in terms of computing performance and data volumes. On the other hand, cloud computing offers new opportunities to manage data for analysis.Given the possibilities of cloud, migration question of the information system including BI is of great interest. In particular, researchers must provide models and methods to help professional in BI migration to the cloud.The research question is : how to migrate BI to the cloud?In this thesis, we address this issue using design science research approach. We implement a decision-making help for BI migration to the cloud based on taxonomies. We provide an operational guidance model that is instantiated by a BI taxonomy in the cloud and from that rules for BI migration to the cloud are arised
8
Sangupamba, Mwilu Odette. "De la business intelligence interne vers la business intelligence dans le cloud : modèles et apports méthodologiques." Thesis, Paris, CNAM, 2018. http://www.theses.fr/2018CNAM1168/document.
Abstract:
La BI et le cloud computing sont deux grands sujets de recherche en informatique et en système d’information en particulier. Une recherche combinant ces deux concepts est d'un intérêt double : D’une part, dans les entreprises, la BI devient de plus en plus une partie importante du système d'information qui nécessite des investissements en termes de performances de calcul et des volumes de données. D’autre part, le cloud computing offre de nouvelles opportunités pour gérer les données à des fins d’analyse.Etant donné les possibilités de cloud, la question de la migration de l'ensemble du système d’information y compris la BI est d'un grand intérêt. En particulier, les chercheurs doivent fournir aux professionnels des modèles et des méthodes qui puissent les aider à migrer vers le cloud.Que faire pour que la BI puisse fournir aux managers un service de mise à disposition de données d’analyse au travers du cloud ? La question de recherche est : Comment aider les organisations à migrer leur BI vers le cloud ?Dans cette thèse, nous répondons à cette question en utilisant l'approche science de conception (design science). Nous mettons en place une aide à la décision de la migration de la BI vers le cloud qui s'appuie sur les taxonomies. Nous proposons un modèle de guidage opérationnel qui est instancié par une taxonomie de la BI dans le cloud et dont découlent les règles pour la migration de la BI vers le cloudBI and cloud computing are two major areas of computer science research and in particular in information system. A research combining these two concepts has a double interest : On the one hand, in business, the BI becomes increasingly an important part of the information system which requires investment in terms of computing performance and data volumes. On the other hand, cloud computing offers new opportunities to manage data for analysis.Given the possibilities of cloud, migration question of the information system including BI is of great interest. In particular, researchers must provide models and methods to help professional in BI migration to the cloud.The research question is : how to migrate BI to the cloud?In this thesis, we address this issue using design science research approach. We implement a decision-making help for BI migration to the cloud based on taxonomies. We provide an operational guidance model that is instantiated by a BI taxonomy in the cloud and from that rules for BI migration to the cloud are arised
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Segalini, Andrea. "Alternatives à la migration de machines virtuelles pour l'optimisation des ressources dans les centres informatiques hautement consolidés." Thesis, Université Côte d'Azur, 2021. http://www.theses.fr/2021COAZ4085.
Abstract:
La virtualisation est une technologie de première importance dans les centres informatiques (data centers). Elle fournit deux mécanismes clés, les machines virtuelles et la migration, qui permettent de maximiser l’utilisation des ressources pour réduire les dépenses d’investissement. Dans cette thèse, nous avons identifié et étudié deux contextes où la migration traditionnelle ne parvient pas à fournir les outils optimaux pour utiliser au mieux les ressources disponibles dans un cluster : les machines virtuelles inactives et les mises à jour à grande échelle des hyperviseurs.Les machines virtuelles inactives verrouillent en permanence les ressources qui leur sont attribuées uniquement dans l’attente des (rares) demandes des utilisateurs. Ainsi, alors qu’elles sont la plupart du temps inactifs, elles ne peuvent pas être arrêtées, ce qui libérerait des ressources pour des services plus demandeurs. Pour résoudre ce problème, nous proposons SEaMLESS, une solution qui exploite une nouvelle forme de migration de VM vers un conteneur, en transformant les machines virtuelles Linux inactives en proxys sans ressources. SEaMLESS intercepte les nouvelles demandes des utilisateurs lorsque les machines virtuelles sont désactivées, reprenant de manière transparente leur exécution dès que de nouveaux signes d’activité sont détectés. De plus, nous proposons une technique facile à adopter pour désactiver les machines virtuelles basée sur une mise en swap de la mémoire de la machine virtuelle. Grâce à notre nouveau système de suspension en swap, nous sommes en mesure de libérer la majorité de la mémoire et du processeur occupés par les instances inactives, tout en offrant une reprise rapide du service.Dans la deuxième partie de la thèse, nous abordons le problème des évolutions à grande échelle des hyperviseurs. Les mises à niveau de l’hyperviseur nécessitent souvent un redémarrage de la machine, forçant les administrateurs du centre informatique à évacuer les hôtes, en déplaçant ailleurs les machines virtuelles pour protéger leur exécution. Cette évacuation est coûteuse, à la fois en termes de transferts réseau et de ressources supplémentaires nécessaires dans le centre informatique. Pour répondre à ce défi, nous proposons Hy-FiX et Multi-FiX, deux solutions de mise à niveau sur place qui ne consomment pas de ressources externes à l’hôte. Les deux solutions tirent parti d’une migration sans copie des machines virtuelles au sein de l’hôte, préservant leur état d’exécution tout au long de la mise à niveau de l’hyperviseur. Hy-FiX et Multi-FiX réalisent des mises à niveau évolutives, avec un impact limité sur les instances en cours d’exécutionServer virtualization is a technology of prime importance in contemporary data centers. Virtualization provides two key mechanisms, virtual instances and migration, that enable the maximization of the resource utilization to decrease the capital expenses in a data center. In this thesis, we identified and studied two contexts where traditional virtual instance migration falls short in providing the optimal tools to utilize at best the resource available in a cluster: idle virtual machines and largescale hypervisor upgrades.Idle virtual machines permanently lock the resources they are assigned only to await incoming user requests. Indeed, while they are most of the time idle, they cannot be shut down, which would release resources for more demanding services. To address this issue, we propose SEaMLESS, a solution that leverages a novel VM-to-container migration that transforms idle Linux virtual machines into resource-less proxies. SEaMLESS intercepts new user requests while virtual machines are disabled, transparently resuming their execution upon new signs of activity. Furthermore, we propose an easy-to-adopt technique to disable virtual machines based on the traditional hypervisor memory swapping. With our novel suspend-to-swap, we are able to release the majority of the memory and CPU seized by the idle instances, yet providing a fast resume.In the second part of the thesis, we tackle the problem of large-scale upgrades of the hypervisor software. Hypervisor upgrades often require a machine reboot, forcing data center administrators to evacuate the hosts, relocating elsewhere the virtual machines to protect their execution. As this evacuation is costly, both in terms of network transfers and spare resources needed in the data center, hypervisor upgrades hardly scale. We propose Hy-FiX and Multi-FiX, two in-place upgrade that do not consume resource external to the host. Both solutions leverage a zero-copy migration of virtual machines within the host, preserving their execution state across the hypervisor upgrade. Hy-FiX and Multi-FiX achieve scalable upgrades, with only limited impact on the running instances
10
Ema, Ismat. "Sensitive Data Migration to the Cloud." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-64736.
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Grahn, Cecilia, and Martin Sund. "Cloud computing - Moving to the cloud." Thesis, Högskolan Dalarna, Informatik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:du-12916.
Abstract:
Cloud computing innebär användning av datorresurser som är tillgängliga via ett nätverk, oftast Internet och är ett område som har vuxit fram i snabb takt under de senaste åren. Allt fler företag migrerar hela eller delar av sin verksamhet till molnet. Sogeti i Borlänge har behov av att migrera sina utvecklingsmiljöer till en molntjänst då drift och underhåll av dessa är kostsamma och tidsödande. Som Microsoftpartners vill Sogeti använda Microsoft tjänst för cloud computing, Windows Azure, för detta syfte. Migration till molnet är ett nytt område för Sogeti och de har inga beskrivningar för hur en sådan process går till. Vårt uppdrag var att utveckla ett tillvägagångssätt för migration av en IT-lösning till molnet. En del av uppdraget blev då att kartlägga cloud computing, dess beståndsdelar samt vilka för- och nackdelar som finns, vilket har gjort att vi har fått grundläggande kunskap i ämnet. För att utveckla ett tillvägagångssätt för migration har vi utfört flera migrationer av virtuella maskiner till Windows Azure och utifrån dessa migrationer, litteraturstudier och intervjuer dragit slutsatser som mynnat ut i ett generellt tillvägagångssätt för migration till molnet. Resultatet har visat att det är svårt att göra en generell men samtidigt detaljerad beskrivning över ett tillvägagångssätt för migration, då scenariot ser olika ut beroende på vad som ska migreras och vilken typ av molntjänst som används. Vi har dock utifrån våra erfarenheter från våra migrationer, tillsammans med litteraturstudier, dokumentstudier och intervjuer lyft vår kunskap till en generell nivå. Från denna kunskap har vi sammanställt ett generellt tillvägagångssätt med större fokus på de förberedande aktiviteter som en organisation bör genomföra innan migration. Våra studier har även resulterat i en fördjupad beskrivning av cloud computing. I vår studie har vi inte sett att någon tidigare har beskrivit kritiska framgångsfaktorer i samband med cloud computing. I vårt empiriska arbete har vi dock identifierat tre kritiska framgångsfaktorer för cloud computing och i och med detta täckt upp en del av kunskapsgapet där emellan.Cloud computing involves the use of computer resources that are available through a network, usually the Internet and it is an area that has grown rapidly in recent years. More and more companies move entire or part of their operations to the cloud.Sogeti in Borlänge needs to move their development environments to a cloud service as operating and maintaining of these are costly and time-consuming. As a Microsoft Partner, Sogeti wants to use Microsoft´s services for cloud computing, Windows Azure, for this purpose. Migration to the cloud is a new area for Sogeti and they do not have any descriptions of how this process works.Our mission was to develop an approach for the migration of an IT-solution to the cloud. Part of the mission included the identifying of cloud computing, its components, benefits and drawbacks, which lead to us acquiring basic knowledge of the subject.To develop an approach to migration, we performed several migrations of virtual machines to Windows Azure, and based on these migrations, literature studies and interviews we drew conclusions that resulted in an overall approach for migration to the cloud.The results have shown that it is difficult to make a general but detailed description of an approach to migration, as the scenario looks different depending on what to migrate and what type of cloud service is used. However, based on our experiences from our migrations, along with literature, documents and interviews we have lifted our knowledge to a general level. From this knowledge, we have compiled a general approach with greater focus on the preparatory activities that an organization should implement before migration.Our studies also resulted in an in-depth description of cloud computing. In our studies we did not find previous works in which the critical success factors have been described in the context of cloud computing. In our empirical work, we identified three critical success factors for cloud computing and in doing so covered up some of the knowledge gap in between.
12
Wallskog, Pappas Alexis. "Migration of Legacy Applications to the Cloud- A Review on Methodology and Tools for Migration to the Cloud." Thesis, Umeå universitet, Institutionen för datavetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96673.
Abstract:
Many organizations have legacy applications and strive to modernise them in order to react on changes and adapt to the new environment, the cloud. The enticements are quite a few but the risks are lurking as well. How to migrate a legacy application to the cloud is an unanswered question for many organizations. We look at how research has answered this question and the methods and tools they provide. The research partially answers the question of migration of legacy application to the cloud. The methods and tools are still quite granular, not that automated and is very dependent of what type of legacy application and the aim of the end result is.
13
Ellison, Martyn. "Evaluating cloud migration options for relational databases." Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/20206/.
Abstract:
Migrating the database layer remains a key challenge when moving a software system to a new cloud provider. The database is often very large, poorly documented, and used to store business-critical information. Most cloud providers offer a variety of services for hosting databases and the most suitable choice depends on the database size, workload, performance requirements, cost, and future business plans. Current approaches do not support this decision-making process, leading to errors and inaccurate comparisons between database migration options. The heterogeneity of databases and clouds means organisations often have to develop their own ad-hoc process to compare the suitability of cloud services for their system. This is time consuming, error prone, and costly. This thesis contributes to addressing these issues by introducing a three-phase methodology for evaluating cloud database migration options. The first phase defines the planning activities, such as, considering downtime tolerance, existing infrastructure, and information sources. The second phase is a novel method for modelling the structure and the workload of the database being migrated. This addresses database heterogeneity by using a multi-dialect SQL grammar and annotated text-to-model transformations. The final phase consumes the models from the second and uses discrete-event simulation to predict migration cost, data transfer duration, and cloud running costs. This involved the extension of the existing CloudSim framework to simulate the data transfer to a new cloud database. An extensive evaluation was performed to assess the effectiveness of each phase of the methodology and of the tools developed to automate their main steps. The modelling phase was applied to 15 real-world systems, and compared to the leading approach there was a substantial improvement in: performance, model completeness, extensibility, and SQL support. The complete methodology was applied to four migrations of two real-world systems. The results from this showed that the methodology provided significantly improved accuracy over existing approaches.
14
Ng, Alexander CB. "Decision Modelling and Optimization for Enterprise Migration to Clouds." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31719.
Abstract:
Many enterprises are currently exploring the possibility of migrating some or all of their IT functionalities to public clouds with the objective of reducing their overall IT service costs or to open new business frontiers. Unfortunately, making such a decision is not a straightforward task; it requires a vigorous evaluation of the various benefits, risks and costs associated with the migration of their diverse business processes that comprise of their current IT services. Yet, this problem has received very little attention in the literature, mainly due to its interdisciplinary nature.
This thesis aims at filling this gap by aiding the enterprises during the phase of making their cloud migration decision. The contributions of this work are twofold. First, a novel cloud-migration framework is introduced to guide the enterprises through a sequence of well-defined recommended analysis steps. These steps culminate with the formulation of the migration decision problem as a mathematical optimization one. The second contribution is a decision engine that efficiently solves this optimization problem.
More precisely, the proposed framework gradually guides the enterprise to first identify the various business processes that are related to their IT services and then to determine the relationship and the communication needed among those processes. The identified inter-process communication represents an indicator of how tightly coupled these business processes are to each other. When outsourcing business processes, tightly coupled processes add a high communication cost and may introduce service latency if they are not co-located. As such, inter-process communication becomes an important input parameter that affects the migration decision.
Enterprises can then determine to partially or completely migrate IT services to clouds. Furthermore, multiple vendors can be used for different services. However, when different vendors are involved, the communication cost between different processes increases. The objective is to maximize profit for an organization which includes lowering IT expenses in the long term without compromising data integrity or security. An optimization formula is finally constructed to help the enterprise determine which services to migrate given input parameters of the cost of doing business in-house, cost of outsourcing, and communication costs.
Finally, a case study is utilized to demonstrate the performance of the proposed work by analyzing the process of migrating the services to clouds for an IPTV service provider. More specifically, the case study focuses on the content delivery network (CDN) within the IPTV provider’s infrastructure which is responsible for delivering contents to viewers. The CDN network can use the proposed profit-optimization formula to determine whether to utilize a cloud service or to use its internal resource to deliver the content. A performance evaluation from a simulation is presented to demonstrate the proposed profit-optimization formula can return a set of optimal mix of both internal and external services to maximize profits.
15
Boronin, Mikhail. "Hybrid Cloud Migration Challenges. A case study at King." Thesis, Uppsala universitet, Informationssystem, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-413540.
Abstract:
Migration to the cloud has been a popular topic in industry and academia in recent years. Despite many benefits that the cloud presents, such as high availability and scalability, most of the on-premise application architectures are not ready to fully exploit the benefits of this environment, and adapting them to this environment is a non-trivial task.Therefore, many organizations consider a gradual process of moving to the cloud with Hybrid Cloud architecture. In this paper, the author is making an effort of analyzing particular enterprise case in cloud migration topics like cloud deployment, cloud architecture and cloud management.This paper aims to identify, classify, and compare existing challenges in cloud migration, illustrate approaches to resolve these challenges and discover the best practices in cloud adoption and process of conversion teams to the cloud.
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Albarrán, Munoz Isaac, and Ruiz De Azúa Manuel Parras. "Telecommunication Services’ Migration to the Cloud : Network Performance analysis." Thesis, KTH, Kommunikationssystem, CoS, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93841.
Abstract:
Nowadays, telecommunication services are commonly deployed in private networks, which are controlled and maintained by the telecommunication operators themselves, by co-location services providers, or, to some extent, by their hardware and software providers. However, with the present development of cloud computing resources, one might consider if these services could and should be implemented in the Cloud, thus taking advantage of cloud computing’s high availability, geographic distribution, and ease of usage. Additionally, this migration could reduce the telecommunication operators’ concerns in terms of hardware and network maintenance, leaving those to the Cloud computing providers who will need to supply a highly available and consistent service, to fulfill the telecommunication services’ requirements. Furthermore, virtualization provides the possibility of easily and rapidly changing the Cloud network topology facilitating the addition and removal of machines and services, allowing telecommunication services providers to adapt to their demands on the fly. The aim of this thesis project is to analyze and evaluate the level of performance, from the network point of view, that can be achieved when using Cloud computing resources to implement a telecommunication service, carrying out practical experiments both in laboratory and real environments. These measurements and analyses were conducted using an Ericsson prototype mobile switching center server (MSC-S) application, although the results obtained could be adapted to other applications with similar requirements. In order to potentially test this approach in a real environment, a prior providers’ survey was utilized to evaluate their services based on our requirements in terms of hardware and network characteristics, and thus select a suitable candidate environment for our purposes. One cloud provider was selected and its service was further evaluated based on the MSC-S application requirements. We report the results of our bench-marking process in this environment and compare them to the results of testing in a laboratory environment. The results of both sets of testing were well correlated and indicate potential for hosting telecommunication services in a Cloud environment, providing the Cloud meets the requirements imposed by the telecom services.Actualmente, los servicios de telecomunicaciones se implementan comúnmente en redes privadas, controladas y mantenidas por los operadores de telecomunicaciones, por proveedores de servicios de colocación o, hasta cierto punto, por proveedores de hardware y software. Sin embargo, con el presente desarrollo de la tecnología de ’Cloud computing’, se puede considerar la posibilidad de implementar servicios de telecomunicaciones en la nube, aprovechando su alta disponibilidad, distribución geográfica y facilidad de uso. Además, este cambio puede reducir las preocupaciones de los operadores en relación al mantenimiento del hardware y de la red, delegando en los proveedores del servicio de ’Cloud computing’, los cuáles deberán proporcionar un servicio consistente, cumpliendo así con los requisitos de los servicios de telecomunicaciones. Por otra parte, la virtualización propociona la posibilidad de cambiar rápida y fácilmente la topología de la red, facilitando la adición y supresión de maquinas y servicios, y, por tanto, permitiendo a los operadores adaptarse a sus necesidades sobre la marcha. El objetivo de esta tésis es analizar y evaluar en nivel de rendimiento, desde el punto de vista de la red, que se puede conseguir usando recursos de ’Cloud computing’ para implementar un servicio de telecomunicaciones, llevando a cabo experimentos tanto en el laboratorio como en un entorno real. Estos análisis fueron realizados utilizando un prototipo de un servidor de conmutación móvil (MSC-S) de Ericsson, aunque los resultados pueden adaptarse a otras aplicaciones con unos requisitos similares. Para probar esta propuesta en un entorno real, se realizó una encuesta de proveedores de servicios de ’Cloud computing’, con el objetivo de evaluar sus servicios teniendo en cuenta nuestros requisitos de hardware y red. Finalmente, un proveedor fue escogido y su servicio evaluado basándonos en los requisitos de la aplicación MSC-S. En este documento proporcionamos los resultados de esa evaluación y los comparamos con los obtenidos en el laboratorio. Los resultados de ambas evaluaciones fueron satisfactorios e indican la posibilidad de implementar servicios de telecomunicaciones en la nube, siempre que la nube cumpla los requisitos impuestos por dichos servicios de telecomunicaciones.
Nuförtiden är telekommunikationstjänster ofta uppsatta i privata nätverk, som kontrolleras och underhålls av teleoperatörerna själva, av samlokaliserande tjänsteleverantörer eller i viss utsträckning av deras hårdvaruoch programvaru-leverantörer. Med den nuvarande utvecklingen av Cloud Computing-resurser kan man dock överväga om dessa tjänster kan och bör genomföras i ett Cloud, vilket drar fördel av Cloud Computings höga tillgänglighet, geografiska spridning, och enkla användning. Denna migration minskar även teleoperatörernas oro angående hårdvaru- och nätverks-underhåll genom att överlåta detta till Cloud Computing-leverantörerna, som kommer att behöva leverera en hög tillgänglighet och konsekvent service för att uppfylla telekommunikationstjänsternas krav. Dessutom ger virtualisering möjlighet att enkelt och snabbt ändra ett Clouds nätverkstopologi, vilket underlättar tillägg och borttagning av maskiner och tjänster, vilket hjälper teleoperatörer att snabbt anpassa sig till deras krav. Målet med examensarbetet är att analysera och uppskatta prestandan, från nätets perspektiv, som kan uppnås vid användning av Cloud Computingresurser för att genomföra en teletjänst, genom praktiska experiment både i laboratorium och i verkligheten. Dessa mätningar och analyser utfördes med en prototyp av en Ericsson mobilomkopplingscentralserverapplikation (MSCS), även om de erhållna resultaten skulle kunna anpassas till andra program med liknande krav. För att potentiellt kunna testa denna metod i en verklig miljö användes en tidigare leverantörs undersökning för att utvärdera deras tjänster baserat på våra krav på hårdvara och nätverksegenskaper, och genom detta välja en lämplig kandidatmiljö för våra syften. En Cloud-leverantör valdes och dess tjänster utvärderades vidare baserat på MSC-Ss applikationskrav. Vi redovisar resultatet av vår testprocess i den här miljön och jämför det med resultaten av tester i laboratoriemiljö. Resultaten från båda uppsättningarna av tester var väl korrelerade och visar på potentialen av att implementera telekommunikationstjänster i en Cloud-miljö, om detta Cloud uppfyller de kraven som ställs av telekommunikationtjänsterna.
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Svärd, Petter. "Dynamic Cloud Resource Management : Scheduling, Migration and Server Disaggregation." Doctoral thesis, Umeå universitet, Institutionen för datavetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-87904.
Abstract:
A key aspect of cloud computing is the promise of infinite, scalable resources, and that cloud services should scale up and down on demand. This thesis investigates methods for dynamic resource allocation and management of services in cloud datacenters, introducing new approaches as well as improvements to established technologies.Virtualization is a key technology for cloud computing as it allows several operating system instances to run on the same Physical Machine, PM, and cloud services normally consists of a number of Virtual Machines, VMs, that are hosted on PMs. In this thesis, a novel virtualization approach is presented. Instead of running each PM isolated, resources from multiple PMs in the datacenter are disaggregated and exposed to the VMs as pools of CPU, I/O and memory resources. VMs are provisioned by using the right amount of resources from each pool, thereby enabling both larger VMs than any single PM can host as well as VMs with tailor-made specifications for their application. Another important aspect of virtualization is live migration of VMs, which is the concept moving VMs between PMs without interruption in service. Live migration allows for better PM utilization and is also useful for administrative purposes. In the thesis, two improvements to the standard live migration algorithm are presented, delta compression and page transfer reordering. The improvements can reduce migration downtime, i.e., the time that the VM is unavailable, as well as the total migration time. Postcopy migration, where the VM is resumed on the destination before the memory content is transferred is also studied. Both userspace and in-kernel postcopy algorithms are evaluated in an in-depth study of live migration principles and performance.Efficient mapping of VMs onto PMs is a key problem for cloud providers as PM utilization directly impacts revenue. When services are accepted into a datacenter, a decision is made on which PM should host the service VMs. This thesis presents a general approach for service scheduling that allows for the same scheduling software to be used across multiple cloud architectures. A number of scheduling algorithms to optimize objectives like revenue or utilization are also studied. Finally, an approach for continuous datacenter consolidation is presented. As VM workloads fluctuate and server availability varies any initial mapping is bound to become suboptimal over time. The continuous datacenter consolidation approach adjusts this VM-to-PM mapping during operation based on combinations of management actions, like suspending/resuming PMs, live migrating VMs, and suspending/resuming VMs. Proof-of-concept software and a set of algorithms that allows cloud providers to continuously optimize their server resources are presented in the thesis.
18
Do, Manh Duc. "Green Cloud - Load Balancing, Load Consolidation using VM Migration." TopSCHOLAR®, 2017. https://digitalcommons.wku.edu/theses/2059.
Abstract:
Recently, cloud computing is a new trend emerging in computer technology with a massive demand from the clients. To meet all requirements, a lot of cloud data centers have been constructed since 2008 when Amazon published their cloud service. The rapidly growing data center leads to the consumption of a tremendous amount of energy even cloud computing has better improved in the performance and energy consumption, but cloud data centers still absorb an immense amount of energy. To raise company’s income annually, the cloud providers start considering green cloud concepts which gives an idea about how to optimize CPU’s usage while guaranteeing the quality of service. Many cloud providers are paying more attention to both load balancing and load consolidation which are two significant components of a cloud data center.
Load balancing is taken into account as a vital part of managing income demand, improving the cloud system’s performance. Live virtual machine migration is a technique to perform the dynamic load balancing algorithm. To optimize the cloud data center, three issues are considered: First, how does the cloud cluster distribute the virtual machine (VM) requests from clients to all physical machine (PM) when each computer has a different capacity. Second, what is the solution to make CPU’s usage of all PMs to be nearly equal? Third, how to handle two extreme scenarios: rapidly rising CPU’s usage of a PM due to sudden massive workload requiring VM migration immediately and resources expansion to respond to substantial cloud cluster through VM requests. In this chapter, we provide an approach to work with those issues in the implementation and results. The results indicated that the performance of the cloud cluster was improved significantly.
Load consolidation is the reverse process of load balancing which aims to provide sufficient cloud servers to handle the client requests. Based on the advance of live VM migration, cloud data center can consolidate itself without interrupting the cloud service, and superfluous PMs are turned to save mode to reduce the energy consumption. This chapter provides a solution to approach load consolidation including implementation and simulation of cloud servers.
19
De, Alwis Adambarage. "Microservice-based reengineering of enterprise systems for cloud migration." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/211471/1/Adambarage_De%20Alwis_Thesis.pdf.
Abstract:
Enterprise systems, such as enterprise resource planning and customer relationship management are widely used in corporate sectors and are notoriously large and monolithic. They are challenging to decouple because they manage asynchronous, user-driven business processes and business objects (BOs) having complex structural relationships. This thesis presents the remodularization technique combined with novel microservice patterns which utilizes both semantic properties of enterprise systems, i.e., BO structure, together with syntactic features of their code, i.e., methods and interactions, for identifying suitable parts of enterprise systems which can be run as fine-grained microservices in highly scalable Cloud systems while achieving high performance characteristics.
20
Ghiselli, Nicola. "Edge-to-Cloud Service Migration in Constrained Internet of Things Scenarios." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Abstract:
In this thesis we will treat the Edge-to-Cloud services in the mobile Internet of Things context. Edge-to-Cloud services are services that, up to reach their goals, must run partially on the Cloud and partially on the Edge. This scenario has been chosen for two reasons: it is a very hop-topic nowadays, but these technologies have many treats and weakness to be solved. To refine those problems we considered some Edge-to-Cloud services and so by using some Cloud resources together with other resources, available on the IoT devices. In particular, to use Edge-to-Cloud services, we will move some resources from the Cloud to the device and so, Edge-to-Cloud service can also help the developer to make the deployment of his applications and this is an important feature in the IoT context. In this work our intent will be to make a support system for the developers and for the applications that helps to handle all the application life-cycle, offering a solution that will behave as a Middleware and so that is able to offer some service to the final applications in an almost transparent way. Between al the possible services, we focused our attention in the Migration services and so those services that allow to migrate the requests or application components. To do that we decided to split the applications in components, giving the possibility to the support system on the device to intercept the communication messages between the components. After having intercepted a message, the support system must autonomously take a decision for the application and it must decide if use a Cloud or a local resource to complete the task. Moreover, in most cases, this scenario is a constrained scenario, where the constrain are given by the application requirements. Up to offer a support system that will be more general as possible, we will introduce some user policies, by which the user will give some guidelines to the Edge-to-Cloud support system behavior.
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Dhiman, Ashok. "Analysis of on-premise to cloud computing migration strategies for enterprises." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/70796.
Abstract:
Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 72-73).
In recent years offering and maturity in Cloud Computing space has gained significant momentum. CIOs are looking at Cloud seriously because of bottom line savings and scalability advantages. According to Gartner's survey in early 2010 of 1600 CIOs around the world, Cloud computing and virtualization were on top of their list. This interest has also resulted in slew of products and services from existing IT players as well as new comers which promise to offer many solutions to pave the path towards Cloud computing adoption by enterprises. As organizations get on to the Cloud computing bandwagon they are looking at their current IT setup and looking at the best way they can take advantage of what Cloud has to offer. For a given enterprises, getting on to Cloud might be a complete new start from scratch, a limited deployment of new applications or migration of part of existing applications integrating backwards with on-premise applications. To take advantage of the Cloud, enterprise will need to define their short and long term Cloud strategy. They will need to consider factors specific to their businesses and determine their requirements, risks and benefits. Proper investigation by the enterprise will give them insight in to the benefits and specific strategy they need to follow to gain the said benefits from Cloud. This Thesis analyzes specific strategies which enterprises can adopt, both from business and technology perspective to make sure the migration and integration between on-premise and Cloud happens with minimal disruption to business and results in maximum sustainable cost benefit. It presents the current state of On-Premise IT and Cloud Computing space and then compares them to come up with enterprise specific variables based on which one can make Cloud migration decisions. Finally, Thesis presents the broad frameworks for "migration to Cloud" and confirms the same by interviewing enterprise managers involved in Cloud migration. There are various ways to slice and approach the Cloud migration - but all should take in to consideration the business processes, architecture of existing systems, architecture of available Cloud services, interoperability between on-premise and Cloud applications, maturity of Cloud and standards, short and long term cost savings, sustainability, data/security/regulation, user adoption, available Service Level Agreements (SLAs) and business criticality.
by Ashok Dhiman.
S.M.in Engineering and Management
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Chikh, Haidar. "APOLLO : A System for Proactive Application Migration in Mobile Cloud Computing." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-59623.
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Cardoso, Abílio. "Applicability of IT service management in the migration to cloud computing." Doctoral thesis, Universidade Portucalense, 2015. http://hdl.handle.net/11328/1297.
Abstract:
Tese de Doutoramento em Informática na área de Ciência Computacional.The cloud computing (CC) paradigm is transforming the way Information Technology (IT) services are provided by converting IT products into services. This modification allows the delivery of IT services to end users in a way the customers stop purchasing products and start purchasing services instead. The successful migration to this paradigm by an organization requires a deep comprehension of its own IT as well as the dynamics of CC. To this purpose, a framework aggregating the activities that must be undertaken in two groups, the on premise and the off premise, was developed. The on premise group includes the actions developed by the customer, such as the development of a strategy plan, the attainment of a detailed definition of the organization processes and services and the definition of what to migrate to the cloud. The activities developed with the support of the candidates and selected CSPs are in the off premise group. This group encompasses activities such as the providers services’, the details ‘identification of the technologies related to the implementation of the organization processes into the cloud and the analysis of the conditions of service level agreement and the contract. Furthermore, there is already an extensive set of recommendations for IT management and IT governance in general – such as the Information Technology Infrastructure Library (ITIL) and the Control Objectives for Information and related Technology (COBIT) recommendations. However, the field of CC remains poorly covered. Acknowledging this state of affairs and adding the fact that CC is concerned with IT services, not to mention the number of organizations using ITIL in order to manage their IT services, the fact that ITIL is being recognized as a set of good practices, led to the decision of studying the applicability of service management, namely ITIL, to the migration of IT services to CC. The motivation of this study is related to the circumstance that organizations can take advantage of the work already carried out, the information gathered and the management of services when implementing ITIL. Additionally, if the customer and the supplier implement ITIL, the communication between them is also improved. Accordingly, a framework to migrate IT services, applications data and infrastructures to CC has been developed and the processes of this framework have been mapped to the ITIL’s framework.
O paradigma da computação em nuvem está a transformar a forma como os serviços de Tecnologia de Informação estão a ser disponibilizados, convertendo os produtos de TI em serviços. De modo a que as organizações consigam uma migração bem-sucedida para este paradigma necessitam de uma compreensão profunda das suas tecnologias de informação bem como o conhecimento da dinâmica da computação em nuvem. Neste sentido, foi desenvolvido um framework que agrega as atividades que devem ser realizadas na migração em dois grandes conjuntos: o “on-premise” e o “off-premise”. Estes agregam as atividades que devem ser realizadas para migrar os serviços de TI de um ambiente tradicional para a computação em nuvem. O grupo “on-premise” engloba as atividades que devem ser realizadas pela organização, tais como o desenvolvimento de um plano estratégico, a descrição pormenorizada dos serviços e processos existentes bem como a definição do que deve ser migrado para a computação em nuvem. As atividades realizadas em colaboração com os provedores de serviços são englobadas no grupo “off-premise”. Este engloba atividades tais como, a elaboração de uma lista detalhada dos serviços fornecidos pelos fornecedores de serviços, a identificação dos detalhes das tecnologias utilizadas e condições dos níveis de serviço. Por outro lado, existe um grande número de recomendações relacionadas com a gestão de serviços e governança de TI em geral, tais como a ITIL e o COBIT, que, no entanto, não cobrem por completo o paradigma da computação em nuvem. Reconhecendo este problema, paralelamente com o facto do objetivo da computação em nuvem ser os serviços, o grande número de organizações que utilizam a ITIL para gerir os seus serviços de TI, a ITIL ser reconhecida como um conjunto de boas práticas mundialmente utilizadas decidiuse estudar a aplicabilidade da gestão de serviços, nomeadamente a ITIL, à migração de serviços para a computação em nuvem. A motivação para este estudo prende-se com a vantagem que as organizações podem usufruir do trabalho já realizado, da informação reunida e da gestão de serviços obtida aquando da implementação e utilização da ITIL. Adicionalmente, se o cliente e o fornecedor de serviços utilizarem a ITIL, a comunicação entre eles é também facilitada. De modo a responder às questões levantadas pela migração para a computação em nuvem e a aplicabilidade da ITIL a esta migração, foi desenvolvido um framework para suportar as organizações no processo de migração para a computação em nuvem e os processos deste framework mapeados na ITIL.
Orientação: Professor Doutor Fernando Moreira e Professor Doutor Paulo Simões.
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El, Rheddane Ahmed. "Elasticité dans le cloud computing." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GRENM003/document.
Abstract:
Les charges réelles d'applications sont souvent dynamiques. Ainsi, le dimensionnement statique de ressources est voué soit au gaspillage, s'il est basé sur une estimation du pire scénario, soit à la dégradation de performance, s'il est basé sur la charge moyenne. Grâce au modèle du cloud computing, les ressources peuvent être allouées à la demande et le dimensionnement adapté à la variation de la charge. Cependant, après avoir exploré les travaux existants, nous avons trouvé que la plupart des outils d'élasticité sont trop génériques et ne parviennent pas à répondre aux besoins spécifiques d'applications particulières. Dans le cadre de ce travail, nous utilisons des boucles autonomiques et diverses techniques d'élasticité afin de rendre élastiques différents types d'applications, à savoir un service de consolidation, un intergiciel de messagerie et une plateforme de traitement de données en temps-réel. Ces solutions élastiques ont été réalisées à partir d'applications libres et leur évaluation montre qu'ils permettent d'économiser les ressources utilisées avec un surcoût minimalReal world workloads are often dynamic. This makes the static scaling of resourcesfatally result in either the waste of resources, if it is based on the estimatedworst case scenario, or the degradation of performance if it is based on the averageworkload. Thanks to the cloud computing model, resources can be provisioned ondemand and scaling can be adapted to the variations of the workload thus achievingelasticity. However, after exploring the existing works, we find that most elasticityframeworks are too generic and fail to meet the specific needs of particularapplications. In this work, we use autonomic loops along with various elasticitytechniques in order to render different types of applications elastic, namelya consolidation service, message-oriented middleware and a stream processingplatform. These elastic solutions have been implemented based on open-sourceapplications and their evaluation shows that they enable resources’ economy withminimal overhead
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Zhang, Gong. "Data and application migration in cloud based data centers --architectures and techniques." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41078.
Abstract:
Computing and communication have continued to impact on the way we run business, the way we learn, and the way we live. The rapid technology evolution of computing has also expedited the growth of digital data, the workload of services, and the complexity of applications. Today, the cost of managing storage hardware ranges from two to ten times the acquisition cost of the storage hardware. We see an increasing demand on technologies for transferring management burden from humans to software. Data migration and application migration are one of popular technologies that enable computing and data storage management to be autonomic and self-managing.
In this dissertation, we examine important issues in designing and developing scalable architectures and techniques for efficient and effective data migration and application migration. The first contribution we have made is to investigate the opportunity of automated data migration across multi-tier storage systems. The significant IO improvement in Solid State Disks (SSD) over traditional rotational hard disks (HDD) motivates the integration of SSD into existing storage hierarchy for enhanced performance. We developed adaptive look-ahead data migration approach to effectively integrate SSD into the multi-tiered storage architecture. When using the fast and expensive SSD tier to store the high temperature data (hot data) while placing the relatively low temperature data (low data) in the HDD tier, one of the important functionality is to manage the migration of data as their access patterns are changed from hot to cold and vice versa. For example, workloads during day time in typical banking applications can be dramatically different from those during night time. We designed and implemented an adaptive lookahead data migration model. A unique feature of our automated migration approach is its ability to dynamically adapt the data migration schedule to achieve the optimal migration effectiveness by taking into account of application specific characteristics and I/O profiles as well as workload deadlines. Our experiments running over the real system trace show that the basic look-ahead data migration model is effective in improving system resource utilization and the adaptive look-ahead migration model is more efficient for continuously improving and tuning of the performance and scalability of multi-tier storage systems. The second main contribution we have made in this dissertation research is to address the challenge of ensuring reliability and balancing loads across a network of computing nodes, managed in a decentralized service computing system. Considering providing location based services for geographically distributed mobile users, the continuous and massive service request workloads pose significant technical challenges for the system to guarantee scalable and reliable service provision. We design and develop a decentralized service computing architecture, called Reliable GeoGrid, with two unique features. First, we develop a distributed workload migration scheme with controlled replication, which utilizes a shortcut-based optimization to increase the resilience of the system against various node failures and network partition failures. Second, we devise a dynamic load balancing technique to scale the system in anticipation of unexpected workload changes. Our experimental results show that the Reliable GeoGrid architecture is highly scalable under changing service workloads with moving hotspots and highly reliable in the presence of massive node failures. The third research thrust in this dissertation research is focused on study the process of migrating applications from local physical data centers to Cloud. We design migration experiments and study the error types and further build the error model. Based on the analysis and observations in migration experiments, we propose the CloudMig system which provides both configuration validation and installation automation which effectively reduces the configuration errors and installation complexity. In this dissertation, I will provide an in-depth discussion of the principles of migration and its applications in improving data storage performance, balancing service workloads and adapting to cloud platform.
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Alkhalil, Adel. "A model to support the decision process for migration to cloud computing." Thesis, Bournemouth University, 2016. http://eprints.bournemouth.ac.uk/24525/.
Abstract:
Cloud computing is an emerging paradigm for provisioning computing and IT services. Migration from traditional systems setting up to cloud computing is a strategic organisational decision that can affect organisations’ performance, productivity, and growth as well as competitiveness. Organisations wishing to migrate their legacy systems to the cloud often need to go through a difficult and complicated decision-making process. This can be due to multiple factors including restructuring IT resources, the still evolving nature of the cloud environment, and the continuous expansion of the cloud services, configurations and providers. This research explores the factors that would influence decision making for migration to the cloud, its impact on IT management, and the main tasks that organisations should consider to ensure successful migration projects. The sequential exploratory strategy is followed for the exploration. This strategy is implemented through the utilisation of a two-stage survey for collecting the primary data. The analysis of the two-stage survey as well as the literature identified eleven determinants that increase the complexity in the decisions to migrate to the cloud. In the literature some of those determinants were realised, accordingly, there have been many proposed methods for supporting migration to the cloud. However, no systematic decision making process exists that clearly identifies the main steps and explicitly describes the tasks to be performed within each step. This research aims to fill this need by proposing a model to support the decision process for migrating to cloud. The model provides a structure which covers the whole process of migration decisions. It guides decision makers through a step-by-step approach aiding organisations with their decision making. The model was evaluated by exploring the views of a group of the cloud practitioners on it. The analysis of the views demonstrated a high level of acceptance by the practitioners with regard to the structure, tasks, and issues addressed by the model. The model offers an encouraging preliminary structure for developing a cloud Knowledge-Based Decision Support System.
27
Pasumarthy, Sarat Chandra. "Live Migration of Virtual Machines in the Cloud : An Investigation by Measurements." Thesis, Blekinge Tekniska Högskola, Institutionen för kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-10770.
Abstract:
Cloud computing has grown in prevalence from recent years due to its concept of computing as a service, thereby, allowing users to offload the infrastructure management costs and tasks to a cloud provider. Cloud providers leverage server virtualization technology for efficient resource utilization, faster provisioning times, reduced energy consumption, etc. Cloud computing inherits a key feature of server virtualization which is the live migration of virtual machines (VMs). This technique allows transferring of a VM from one host to another with minimal service interruption. However, live migration is a complex process and with a cloud management software used by cloud providers for management, there could be a significant influence on the migration process. This thesis work aims to investigate the complex process of live migration performed by the hypervisor as well as the additional steps involved when a cloud management software or platform is present and form a timeline of these collection of steps or phases. The work also aims to investigate the performance of these phases, in terms of time, when migrating VMs with different sizes and workloads. For this thesis, the Kernel-based Virtual Machine (KVM) hypervisor and the OpenStack cloud software have been considered. The methodology employed is experimental and quantitative. The essence of this work is investigation by network passive measurements. To elaborate, this thesis work performs migrations on physical test-beds and uses measurements to investigate and evaluate the migration process performed by the KVM hypervisor as well as the OpenStack platform deployed on KVM hypervisors. Experiments are designed and conducted based on the objectives to be met. The results of the work primarily include the timeline of the migration phases of both the KVM hypervisor and the OpenStack platform. Results also include the time taken by each migration phase as well as the total migration time and the VM downtime. The results indicate that the total migration time, downtime and few of the phases increase with increase in CPU load and VM size. However, some of the phases do not portray any such trend. It has also been observed that the transfer stage alone does not contribute and influence the total time but every phase of the process has significant influence on the migration process. The conclusions from this work is that although a cloud management software aids in managing the infrastructure, it has notable impact on the migration process carried out by the hypervisor. Moreover, the migration phases and their proportions not only depend on the VM but on the physical environment as well. This thesis work focuses solely on the time factor of each phase. Further evaluation of each phase with respect to its resource utilization can provide better insight into probable optimization opportunities.
28
Zhu, Jiedan. "An Autonomic Framework Supporting Task Consolidation and Migration in the Cloud Environment." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1310758418.
29
Anwar, Mahwish. "Virtual Firewalling For Migrating Virtual Machines In Cloud Computing." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-6080.
Abstract:
Context. Cloud Computing (CC) uses virtualization to provide computing resources on demand via Internet. Small and large organizations benefit from CC because of reduced operating costs and increase in business agility. The migrating Virtual Machine (VM) is vulnerable from attacks such as fake migration initiations, service interruptions, manipulation of data or other network attacks. During live migration any security lax in VM firewall policy can put the VM data, OS and the applications on it at risk. A malicious VM can pose threat to other VMs in its host and consequently for VMs in LAN. Hardware firewalls only protect VM before and after migration. Plus, they are blind to virtual traffic. Hence, virtual firewalls (VFs) are used to secure VMs. Mostly; they are deployed at Virtual Machine Monitor-level (VMM) under Cloud provider’s control. Source VMM-level VF provides security to VM before the migration incurs and the destination VMM-level VF starts securing VM after migration is completed. It thus, becomes possible for attacker to use the intermediate migrating window to launch attacks on VM. Considering the potential of VFs there should be a great value in using open source VFs at VM-level for protecting VMs during migration, thereby, reducing the attacker’s slot to gain access to VM. It would enable hardened security for overall VM migration. Objectives. The aim is to investigate VM-level firewalling using open source firewall as a complementary security layer to VMM-level firewalling, to secure migrating VM in the CC domain. The first objective is to identify how virtual firewalls secure migrating VM in CC and to propose VM-level open-source virtual firewalling for protecting VM during migration. Later the VF is implemented to validate and evaluate its intactness or activeness during migration in real Cloud data center. Methods. In the literary review 9 electronic libraries are used, which include IEEE Xplore, ACM Digital Library, SCOPUS, Engineering Village and Web of Knowledge. Studies are selected after querying libraries for 2 key terms ‘virtual machine’ and ‘migration’ (along with other variations/synonyms), in the abstract. Relevant papers on the subject are read and analyzed. Finally, the information gaps are identified. Using a lacuna the experimental solution is designed. To test the potential of VF at VM-level for migrating VM’s security the experimental validation is performed using stratification samples of firewall rules. The VF evaluation is done using continuous ICMP echo packet transmission. The packets are analyzed to determine firewall behavior during migration. To evaluate the validity, the VM migration is performed 8 times in City Network data center. Results. The literary review identified the widespread use of VMM-level firewalling for migrating VM’s security in CC. The VM-level VFs were not researched nor evaluated for intactness during migration. The experiment performed at City Network demonstrated that the VM-level VF secures VM during migration (on average) for 96% of migration time, thereby reducing attack window for attacker during VM mobility. According to the results the average total migration time (TMT) was 16.6 s and average downtime (DT) of firewall was as low as 0.47 s, which means that VF at VM-level protects VM during entire migration span except when VM’s down (4% of migration time). Conclusions. The research concludes that VM-level firewalling using open source VF as an additional security layer in CC for VM migrations is feasible to employ and will enhance the migrating machine’s security by providing hardened firewall service during migration process, thus, reducing the potential attack window. VMM-level VF provides security in post and pre migration phase. Using VM-level VF as a complementary measure to VMM-level VF enables additional protection for VM migration process, thereby reducing the chances for attacker to attack VM during transition.Email: mahwish.anwar@gmail.com Twitter: Mah__Wish
ORCID ID: 0000-0001-7486-5216
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Teyeb, Hana. "Optimisation intégrée dans un environnement cloud." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLL010/document.
Abstract:
Dans les systèmes cloud géographiquement distribués, un défi majeur auquel sont confrontés les fournisseurs de cloud consiste à optimiser et à configurer leurs infrastructures. En particulier, cela consiste à trouver un emplacement optimal pour les machines virtuelles (VMs) afin de minimiser les coûts tout en garantissant une bonne performance du système. De plus, en raison des fluctuations de la demande et des modèles de trafic, il est essentiel d'ajuster dynamiquement le schéma de placement des VMs en utilisant les techniques de migration des VMs. Cependant, malgré ses avantages apportés, dans le contexte du Cloud géo-distribué, la migration des VMs génère un trafic supplémentaire dans le réseau backbone ce qui engendre la dégradation des performances des applications dans les centres de données (DCs) source et destination. Par conséquent, les décisions de migration doivent être bien étudiés et basées sur des paramètres précis. Dans ce manuscrit, nous étudions les problèmes d'optimisation liés au placement, à la migration et à l'ordonnancement des VMs qui hébergent des applications hautement corrélées et qui peuvent être placés dans des DCs géo-distribués. Dans ce contexte, nous proposons un outil de gestion de DC autonome basé sur des modèles d'optimisation en ligne et hors ligne pour gérer l'infrastructure distribuée du Cloud. Notre objectif est de minimiser le volume du trafic global circulant entre les différents DCs du système.Nous proposons également des modèles d'optimisation stochastiques et déterministes pour traiter les différents modèles de trafic de communication. En outre, nous fournissons des algorithmes quasi-optimaux qui permettent d'avoir la meilleure séquence de migration inter-DC des machines virtuelles inter-communicantes. En plus, nous étudions l'impact de la durée de vie des VMs sur les décisions de migration afin de maintenir la stabilité du Cloud. Enfin, nous utilisons des environnements de simulation pour évaluer et valider notre approche. Les résultats des expériences menées montrent l'efficacité de notre approcheIn geo-distributed cloud systems, a key challenge faced by cloud providers is to optimally tune and configure their underlying cloud infrastructure. An important problem in this context, deals with finding an optimal virtual machine (VM) placement, minimizing costs while at the same time ensuring good system performance. Moreover, due to the fluctuations of demand and traffic patterns, it is crucial to dynamically adjust the VM placement scheme over time. Hence, VM migration is used as a tool to cope with this problem. However, despite the benefits brought by VM migration, in geo-distributed cloud context, it generates additional traffic in the backbone links which may affect the application performance in both source and destination DCs. Hence, migration decisions need to be effective and based on accurate parameters. In this work, we study optimization problems related to the placement, migration and scheduling of VMs hosting highly correlated and distributed applications within geo-distributed DCs. In this context, we propose an autonomic DC management tool based on both online and offline optimization models to manage the distributed cloud infrastructure. Our objective is to minimize the overall expected traffic volume circulating between the different DCs of the system. To deal with different types of communication traffic patterns, we propose both deterministic and stochastic optimization models to solve VM placement and migration problem and to cope with the uncertainty of inter-VM traffic. Furthermore, we propose near-optimal algorithms that provide with the best inter-DCs migration sequence of inter-communicating VMs. Along with that, we study the impact of the VM's lifetime on the migration decisions in order to maintain the stability of the cloud system. Finally, to evaluate and validate our approach, we use experimental tests as well as simulation environments. The results of the conducted experiments show the effectiveness of our proposals
31
Teyeb, Hana. "Optimisation intégrée dans un environnement cloud." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLL010.
Abstract:
Dans les systèmes cloud géographiquement distribués, un défi majeur auquel sont confrontés les fournisseurs de cloud consiste à optimiser et à configurer leurs infrastructures. En particulier, cela consiste à trouver un emplacement optimal pour les machines virtuelles (VMs) afin de minimiser les coûts tout en garantissant une bonne performance du système. De plus, en raison des fluctuations de la demande et des modèles de trafic, il est essentiel d'ajuster dynamiquement le schéma de placement des VMs en utilisant les techniques de migration des VMs. Cependant, malgré ses avantages apportés, dans le contexte du Cloud géo-distribué, la migration des VMs génère un trafic supplémentaire dans le réseau backbone ce qui engendre la dégradation des performances des applications dans les centres de données (DCs) source et destination. Par conséquent, les décisions de migration doivent être bien étudiés et basées sur des paramètres précis. Dans ce manuscrit, nous étudions les problèmes d'optimisation liés au placement, à la migration et à l'ordonnancement des VMs qui hébergent des applications hautement corrélées et qui peuvent être placés dans des DCs géo-distribués. Dans ce contexte, nous proposons un outil de gestion de DC autonome basé sur des modèles d'optimisation en ligne et hors ligne pour gérer l'infrastructure distribuée du Cloud. Notre objectif est de minimiser le volume du trafic global circulant entre les différents DCs du système.Nous proposons également des modèles d'optimisation stochastiques et déterministes pour traiter les différents modèles de trafic de communication. En outre, nous fournissons des algorithmes quasi-optimaux qui permettent d'avoir la meilleure séquence de migration inter-DC des machines virtuelles inter-communicantes. En plus, nous étudions l'impact de la durée de vie des VMs sur les décisions de migration afin de maintenir la stabilité du Cloud. Enfin, nous utilisons des environnements de simulation pour évaluer et valider notre approche. Les résultats des expériences menées montrent l'efficacité de notre approcheIn geo-distributed cloud systems, a key challenge faced by cloud providers is to optimally tune and configure their underlying cloud infrastructure. An important problem in this context, deals with finding an optimal virtual machine (VM) placement, minimizing costs while at the same time ensuring good system performance. Moreover, due to the fluctuations of demand and traffic patterns, it is crucial to dynamically adjust the VM placement scheme over time. Hence, VM migration is used as a tool to cope with this problem. However, despite the benefits brought by VM migration, in geo-distributed cloud context, it generates additional traffic in the backbone links which may affect the application performance in both source and destination DCs. Hence, migration decisions need to be effective and based on accurate parameters. In this work, we study optimization problems related to the placement, migration and scheduling of VMs hosting highly correlated and distributed applications within geo-distributed DCs. In this context, we propose an autonomic DC management tool based on both online and offline optimization models to manage the distributed cloud infrastructure. Our objective is to minimize the overall expected traffic volume circulating between the different DCs of the system. To deal with different types of communication traffic patterns, we propose both deterministic and stochastic optimization models to solve VM placement and migration problem and to cope with the uncertainty of inter-VM traffic. Furthermore, we propose near-optimal algorithms that provide with the best inter-DCs migration sequence of inter-communicating VMs. Along with that, we study the impact of the VM's lifetime on the migration decisions in order to maintain the stability of the cloud system. Finally, to evaluate and validate our approach, we use experimental tests as well as simulation environments. The results of the conducted experiments show the effectiveness of our proposals
32
Azraoui, Monir. "Vérifiabilité et imputabilité dans le Cloud." Thesis, Paris, ENST, 2016. http://www.theses.fr/2016ENST0032/document.
Abstract:
Cette thèse propose de nouveaux protocoles cryptographiques, plus efficaces que l’existant, et qui permettent aux utilisateurs du nuage informatique (le cloud) de vérifier (i) la bonne conservation des données externalisées et (ii) l'exécution correcte de calculs externalisés. Nous décrivons d'abord un protocole cryptographique qui génère des preuves de récupérabilité, qui permettent aux propriétaires de données de vérifier que le cloud stocke leurs données correctement. Nous détaillons ensuite trois schémas cryptographiques pour vérifier l’exactitude des calculs externalisés en se focalisant sur trois opérations fréquentes dans les procédures de traitement de données, à savoir l’évaluation de polynômes, la multiplication de matrices et la recherche de conjonction de mots-clés. La sécurité de nos solutions est analysée dans le cadre de la sécurité prouvable et nous démontrons également leur efficacité grâce à des prototypes. Nous présentons également A-PPL, un langage de politiques pour l’imputabilité qui permet l'expression des obligations de responsabilité et de traçabilité dans un format compréhensible par la machine. Nous espérons que nos contributions pourront encourager l'adoption du cloud par les entreprises encore réticentes à l’idée d'utiliser ce paradigme prometteurThis thesis proposes more efficient cryptographic protocols that enable cloud users to verify (i) the correct storage of outsourced data and (ii) the correct execution of outsourced computation. We first describe a cryptographic protocol that generates proofs of retrievability, which enable data owners to verify that the cloud correctly stores their data. We then detail three cryptographic schemes for verifiable computation by focusing on three operations frequent in data processing routines, namely polynomial evaluation, matrix multiplication and conjunctive keyword search. The security of our solutions is analyzed in the provable security framework and we also demonstrate their efficiency thanks to prototypes. We also introduce A-PPL, an accountability policy language that allows the expression of accountability obligations into machine-readable format. We expect our contributions to foster cloud adoption by organizations still wary of using this promising paradigm
33
Azraoui, Monir. "Vérifiabilité et imputabilité dans le Cloud." Electronic Thesis or Diss., Paris, ENST, 2016. http://www.theses.fr/2016ENST0032.
Abstract:
Cette thèse propose de nouveaux protocoles cryptographiques, plus efficaces que l’existant, et qui permettent aux utilisateurs du nuage informatique (le cloud) de vérifier (i) la bonne conservation des données externalisées et (ii) l'exécution correcte de calculs externalisés. Nous décrivons d'abord un protocole cryptographique qui génère des preuves de récupérabilité, qui permettent aux propriétaires de données de vérifier que le cloud stocke leurs données correctement. Nous détaillons ensuite trois schémas cryptographiques pour vérifier l’exactitude des calculs externalisés en se focalisant sur trois opérations fréquentes dans les procédures de traitement de données, à savoir l’évaluation de polynômes, la multiplication de matrices et la recherche de conjonction de mots-clés. La sécurité de nos solutions est analysée dans le cadre de la sécurité prouvable et nous démontrons également leur efficacité grâce à des prototypes. Nous présentons également A-PPL, un langage de politiques pour l’imputabilité qui permet l'expression des obligations de responsabilité et de traçabilité dans un format compréhensible par la machine. Nous espérons que nos contributions pourront encourager l'adoption du cloud par les entreprises encore réticentes à l’idée d'utiliser ce paradigme prometteurThis thesis proposes more efficient cryptographic protocols that enable cloud users to verify (i) the correct storage of outsourced data and (ii) the correct execution of outsourced computation. We first describe a cryptographic protocol that generates proofs of retrievability, which enable data owners to verify that the cloud correctly stores their data. We then detail three cryptographic schemes for verifiable computation by focusing on three operations frequent in data processing routines, namely polynomial evaluation, matrix multiplication and conjunctive keyword search. The security of our solutions is analyzed in the provable security framework and we also demonstrate their efficiency thanks to prototypes. We also introduce A-PPL, an accountability policy language that allows the expression of accountability obligations into machine-readable format. We expect our contributions to foster cloud adoption by organizations still wary of using this promising paradigm
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Raina, Ravi. "A systems perspective on cybersecurity in the cloud : frameworks, metrics and migration strategy." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107602.
Abstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, School of Engineering, System Design and Management Program, Engineering and Management Program, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 119-124).
Cloud computing represents the next generation of disruptive technologies in computing. However, there are several barriers to massive adoption of cloud and among them security remains one of the principal concerns. Traditional failure analysis and prevention frameworks fall exceedingly short to address cybersecurity as is evident by every increasing cybersecurity breaches. New frameworks for cybersecurity are required which take a holistic view of the problem and a systems perspective. Migrating to cloud also represents a key decision point for CEO/CTO's today, especially from security perspective. The objective of this thesis is to illustrate the effectiveness of taking a Systems Approach to cybersecurity and provide a framework for migration to cloud with specific emphasis on critical cybersecurity issues pertaining to various cloud deployment models and delivery services. The thesis is divided into three phases. Firstly, it will aim to explore the major security threats and critical areas of focus for security in cloud. It will explore the major security frameworks, metrics and controls, especially the major ones from NIST, CIS and CSA. SLA's for different cloud service models will then be presented. A high level cloud migration framework strategy and framework, with special emphasis on cybersecurity will also be discussed. In the second phase, System- Theoretic Accident Model and Processes (STAMP) which is based on Systems Theory will be applied to Target security breach and key recommendations as well as new insights will be presented. The analysis will highlight the need for holistic approach and Systems Thinking to cybersecurity and new insights that are not produced by traditional methods will be presented. Finally, in the third phase, the cloud migration framework discussed in phase one will be applied to Target. A case will be made that in certain scenarios, moving the less critical applications to cloud and utilizing the security benefits of cloud can actually reduce the threat vectors and security exposures and bring IT systems from a higher risk state to lower risk state. The thesis integrates cybersecurity methods and frameworks as well as security metrics with the cloud migration strategy. Additionally, it also presents STAMP/CAST failure model for cybersecurity breaches and highlights the need for integrated view of safety and security and Systems Thinking in cybersecurity both in traditional systems and cloud.
by Ravi Raina.
S.M. in Engineering and Management
35
Medhioub, Houssem. "Architectures et mécanismes de fédération dans les environnements cloud computing et cloud networking." Thesis, Evry, Institut national des télécommunications, 2015. http://www.theses.fr/2015TELE0009/document.
Abstract:
Présenté dans la littérature comme une nouvelle technologie, le Cloud Computing est devenu incontournable dans la mise en place et la fourniture des services informatiques. Cette thèse s’inscrit dans le contexte de cette nouvelle technologie qui est en mesure de transformer la mise en place, la gestion et l’utilisation des systèmes d’information. L'adoption et la vulgarisation du Cloud ont été ralenties par la jeunesse même des concepts et l'hétérogénéité des solutions existantes. Cette difficulté d'adoption se manifeste par l'absence de standard, l'hétérogénéité des architectures et des API, le Vendor Lock-In imposé par les leaders du marché et des manques qui ralentissent la fédération. La motivation principale de la thèse est de simplifier l'adoption du cloud et la migration vers ses environnements et technologies. Notre objectif est de proposer des solutions d'interopérabilité et de fédération dans le Cloud. Le travail de recherche s’est aussi articulé autour de deux grands axes. Le premier concerne le rapprochement des réseaux du futur et des Clouds. Le deuxième axe concerne l'interopérabilité et la fédération entre solutions et services cloud. Une analyse de l’état de l’art sur le Cloud Computing et le Cloud Networking, a permis de confirmer des manques pressentis et de proposer deux architectures de fédération Cloud. La première architecture permet le rapprochement entre le Cloud Computing et le Cloud Networking. La seconde architecture facilite l'interopérabilité et le courtage de services Cloud. L'étude des deux architectures a fait ressortir deux composants primordiaux et essentiels pour assurer la fédération: une interface générique et un système d'échange de messages. Ces deux composants correspondent à deux contributions centrales de la thèse et reflètent l’ensemble des contributions (quatre au total) du travail de recherchePresented in the literature as a new technology, Cloud Computing has become essential in the development and delivery of IT services. Given the innovative potential of Cloud, our thesis was conducted in the context of this promising technology. It was clear that the Cloud would change the way we develop, manage and use information systems. However, the adoption and popularization of Cloud were slow and difficult given the youth of the concepts and heterogeneity of the existing solutions. This difficulty in adoption is reflected by the lack of standard, the presence of heterogeneous architectures and APIs, the introduction of Vendor Lock-In imposed by the market leaders and the lack of cloud federation principles and facilitators. The main motivation for our PhD is to simplify the adoption of the cloud paradigm and the migration to cloud environments and technologies. Our goal has consequently been to improve interoperability and enable federation in the cloud. The thesis focused on two main areas. The first concerns the convergence of future networks and clouds and the second the improvement of federation and interoperability between heterogeneous cloud solutions and services. Based on our work in state of the art about Cloud Computing and Cloud Networking, we defined in this thesis two architectures for Cloud federation. The first architecture enables the merging (convergence) of Cloud Computing and Cloud Networking. The second architecture addresses interoperability between services and proposes cloud-brokering solutions. The study enabled the identification of two essential components for cloud federation, namely: a generic interface and a message exchange system. These two components have been two contributions of our thesis. The proposed federation architectures and these two components summarize the four major contributions of our work
36
Medhioub, Houssem. "Architectures et mécanismes de fédération dans les environnements cloud computing et cloud networking." Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2015. http://www.theses.fr/2015TELE0009.
Abstract:
Présenté dans la littérature comme une nouvelle technologie, le Cloud Computing est devenu incontournable dans la mise en place et la fourniture des services informatiques. Cette thèse s’inscrit dans le contexte de cette nouvelle technologie qui est en mesure de transformer la mise en place, la gestion et l’utilisation des systèmes d’information. L'adoption et la vulgarisation du Cloud ont été ralenties par la jeunesse même des concepts et l'hétérogénéité des solutions existantes. Cette difficulté d'adoption se manifeste par l'absence de standard, l'hétérogénéité des architectures et des API, le Vendor Lock-In imposé par les leaders du marché et des manques qui ralentissent la fédération. La motivation principale de la thèse est de simplifier l'adoption du cloud et la migration vers ses environnements et technologies. Notre objectif est de proposer des solutions d'interopérabilité et de fédération dans le Cloud. Le travail de recherche s’est aussi articulé autour de deux grands axes. Le premier concerne le rapprochement des réseaux du futur et des Clouds. Le deuxième axe concerne l'interopérabilité et la fédération entre solutions et services cloud. Une analyse de l’état de l’art sur le Cloud Computing et le Cloud Networking, a permis de confirmer des manques pressentis et de proposer deux architectures de fédération Cloud. La première architecture permet le rapprochement entre le Cloud Computing et le Cloud Networking. La seconde architecture facilite l'interopérabilité et le courtage de services Cloud. L'étude des deux architectures a fait ressortir deux composants primordiaux et essentiels pour assurer la fédération: une interface générique et un système d'échange de messages. Ces deux composants correspondent à deux contributions centrales de la thèse et reflètent l’ensemble des contributions (quatre au total) du travail de recherchePresented in the literature as a new technology, Cloud Computing has become essential in the development and delivery of IT services. Given the innovative potential of Cloud, our thesis was conducted in the context of this promising technology. It was clear that the Cloud would change the way we develop, manage and use information systems. However, the adoption and popularization of Cloud were slow and difficult given the youth of the concepts and heterogeneity of the existing solutions. This difficulty in adoption is reflected by the lack of standard, the presence of heterogeneous architectures and APIs, the introduction of Vendor Lock-In imposed by the market leaders and the lack of cloud federation principles and facilitators. The main motivation for our PhD is to simplify the adoption of the cloud paradigm and the migration to cloud environments and technologies. Our goal has consequently been to improve interoperability and enable federation in the cloud. The thesis focused on two main areas. The first concerns the convergence of future networks and clouds and the second the improvement of federation and interoperability between heterogeneous cloud solutions and services. Based on our work in state of the art about Cloud Computing and Cloud Networking, we defined in this thesis two architectures for Cloud federation. The first architecture enables the merging (convergence) of Cloud Computing and Cloud Networking. The second architecture addresses interoperability between services and proposes cloud-brokering solutions. The study enabled the identification of two essential components for cloud federation, namely: a generic interface and a message exchange system. These two components have been two contributions of our thesis. The proposed federation architectures and these two components summarize the four major contributions of our work
37
Opara-Martins, Justice. "A decision framework to mitigate vendor lock-in risks in cloud (SaaS category) migration." Thesis, Bournemouth University, 2017. http://eprints.bournemouth.ac.uk/29907/.
Abstract:
Cloud computing offers an innovative business model to enterprise IT services consumption and delivery. However, vendor lock-in is recognised as being a major barrier to the adoption of cloud computing, due to lack of standardisation. So far, current solutions and efforts tackling the vendor lock-in problem have been confined to/or are predominantly technology-oriented. Limited studies exist to analyse and highlight the complexity of vendor lock-in problem existing in the cloud environment. Consequently, customers are unaware of proprietary standards which inhibit interoperability and portability of applications when taking services from vendors. The complexity of the service offerings makes it imperative for businesses to use a clear and well understood decision process to procure, migrate and/or discontinue cloud services. To date, the expertise and technological solutions to simplify such transition and facilitate good decision making to avoid lock-in risks in the cloud are limited. Besides, little research investigations have been carried out to provide a cloud migration decision framework to assist enterprises to avoid lock-in risks when implementing cloud-based Software-as-a-Service (SaaS) solutions within existing environments. Such decision framework is important to reduce complexity and variations in implementation patterns on the cloud provider side, while at the same time minimizing potential switching cost for enterprises by resolving integration issues with existing IT infrastructures. Thus, the purpose of this thesis is to propose a decision framework to mitigate vendor lock-in risks in cloud (SaaS) migration. The framework follows a systematic literature review and analysis to present research findings containing factual and objective information, and business requirements for vendor-neutral interoperable cloud services, and/or when making architectural decisions for secure cloud migration and integration. The underlying research procedure for this thesis investigation consists of a survey based on qualitative and quantitative approaches conducted to identify the main risk factors that give rise to cloud computing lock-in situations. Epistemologically, the research design consists of two distinct phases. In phase 1, qualitative data were collected using open-ended interviews with IT practitioners to explore the business-related issues of vendor lock-in affecting cloud adoption. Whereas the goal of phase 2 was to identify and evaluate the risks and opportunities of lock-in which affect stakeholders’ decision-making about migrating to cloud-based solutions. In synthesis, the survey analysis and the framework proposed by this research (through its step-by-step approach), provides guidance on how enterprises can avoid being locked to individual cloud service providers. This reduces the risk of dependency on a cloud provider for service provision, especially if data portability, as the most fundamental aspect, is not enabled. Moreover, it also ensures appropriate pre-planning and due diligence so that the correct cloud service provider(s) with the most acceptable risks to vendor lock-in is chosen, and that the impact on the business is properly understood (upfront), managed (iteratively), and controlled (periodically). Each decision step within the framework prepares the way for the subsequent step, which supports a company to gather the correct information to make a right decision before proceeding to the next step. The reason for such an approach is to support an organisation with its planning and adaptation of the services to suit the business requirements and objectives. Furthermore, several strategies are proposed on how to avoid and mitigate lock-in risks when migrating to cloud computing. The strategies relate to contract, selection of vendors that support standardised formats and protocols regarding data structures and APIs, negotiating cloud service agreements (SLA) accordingly as well as developing awareness of commonalities and dependencies among cloud-based solutions. The implementation of proposed strategies and supporting framework has a great potential to reduce the risks of vendor lock-in.
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Carreño, Emmanuell Diaz. "Migration and evaluation of a numerical weather prediction application in a cloud computing infrastructure." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/127446.
Abstract:
O uso de clusters e grids tem beneficiado durante anos a comunidade de computação de alto desempenho (HPC). O uso deste tipo de sistemas tem permitido aos cientistas usar conjuntos de dados maiores para executar cálculos mais complexos. A computação de alto desempenho tem ajudado para obter aqueles resultados em menos tempo, mas aumentou o custo das despesas de capital nesta área da ciência. Como alguns projetos de e-science são realizados também em ambientes de rede altamente distribuídos, ou usando conjuntos de dados imensos que muitas vezes requerem computação em grade, eles são muito bons candidatos para as iniciativas de computação em nuvem. O paradigma Cloud Computing surgiu como uma solução prática com foco comercial para realizar computação científica em larga escala. A elasticidade da nuvem e o modelo pay-as-you-go apresenta uma oportunidade interessante para aplicações comumente executados em supercomputadores ou clusters. Esta tese apresenta e avalia os desafios da migração e execução da previsão numérica de tempo (NWP) numa infra-estrutura de computação em nuvem. Foi realizada a migração desta aplicação HPC e foi avaliado o desempenho em um cluster local e na nuvem utilizando diferentes tamanhos de instâncias virtuais. Analisamos as principais características da aplicação executando na nuvem. As experiências demonstram que, embora o processamento e a rede criam um fator limitante, o armazenamento dos conjuntos de dados de entrada e saída na nuvem apresentam uma opção atraente para compartilhar resultados e facilitar a implantação de um ambiente de ensaio para investigação meteorológica. Os resultados mostram que a infraestrutura de nuvem pode ser usada como uma alternativa viável de HPC para software de previsão numérica do tempo.The usage of clusters and grids has benefited for years the High Performance Computing (HPC) community. These kind of systems have allowed scientists to use bigger datasets and to perform more intensive computations, helping them to achieve results in less time but has also increased the upfront costs associated with this area of science. As some e-Science projects are carried out also in highly distributed network environments or using immense data sets that sometimes require grid computing, they are good candidates for cloud computing initiatives. The Cloud Computing paradigm has emerged as a practical solution to perform large-scale scientific computing. The elasticity of the cloud and its pay-as-you-go model presents an attractive opportunity for applications commonly executed in clusters or supercomputers. In this context, the user does not need to buy infrastructure, the resources can be rented from a provider and used for a period of time. This thesis presents the challenges and solutions of migrating a numerical weather prediction (NWP) application to a cloud computing infrastructure. We performed the migration of this HPC application and evaluated its performance in a local cluster and the cloud using different instance sizes. We analyzed the main characteristics of the application running in the cloud. The experiments demonstrate that, although processing and networking create a limiting factor, storing input and output datasets in the cloud presents an attractive option to share results and ease the deployment of a test-bed for a weather research platform. Results show that cloud infrastructure can be used as a viable HPC alternative for numerical weather prediction software.
39
Aslam, Mudassar. "Secure Service Provisioning in a Public Cloud." Licentiate thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-15243.
Abstract:
The evolution of cloud technologies which allows the provisioning of IT resources over the Internet promises many benefits for the individuals and enterprises alike. However, this new resource provisioning model comes with the security challenges which did not exist in the traditional resource procurement mechanisms. We focus on the possible security concerns of a cloud user (e.g. an organization, government department, etc.) to lease cloud services such as resources in the form of Virtual Machines (VM) from a public Infrastructure-as-a-Service (IaaS) provider. There are many security critical areas in the cloud systems, such as data confidentiality, resource integrity, service compliance, security audits etc. In this thesis, we focus on the security aspects which result in the trust deficit among the cloud stakeholders and hence hinder a security sensitive user to benefit from the opportunities offered by the cloud computing. Based upon our findings from the security requirements analysis,we propose solutions that enable user trust in the public IaaS clouds. Our solutions mainly deal with the secure life cycle management of the user VM which include mechanisms for VM launch and migration. The VM launch and migration solutions ensure that the user VM is always protected in the cloud by only allowing it to run on the user trusted platforms. This is done by using trusted computing techniques that allow the users to remotely attest and hence rate the cloud platforms trusted or untrusted. We also provide a prototype implementation to prove the implementation feasibility of the proposed trust enabling principles used in the VM launch and migration solutions.
40
Refaat, Tarek. "Virtual Machine Management for Dynamic Vehicular Clouds." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35864.
Abstract:
Vehicular clouds involve a dynamic environment where virtual machines are hosted on moving vehicles, leading to frequent changes in the data center network topology. These frequent topological changes require frequent virtual machine migrations in order to meet the service level agreements with cloud users. Such topology changes include fluctuations in connectivity, signal strength and quality. Few studies address vehicles as potential virtual machine hosts, while there is a significant opportunity in capitalizing on underutilized resources. Due to the rapidly changing environment of a vehicular cloud, hosts frequently change or leave coverage. As such, virtual machine management and migration schemes are necessary to ensure cloud subscribers have a satisfactory level of access to the resources. This thesis addresses the need for virtual machine management for the vehicular cloud. First, a mobility model is proposed and utilized to test a set of novel Vehicular Virtual Machine Migration (VVMM) schemes: VVMM-U (Uniform), VVMM-LW (Least Workload), VVMM-MA (Mobility Aware) and MDWLAM (Mobility and Destination Workload Aware Migration). Their performance is evaluated with respect to a set of metrics through simulations with varying levels of vehicular traffic congestion, virtual machine sizes and load restriction levels. The most advanced scheme (MDWLAM) takes into account the workload and mobility of the original host as well as those of the potential destinations. By doing so a valid destination will both have time to receive the workload and migrate the new load when necessary. The behavior of various algorithms is compared and the MDWLAM has been shown to demonstrate the best performance, exhibiting migration drop rates that are negligibly small. Finally, an integer linear program formulation based on a modified single source shortest path problem is presented, tested and successfully shown to be a benchmark that can be used in comparison to the proposed heuristics.
41
Alharthi, Abdulrahman Ayad. "A critical success factors assessment instrument for cloud migration readiness status in Saudi Arabian universities." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/419480/.
Abstract:
Saudi universities have at their disposal a huge number of low cost IT resources to aid teaching, research and learning. The emergence of cloud computing delivers substantial benefits in the form of rich education content, increased efficiency and agility that can be used to transform higher education in Saudi universities. By migrating to cloud services, Saudi universities will be moving data and programs from local servers to the internet, thereby providing users with the ability to access and share information at any time from multiple devices. Also, procuring IT resources such as infrastructure, applications, and platforms via the Internet will be cost effective, easy and fast. This will promote innovation in universities, as the main barrier of cost will be removed. However, the migration to cloud-based IT resources is not yet widespread in Saudi universities due to several challenges including security, legal policies and IT personnel skills. Moreover, at present, there is a lack of research and guidance on the significance of the Critical Success Factors (CSFs) to improve the success of cloud migration projects in Saudi university. These CSFs were used to measure the readiness of Saudi universities in terms of their ability, perception and readiness in making their cloud migration more successful. This research proposes a framework of enablers to guide the Saudi Arabian universities to migrate to the cloud paradigm successfully. In the presented research, a set of key CSFs was identified by synthesising factors from studies concerned with the migration of cloud for higher education in global context and factors identified from previous research investigating the successful implementation of Web Based Learning (WBL) and Enterprise Resource Planning (ERP) on higher education in Saudi Arabia. Based on the literature review, the proposed Success Factor Cloud Migration (SFCM1) framework was then evaluated via expert reviews and a survey conducted by IT specialists working in Saudi universities. The initial CSFs in SFCM1 were updated based on the expert reviews and the results were analysed via the Thematic Analysis approach. Based on the findings at this stage, additional CSFs were added to the framework as suggested by the experts. Subsequently, in order to confirm the reviewed CSFs, additional investigation via a structured online questionnaire was conducted and the outcome was analysed via one-sample t-test with the data integrity analysed via Cronbach’s alpha. The outcome indicated that most CSFs were statistically significant, apart from, the Physical Location CSF. Subsequently, based on the confirmed SFCM2 framework, a cloud migration readiness assessment instrument (CMRA) was developed using Goal Question Metrics (GQM) approach. The scoring scales of the CMRA instrument were adapted from the COBIT5 Process Assessment Model (PAM). The practicality of CMRA instrument was evaluated by three case studies conducted in Saudi universities. The instrument was used to assess the readiness status of the Saudi universities that already planned to migrate to the cloud. Afterwards, the usefulness and practicality of the CMRA were evaluated through an evaluation questionnaire and interviews with seniors working in IT deanships in Saudi universities. The contributions of this research are first that it developed a SFCM2 framework within the context of Saudi Arabian universities. Secondly, the framework was extended to an instrument (CMRA) to measure the readiness status of a particular Saudi university.
42
Castagnoli, Carlo. "Cloud Computing: gli Hypervisor e la funzionalità di Live Migration nelle Infrastructure as a Service." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/1856/.
43
Tixier, René. "Mystique et pédagogie dans "The Cloud of unknowing"." Nancy 2, 1988. http://www.theses.fr/1988NAN21013.
Abstract:
The cloud of unknowing, texte anonyme anglais ascétique et mystique du 14ème siècle, appartient à la tradition chrétienne de la lettre de direction spirituelle. A travers la relation qu'il entretient avec son dirigé, le directeur stimule ce dernier à l'effort anagogique, le renseigne sur l'objectif à atteindre -- l'union à Dieu -- ainsi que sur les moyens d'y parvenir. Ce-faisant, le maitre s'efface devant le maitre -- le christ enseignant -- permettant ainsi à la relation pédagogique qui unit deux hommes de fonctionner. A cet effacement du maitre correspond l'effacement de l'auteur devant son texte, lequel est fait pour travailler et faire travailler. Il apparaitra que cette loi d'effacement, caractéristique de toute écriture mystique, est régie par l'amour. D'autre part, l'utilisation pédagogique d'un certain nombre de techniques de la rhétorique médiévale (parallélismes, oppositions, accumulations, répétitions, allitérations, etc. ) n'empêche pas l'auteur de se tenir dans une indétermination fondamentale et "fonctionnelle" qui affecte l'ensemble de son texte. Bien plus, cette indétermination est imposée par la nature même du sujet traite: la recherche de la perfection par l'union d'amour à Dieu, dans la contemplation. Elle est rattachée à la tradition dionysienne apophatique de la "connaissance par inconnaissanceThe cloud of unknowing is an anonymous 14th-century english mystical and ascetical text belonging to the christian tradition of the letter of spiritual direction. In this text the spiritual director stimulates his "disciple" in his anagogical effort, while teaching him the goal to be reached (man's loving union to god) as well as the means to be used. Meanwhile, the director endeavours to withdraw and leave his disciple in the presence of christ the teacher, thus making it possible for the pedagogical relationship between two men to "work". This withdrawal of the director corresponds to the author's withdrawal from his text -- a text meant to "work" and to make the disciple work. This "law of withdrawal", which is characteristic of mystical writing, will prove to be ruled by love. On the other hand, the use of number of medieval rhetorical techniques (parallelisms, oppositions, accumulations, repetitions, alliterations, etc. ) Will not prevent the author from remaining in a form of fundamental as well as "functional" indetermination which will affect his whole text
44
Ewelle, Ewelle Richard. "Adapter les communications des jeux dans le cloud." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS145/document.
Abstract:
Le Cloud computing émerge comme le nouveau paradigme informatique dans lequel la virtualisation des ressources fournit des services fiables correspondant aux demandes des utilisateurs. De nos jours, la plupart des applications interactives et utilisant beaucoup de données sont développées sur le cloud: Le jeu vidéo en est un exemple. Avec l'arrivée du cloud computing, l'accessibilité et l'ubiquité du jeu ont un brillant avenir; Les jeux peuvent être hébergés dans un serveur centralisé et accessibles via l'Internet par un client léger sur une grande variété de dispositifs avec des capacités modestes : c'est le cloud gaming. Le Cloud computing, dans le contexte de jeu vidéo a beaucoup attiré l'attention en raison de ses facilités d'évolution, de disponibilité et capacité de calcul. Cependant, les systèmes de cloud gaming actuels ont des exigences très fortes en termes de ressources réseau, réduisant ainsi l'accessibilité et l'ubiquité des jeux dans le cloud, car les dispositifs clients avec peu de bande passante et les personnes situées dans la zone avec des conditions de réseau limitées et/ou instables, ne peuvent pas bénéficier de ces services de cloud computing. Dans cette thèse, nous présentons une technique d'adaptation inspirée par l'approche du niveau de détail (Level of detail) dans les graphiques 3D. Elle est basée sur un paradigme du cloud gaming dans l'objectif de fournir une accessibilité multi-plateforme, tout en améliorant la qualité d'expérience (QoE) du joueur en réduisant l'impact des mauvaises conditions réseau (delai, perte, gigue) sur l'interactivité et réactivité du jeu. Notre première contribution se compose de modèles de jeu reliant les objets du jeu à leurs besoins en termes de communication représentés par leurs importances dans le jeu. Nous avons ensuite fourni une approche de niveau de détail pour gérer la distribution des ressources réseau basée sur l'importance des objets dans la scène et les conditions réseau. Nous validons notre approche en utilisant des jeu prototypes et evaluons la QoE du joueur, par des expériences pilotes. Les résultats montrent que le framework proposé fournit une importante amélioration de la QoEWith the arrival of cloud computing technology, game accessibility and ubiquity havea bright future. Games can be hosted in a centralize server and accessed through theInternet by a thin client on a wide variety of devices with modest capabilities: cloudgaming. Some of the advantages of using cloud computing in game context includes:device ubiquity, computing exibility, affordable cost and lowered set up overheads andcompatibility issues. However, current cloud gaming systems have very strong requirementsin terms of network resources, thus reducing their widespread adoption. In factdevices with little bandwidth and people located in area with limited network capacity,cannot take advantage of these cloud services. In this thesis we present an adaptationtechnique inspired by the level of detail (LoD) approach in 3D graphics. It is based ona cloud gaming paradigm in other to maintain user's quality of experience (QoE) byreducing the impact of poor network parameters (delay, loss, bandwidth) on game interactivity.Our first contribution consist of game models expressing game objects and theircommunications needs represented by their importance in the game. We provided twodifferent ways to manage objects' importance using agents organizations and gameplaycomponents. We then provided a level of detail approach for managing network resourcedistribution based on objects importance in the game scene and network conditions. Weexploited the dynamic objects importance adjustment models presented above to proposeLoD systems adapting to changes during game sessions. The experimental validation ofboth adaptation models showed that the suggested adaptation minimizes the effects oflow and/or unstable network conditions in maintaining game responsiveness and player'sQoE
45
Liu, Ji. "Gestion multisite de workflows scientifiques dans le cloud." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT260/document.
Abstract:
Les in silico expérimentations scientifiques à grande échelle contiennent généralement plusieurs activités de calcule pour traiter big data. Workflows scientifiques (SWfs) permettent aux scientifiques de modéliser les activités de traitement de données. Puisque les SWfs moulinent grandes quantités de données, les SWfs orientés données deviennent un problème important. Dans un SWf orienté donnée, les activités sont liées par des dépendances de données ou de contrôle et une activité correspond à plusieurs tâches pour traiter les différentes parties de données. Afin d’exécuter automatiquement les SWfs orientés données, Système de management pour workflows scientifiques (SWfMSs) peut être utilisé en exploitant High Perfmance Comuting (HPC) fournisse par un cluster, grille ou cloud. En outre, SWfMSs génèrent des données de provenance pour tracer l’exécution des SWfs.Puisque le cloud fournit des services stables, diverses ressources, la capacité de calcul et de stockage virtuellement infinie, il devient une infrastructure intéressante pour l’exécution de SWf. Le cloud données essentiellement trois types de services, i.e. Infrastructure en tant que Service (IaaS), Plateforme en tant que Service (PaaS) et Logiciel en tant que Service (SaaS). SWfMSs peuvent être déployés dans le cloud en utilisant des Machines Virtuelles (VMs) pour exécuter les SWfs orientés données. Avec la méthode de pay-as-you-go, les utilisateurs de cloud n’ont pas besoin d’acheter des machines physiques et la maintenance des machines sont assurée par les fournisseurs de cloud. Actuellement, le cloud généralement se compose de plusieurs sites (ou centres de données), chacun avec ses propres ressources et données. Du fait qu’un SWf orienté donnée peut-être traite les données distribuées dans différents sites, l’exécution de SWf orienté donnée doit être adaptée aux multisite cloud en utilisant des ressources de calcul et de stockage distribuées.Dans cette thèse, nous étudions les méthodes pour exécuter SWfs orientés données dans un environnement de multisite cloud. Certains SWfMSs existent déjà alors que la plupart d’entre eux sont conçus pour des grappes d’ordinateurs, grille ou cloud d’un site. En outre, les approches existantes sont limitées aux ressources de calcul statique ou à l’exécution d’un seul site. Nous vous proposons des algorithmes pour partitionner SWfs et d’un algorithme d’ordonnancement des tâches pour l’exécution des SWfs dans un multisite cloud. Nos algorithmes proposés peuvent réduire considérablement le temps global d’exécution d’un SWf dans un multisite cloud.En particulier, nous proposons une solution générale basée sur l’ordonnancement multi-objectif afin d’exécuter SWfs dans un multisite cloud. La solution se compose d’un modèle de coût, un algorithme de provisionnement de VMs et un algorithme d’ordonnancement des activités. L’algorithme de provisionnement de VMs est basé sur notre modèle de coût pour générer les plans à provisionner VMs pour exécuter SWfs dans un cloud d’un site. L’algorithme d’ordonnancement des activités permet l’exécution de SWf avec le coût minimum, composé de temps d’exécution et le coût monétaire, dans un multisite cloud. Nous avons effectué beaucoup d’expérimentations et les résultats montrent que nos algorithmes peuvent réduire considérablement le coût global pour l’exécution de SWf dans un multisite cloudLarge-scale in silico scientific experiments generally contain multiple computational activities to process big data. Scientific Workflows (SWfs) enable scientists to model the data processing activities. Since SWfs deal with large amounts of data, data-intensive SWfs is an important issue. In a data-intensive SWf, the activities are related by data or control dependencies and one activity may consist of multiple tasks to process different parts of experimental data. In order to automatically execute data-intensive SWfs, Scientific Work- flow Management Systems (SWfMSs) can be used to exploit High Performance Computing (HPC) environments provided by a cluster, grid or cloud. In addition, SWfMSs generate provenance data for tracing the execution of SWfs.Since a cloud offers stable services, diverse resources, virtually infinite computing and storage capacity, it becomes an interesting infrastructure for SWf execution. Clouds basically provide three types of services, i.e. Infrastructure-as-a-Service (IaaS), Platform- as-a-Service (PaaS) and Software-as-a-Service (SaaS). SWfMSs can be deployed in the cloud using Virtual Machines (VMs) to execute data-intensive SWfs. With a pay-as-you- go method, the users of clouds do not need to buy physical machines and the maintenance of the machines are ensured by the cloud providers. Nowadays, a cloud is typically made of several sites (or data centers), each with its own resources and data. Since a data- intensive SWf may process distributed data at different sites, the SWf execution should be adapted to multisite clouds while using distributed computing or storage resources.In this thesis, we study the methods to execute data-intensive SWfs in a multisite cloud environment. Some SWfMSs already exist while most of them are designed for computer clusters, grid or single cloud site. In addition, the existing approaches are limited to static computing resources or single site execution. We propose SWf partitioning algorithms and a task scheduling algorithm for SWf execution in a multisite cloud. Our proposed algorithms can significantly reduce the overall SWf execution time in a multisite cloud.In particular, we propose a general solution based on multi-objective scheduling in order to execute SWfs in a multisite cloud. The general solution is composed of a cost model, a VM provisioning algorithm, and an activity scheduling algorithm. The VM provisioning algorithm is based on our proposed cost model to generate VM provisioning plans to execute SWfs at a single cloud site. The activity scheduling algorithm enables SWf execution with the minimum cost, composed of execution time and monetary cost, in a multisite cloud. We made extensive experiments and the results show that our algorithms can reduce considerably the overall cost of the SWf execution in a multisite cloud
46
Tran, van Paul. "Partage de documents sécurisé dans le Cloud Personnel." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV015/document.
Abstract:
Ces dernières années ont été marquées par une numérisation croissante de nos vies, conjuguée à une explosion du volume des données personnelles sur Internet. Cela a favorisé l’émergence d’un marché focalisé sur leur analyse, afin d’établir des profils de plus en plus poussés et intrusifs des individus, généralement à leur insu. Parallèlement, des surveillances d’états se mettent en place qui font craindre un glissement progressif vers des dystopies jusqu’ici réservées à la littérature. Afin de répondre à cette situation, le paradigme du Cloud personnel s’est développé : chaque utilisateur a désormais la possibilité de stocker et gérer l’intégralité de son patrimoine numérique dans un unique espace de confiance dont il est le seul responsable.Cette responsabilisation entraîne cependant un changement de gouvernance sur les données, dont la sécurité et l’administration reposent désormais sur les épaules des individus. En particulier lorsqu’ils souhaitent partager leurs documents et donc les exposer à des personnes ou services tiers. Cette thèse propose ainsi un nouveau paradigme dans la façon de partager dans le Cloud personnel qui met l’accent sur la sécurité, mais aussi sur le contrôle et la simplicité d’utilisation par les individus. Trois contributions sont faites en ce sens : (i) une architecture Privacy-by-Design, dédiée au Cloud personnel, (ii) un modèle de partage adapté aux propriétés du Cloud personnel et (iii) un protocole de partage implémenté dans la plateforme CozyThese past years have witnessed a growing digitalization of our lives, combined with an explosion of personal data quantity on the Internet. This has opened the way to a data-driven market focused on their analysis for profiling purposes, increasingly intrusive and most of the time performed without the user acknowledgement. At the same time, states surveillances are being established, raising concerns about potential dystopias, until now confined in the literature. To tackle this situation, the Personal Cloud paradigm has risen: each user has now the possibility to store and manage all her digital life in a trusted space in which she is the sole responsible.However, this empowerment leads to a governance switch. The user is now in charge of the security and the administration of their data. In particular in the sharing context, where the data is exposed to people or third-parties. Therefore, this thesis proposes a new paradigm in the way the sharing is performed in the Personal Cloud. It focuses on security, control and on a better simplicity of use for the users. Three contributions are made in this direction: (i) a Privacy-by-Design architecture, dedicated for the Personal Cloud context, (ii) a sharing model suited for the Personal Cloud properties and (iii) a sharing protocol implemented in the Cozy platform
47
Del, Piccolo Valentin. "Isolation réseau dans un environnement Cloud Public/Hybride." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066050/document.
Abstract:
Le cloud computing est un modèle informatique donnant accès à un grand nombre de ressources de calcul et de stockage. Trois types de cloud existent, le cloud public, le cloud privé et le cloud hybride. Afin de proposer une solution cloud hybride, nous utilisons le protocole TRILL qui permet d'optimiser l'utilisation des ressources réseau d'une infrastructure. Cependant, TRILL ne permet pas d'interconnecter des data centers sans perdre l'indépendance de leur plan de contrôle. Pour modifier ce comportement, lequel implique la création d'un unique domaine de broadcast s'étendant sur tout le réseau, nous proposons, comme première contribution, une solution (MLTP) qui permet d'interconnecter des réseaux TRILL tout en les maintenant indépendants. Un autre élément manquant de TRILL est l'isolation des flux réseau. Notre seconde contribution consiste donc à trouver et implémenter une solution d'isolation des flux au sein de MLTP. Ce nouveau protocole (MLTP+VNT), permet d'avoir une solution de cloud hybride, mais elle possède deux désavantages. Le premier est la gestion des pannes. Certains éléments de MLTP+VNT, les Border RBridges (BRB), contiennent des informations nécessaires au routage inter-data center et lorsqu'ils tombent en panne, ces informations sont perdues. Pour éviter cela, nous avons, dans notre troisième contribution, modifié MLTP+VNT pour synchroniser les BRBs. Le second est l'obligation de n'utiliser que des réseaux MLTP+VNT pour réaliser un cloud hybride. Pour lever cette restriction, nous avons, dans notre quatrième contribution, conçu une passerelle entre un réseau TRILL, pour le cloud public, et un réseau OpenFlow, pour le cloud privéCloud computing uses infrastructure with a lot of computing and storage resources. There are three types of cloud: Public cloud, Private cloud, and Hybrid cloud. In order to provide a hybrid cloud solution, we used as a base the TRILL protocol which optimizes the use of the data center infrastructure. However, TRILL cannot interconnect data centers as doing so will merge the data centers networks and each data center will lose its independence. Our first contribution is to change this behavior and we develop MLTP which allows to interconnect TRILL or MLTP network without merging them. Another functionality missing from TRILL is network isolation. To fill this lack, in our second proposal we add to MLTP a solution called VNT and we then have a new protocol called MLTP+VNT. In this protocol, each user traffic is isolated from one another. Therefore, MLTP+VNT allows to have a hybrid cloud environment. Nevertheless, it has two shortcomings. The first one is its “single” point of failure. As a matter of fact, MLTP+VNT uses a new type of nodes called Border RBridges which contains inter-data centers routing information. If a Border RBridge fails, then the information it contained is lost. In order to prevent this loss, we implement a method to synchronize the Border RBridges in our third contribution. The second shortcoming is the obligation to use MLTP+VNT in each network to form the hybrid cloud. To lift this limitation, we design and develop, in our fourth contribution, a bridge between a MLTP+VNT network and an OpenFlow network. This way, our solution allows to create a hybrid cloud environment with the MLTP+VNT solution in the public cloud and OpenFlow in the public cloud
48
Del, Piccolo Valentin. "Isolation réseau dans un environnement Cloud Public/Hybride." Electronic Thesis or Diss., Paris 6, 2017. http://www.theses.fr/2017PA066050.
Abstract:
Le cloud computing est un modèle informatique donnant accès à un grand nombre de ressources de calcul et de stockage. Trois types de cloud existent, le cloud public, le cloud privé et le cloud hybride. Afin de proposer une solution cloud hybride, nous utilisons le protocole TRILL qui permet d'optimiser l'utilisation des ressources réseau d'une infrastructure. Cependant, TRILL ne permet pas d'interconnecter des data centers sans perdre l'indépendance de leur plan de contrôle. Pour modifier ce comportement, lequel implique la création d'un unique domaine de broadcast s'étendant sur tout le réseau, nous proposons, comme première contribution, une solution (MLTP) qui permet d'interconnecter des réseaux TRILL tout en les maintenant indépendants. Un autre élément manquant de TRILL est l'isolation des flux réseau. Notre seconde contribution consiste donc à trouver et implémenter une solution d'isolation des flux au sein de MLTP. Ce nouveau protocole (MLTP+VNT), permet d'avoir une solution de cloud hybride, mais elle possède deux désavantages. Le premier est la gestion des pannes. Certains éléments de MLTP+VNT, les Border RBridges (BRB), contiennent des informations nécessaires au routage inter-data center et lorsqu'ils tombent en panne, ces informations sont perdues. Pour éviter cela, nous avons, dans notre troisième contribution, modifié MLTP+VNT pour synchroniser les BRBs. Le second est l'obligation de n'utiliser que des réseaux MLTP+VNT pour réaliser un cloud hybride. Pour lever cette restriction, nous avons, dans notre quatrième contribution, conçu une passerelle entre un réseau TRILL, pour le cloud public, et un réseau OpenFlow, pour le cloud privéCloud computing uses infrastructure with a lot of computing and storage resources. There are three types of cloud: Public cloud, Private cloud, and Hybrid cloud. In order to provide a hybrid cloud solution, we used as a base the TRILL protocol which optimizes the use of the data center infrastructure. However, TRILL cannot interconnect data centers as doing so will merge the data centers networks and each data center will lose its independence. Our first contribution is to change this behavior and we develop MLTP which allows to interconnect TRILL or MLTP network without merging them. Another functionality missing from TRILL is network isolation. To fill this lack, in our second proposal we add to MLTP a solution called VNT and we then have a new protocol called MLTP+VNT. In this protocol, each user traffic is isolated from one another. Therefore, MLTP+VNT allows to have a hybrid cloud environment. Nevertheless, it has two shortcomings. The first one is its “single” point of failure. As a matter of fact, MLTP+VNT uses a new type of nodes called Border RBridges which contains inter-data centers routing information. If a Border RBridge fails, then the information it contained is lost. In order to prevent this loss, we implement a method to synchronize the Border RBridges in our third contribution. The second shortcoming is the obligation to use MLTP+VNT in each network to form the hybrid cloud. To lift this limitation, we design and develop, in our fourth contribution, a bridge between a MLTP+VNT network and an OpenFlow network. This way, our solution allows to create a hybrid cloud environment with the MLTP+VNT solution in the public cloud and OpenFlow in the public cloud
49
Chaulet, Maxime. "Rôle du cil primaire dans la migration des neuroblastes du courant de migration rostrale." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS191.
Abstract:
L'objectif de ma thèse a été de mieux comprendre les mécanismes sous tendant le rôle du cil primaire (CP) dans la migration neuronale. Notre modèle d’étude est la migration dans le courant de migration rostrale (CMR) chez la souris post-natale et adulte. Les neurones du CMR présentent une migration saltatoire alternant pause et nucléokinèse avec un mouvement stéréotypé du centrosome. Dans une première étude, aux résultats encore préliminaires, nous avons comparé la migration entre la souris post-natale (P10) et jeune adulte (P30) par imagerie sur tranche aigüe de cerveau, ainsi que l'effet d'une ablation génétique du CP à ces deux âges. Nous observons que les migrations diffèrent entre les deux âges et que l'ablation génétique du CP affecte différentiellement les paramètres de migration. Dans une deuxième étude, bientôt soumise pour publication, nous avons analysé la dynamique de l’AMPc au cours de la migration postnatale. Nous avons observé la présence cyclique d’un hotspot d’AMPc au centrosome, sous le CP. Nous montrons que l’AMPc produit dans le cil diffuse au centrosome et active localement la Protéine Kinase A dépendante de l’AMPc (PKA). L’ablation génétique du CP et le knock-down de l’adénylate cyclase 3 ciliaire mènent à une disparition du hotspot. Ils affectent également la migration avec un défaut de couplage centrosome/noyau conduisant à une altération de la nucléokinèse, ce qui est récapitulé par la délocalisation génétique de la PKA. Nous montrons donc que le centrosome et le CP agissent comme une unité de signalisation unique liée par la diffusion de l'AMPc ciliaire, ce qui régule la rythmicité de la migration saltatoire au centrosomeThe aim of my thesis was to better understand the mechanisms underlying the role of the primary cilium (PC) in neuronal migration. Our study model is the tangential migration in the rostral migratory stream (RMS) in the postnatal and adult mice. Neuroblasts of the CMR show a saltatory migration with pause and nucleokinesis and a stereotyped centrosome movement. In a first study with preliminary results, we compared the migration between postnatal (P10) and young adult (P30) stages by live imaging on acute brain slices, as well as the effect of genetic ablation of the PC at these two ages. We showed that migrations are different between these two stages and that genetic ablation of the PC impaired differentially migration parameters. In a second study, submitted for publication soon, we analysed cAMP dynamics during postnatal migration. We observed a dynamic cAMP hotspot cyclically at the centrosome, at the basis of the PC. We show that ciliary-produced cAMP diffuses to the centrosome, where it activates locally the cAMP-dependent Protein Kinase A (PKA). Genetic ablation of the cilium and knock-down of the ciliary Adenylate Cyclase 3 lead to the hotspot disappearance. They also affect migration with defective centrosome/nucleus coupling leading to altered nucleokinesis, which is recapitulated by PKA genetic delocalization. We thus show that PC and centrosome act as a signalling unit, linked by ciliary cAMP diffusion regulating the rhythmicity of salutatory migration at the centrosome
50
Elrajeh, Dima, and Marwan Issaks. "Bekymmer och lösningar för att lagra data i moln." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-67248.
Abstract:
Syftet med denna tekniska rapport är att studera följande aspekter: ekonomiska, återanvändning av kod och tidsåtgång för att publicera osv till flera molntjänstleverantörer för att uppnå bättre redundans. Webapplikationen kommer att publiceras till Azure, Amazon Cloud och Google Cloud. Avhandlingen täcker de vanligaste problemen som företag kan stöta på när de ska migrera sin verksamhet till molnet. De interna och yttre hot som datakorruption, skadlig insider, osäker autentisering i API: er, beteendeavbrott, dataöverträdelser, fysiska skador på datacenter och befintliga lösningar diskuteras djupt för att skapa en bättre förståelse om molntjänster är säkra för datalagring. Det praktiska projektet genomfördes framgångsrikt i tid och möjliggjorde att författarna fick en tydlig bild av de hinder som kan uppstå vid överföring av en webbapplikation mellan olika molntjänster.The purpose of this technical report is to study the economical, code reusability and the required time for publishing a web application to multiple cloud service providers for achieving better redundancy. The web application will be published to Azure, Amazon cloud, and Google cloud. The thesis covers the most common concerns that companies have adapting cloud computing in their business. The internal and external threats such as data corruption, malicious insider, insecure authentication in APIs, denial of service attacks, data breaches, physical damage to data centers and existing solutions will be discussed in depth to create a better understanding if cloud computing is safe for data storing. The practical project was completed successfully in time and enabled the writers to give an educated description over the obstacles that were faced during the transfer of the web application between different clouds.