L’évolution et l’accroissement actuels des technologies amènent les entreprises à vouloir se développer plus rapidement afin de rester compétitives et offrir des services à la pointe de la technologie, répondant aux besoins du marché. En effet, les entreprises étant sujettes à des changements assez fréquents requièrent un haut niveau de flexibilité et d’agilité. La gestion des processus métiers (BPM) leur permet dans ce sens de mieux appréhender et gérer leurs processus. Par ailleurs, l’apparition du Cloud Computing et de tous ses bénéfices (flexibilité et partage, coût optimisé, accessibilité garantie...etc) le rendent particulièrement attrayant. Ainsi, l’association de ces deux concepts permet aux entreprises de renflouer leur capital. Cependant, l’utilisation du cloud implique également de nouvelles exigences en terme de sécurité, qui découlent de son environnement partagé, et qui mettent un frein à sa large adoption. Le travail de cette thèse consiste à proposer des concepts et outils pour aider et guider les entreprises dans le déploiement de leurs processus dans un environnement cloud en toute sécurité. Une première contribution est un algorithme d’obfuscation permettant d’automatiser la décomposition et le déploiement des processus sans intervention humaine, en se basant sur la nature des fragments. Cet algorithme limite le taux d’informations sur chaque cloud à travers un ensemble de contraintes de séparation, permettant de déployer les fragments considérés comme étant sensibles sur différents clouds. La seconde contribution de cette thèse consiste à complexifier la structure du processus afin de limiter le risque de coalition de clouds. Ceci se fait à travers l’introduction de faux fragments à certains endroits stratégiques du processus. L’objectif étant de rendre les collaborations générées plus résistantes aux attaques, et par conséquent de réduire la probabilité de coalition. Même si les opérations d’obfuscation et de complexification protègent le savoir-faire des entreprises lors d’un déploiement cloud, un risque subsiste toujours. Dans ce contexte, cette thèse propose également un modèle de risque permettant d’évaluer et de quantifier les risques de sécurité auxquels restent exposés les processus après déploiement. L’objectif de ce modèle est de combiner les informations de sécurité avec d’autres dimensions de la qualité de service tel que le coût, pour la sélection de configurations optimisées. Les approches proposées sont implémentées et testées à travers différentes configurations de processus. Leur validité est vérifiée à travers un ensemble de métriques dont l’objectif est de mesurer la complexité des processus après l’opération d’obfuscation ainsi que le niveau de risque subsistant / The fast evolution and development of technologies lead companies to grow faster in order to remain competitive and to offer services which are at the cutting edge of technology, meeting today’s market needs. Indeed, companies that are subject to frequent changes require a high level of flexibility and agility. Business Process Management (BPM) allows them to better manage their processes. Moreover, the emergence of Cloud Computing and all its advantages (flexibility and sharing, optimized cost, guaranteed accessibility... etc) make it particularly attractive. Thus, the combination of these two concepts allows companies to refloat their capital. However, the use of the cloud also implies new requirements in term of security, which stem from its shared environment, and which slow down its widespread adoption. The objective of this thesis consists in proposing concepts and tools that help and guide companies to deploy safely their processes in a cloud environment. A first contribution is an obfuscation algorithm that automates the decomposition and deployment of processes without any human intervention, based on the nature of the fragments. This algorithm limits the rate of information on each cloud through a set of separation constraints, which allow to deploy fragments considered as sensitive on different clouds. The second contribution of this thesis consists in complicating the structure of the process in order to limit the risk of clouds coalition. This is done through the introduction of fake fragments at certain strategic points in the process. The goal is to make generated collaborations more resistant to attacks, and thus reducing the likelihood of coalition. Even if obfuscation and complexification operations protect companies’ know-how during a cloud deployment, a risk remains. In this context, this thesis also proposes a risk model for evaluating and quantifying the security risks to which the process remain exposed after deployment. The purpose of this model is to combine security information with other dimensions of quality of service such as cost, for the selection of optimized configurations. The proposed approaches are implemented and tested through different process configurations. Their validity is verified through a set of metrics, whose objective is to measure the complexity of the processes as well as the remaining risk level after obfuscation

A Computação em Nuvem (CN) é um dos temas mais abordados por profissionais de TI atualmente. Com um forte apelo econômico, a CN torna possível a ideia da computação como uma utilidade, na qual recursos computacionais (processamento e armazenamento, por exemplo) podem ser consumidos e pagos com a mesma conveniência que a energia elétrica. Com este novo paradigma, uma empresa, ao iniciar suas atividades, não necessita mais investir antecipadamente um alto capital em equipamentos de TI. Os recursos computacionais são adquiridos conforme são necessários e o consumidor paga apenas pelo que utiliza. Esta pesquisa traz uma contribuição para as organizações e para o meio acadêmico, uma vez que analisa a adoção da CN por empresas brasileiras. A pesquisa abrange empresas privadas de diversos portes e setores que tenham adotado pelo menos um serviço de TI no modelo de CN. O modelo de pesquisa foi elaborado com base nos objetivos específicos, os quais se originaram das lacunas existentes sobre o uso de serviços de CN no Brasil. A pesquisa utilizou uma amostra não probabilística contendo 96 casos, os quais contemplaram aspectos do respondente, da organização e do serviço de CN mais importante para a organização. Os dados foram coletados por meio de um questionário e tratados estatisticamente usando técnicas não paramétricas e Análise de Agrupamentos. A pesquisa se caracteriza por ser exploratória, verificando frequências e ligações entre as características organizacionais e os serviços de CN. A pesquisa identificou as características dos serviços de CN utilizados no Brasil e o grau de aderência de cada serviço à definição de CN proposta. Adicionalmente, foram apresentadas as relações entre as características organizacionais e as características dos serviços de CN. Além disso, foi possível identificar três grupos distintos de empresas, em relação às características dos serviços de CN utilizados, e descrever às características organizacionais e dos serviços associados a cada grupo. Finalmente, a CN foi discutida à luz das Teorias de Terceirização. / Cloud Computing (CC) is one of the most discussed topics among IT professionals today. With a strong economic appeal, CC makes possible the idea of computing as a utility, in which computing resources (processing power and storage, for example) can be consumed and paid with the same convenience as electricity. In this new paradigm, a startup company does not need up-front capital to invest in advanced IT assets. The computing resources are acquired as needed and the customer pays only for what is used. This research makes an important contribution to organizations and academia, since it analyzes CC adoption by Brazilian companies. The survey covers private companies of all sizes and sectors that have adopted at least one IT service in CC model. The research model was designed based on the research specific objectives, which were made from the gaps of CC services usage in Brazil. This paper used a not randomly picked sample with 96 cases, which specified aspects of the respondent, organization and the most important CC service to the organization. Data was collected through a questionnaire and statistically analyzed using nonparametric techniques and Cluster Analysis. This research is characterized as exploratory, checking frequencies and links between organizational characteristics and CC services characteristics. This research identified the characteristics of CC services used in Brazil and the compliance degree of each service to the proposed CC definition. Additionally, we presented and discussed the relationships between organizational characteristics and characteristics of CC services. Furthermore, it was possible to identify three distinct groups of companies in relation to the characteristics of CC services they use, and describe organizational characteristics and services associated with each group. Finally, CC was discussed in the light of the Outsourcing Theories.

The thesis deals with the use of cloud computing to solve computationally intensive task. Simulation methods are employed to analyze the operation of the proposed system before putting it into operation. Cloud computing makes the functionality of modern data centers accessible to small businesses, cloud allows scaling up and scaling down of resource usage on an as-needed basis; moreover, without high initial investments and long-term commitments. The paper examines in detail the ways to adapt the currently most popular cloud environment of Amazon's Elastic Compute Cloud to the specific requirements of custom applications and suggests ways to automate the process of creation and customization of instance images. The automation and management of running applications in cloud environment is demonstrated on the example of geographic data processing and map generation application. The simulation model for running applications in the cloud is built and exploited to verify the ability of the proposed solutions to succeed in a production deployment.

Information technologies develop very quickly. And in the same way should be changed the companie's attitude to them. But the question is whether this is actually happening. If the companies and their employees are able to adapt to new technologies as quickly as these technologies arise. One of the phenomena of recent years is delivering applications through Software As A Service (SaaS). This concept is closely linked with the issue of Cloud computing and its use can be solved by outsourcing corporate IT structure. So here we meet three very exposed concepts. But their terms are often used confused or in the wrong context. This work focuses on explaining these concepts in the context of business intelligence and analysis on the aspects that affect them. In particular, cloud computing is a modern concept, which everyone talks about but only few people know exactly what it means and what it could bring to a particular company. This work helps to answer these questions and it helps to sort out the context and framework within which the possible changes in the corporate IT infrastructure should be discussed to make decisions. The first part is focused on basic lighting of these concepts and their insertion into mutual context. The second part is then devoted to current trends in this area so that conclusions for a prediction of the expected development in the coming years can be drawn.

A Computação em Nuvem (CN) é um dos temas mais abordados por profissionais de TI atualmente. Com um forte apelo econômico, a CN torna possível a ideia da computação como uma utilidade, na qual recursos computacionais (processamento e armazenamento, por exemplo) podem ser consumidos e pagos com a mesma conveniência que a energia elétrica. Com este novo paradigma, uma empresa, ao iniciar suas atividades, não necessita mais investir antecipadamente um alto capital em equipamentos de TI. Os recursos computacionais são adquiridos conforme são necessários e o consumidor paga apenas pelo que utiliza. Esta pesquisa traz uma contribuição para as organizações e para o meio acadêmico, uma vez que analisa a adoção da CN por empresas brasileiras. A pesquisa abrange empresas privadas de diversos portes e setores que tenham adotado pelo menos um serviço de TI no modelo de CN. O modelo de pesquisa foi elaborado com base nos objetivos específicos, os quais se originaram das lacunas existentes sobre o uso de serviços de CN no Brasil. A pesquisa utilizou uma amostra não probabilística contendo 96 casos, os quais contemplaram aspectos do respondente, da organização e do serviço de CN mais importante para a organização. Os dados foram coletados por meio de um questionário e tratados estatisticamente usando técnicas não paramétricas e Análise de Agrupamentos. A pesquisa se caracteriza por ser exploratória, verificando frequências e ligações entre as características organizacionais e os serviços de CN. A pesquisa identificou as características dos serviços de CN utilizados no Brasil e o grau de aderência de cada serviço à definição de CN proposta. Adicionalmente, foram apresentadas as relações entre as características organizacionais e as características dos serviços de CN. Além disso, foi possível identificar três grupos distintos de empresas, em relação às características dos serviços de CN utilizados, e descrever às características organizacionais e dos serviços associados a cada grupo. Finalmente, a CN foi discutida à luz das Teorias de Terceirização. / Cloud Computing (CC) is one of the most discussed topics among IT professionals today. With a strong economic appeal, CC makes possible the idea of computing as a utility, in which computing resources (processing power and storage, for example) can be consumed and paid with the same convenience as electricity. In this new paradigm, a startup company does not need up-front capital to invest in advanced IT assets. The computing resources are acquired as needed and the customer pays only for what is used. This research makes an important contribution to organizations and academia, since it analyzes CC adoption by Brazilian companies. The survey covers private companies of all sizes and sectors that have adopted at least one IT service in CC model. The research model was designed based on the research specific objectives, which were made from the gaps of CC services usage in Brazil. This paper used a not randomly picked sample with 96 cases, which specified aspects of the respondent, organization and the most important CC service to the organization. Data was collected through a questionnaire and statistically analyzed using nonparametric techniques and Cluster Analysis. This research is characterized as exploratory, checking frequencies and links between organizational characteristics and CC services characteristics. This research identified the characteristics of CC services used in Brazil and the compliance degree of each service to the proposed CC definition. Additionally, we presented and discussed the relationships between organizational characteristics and characteristics of CC services. Furthermore, it was possible to identify three distinct groups of companies in relation to the characteristics of CC services they use, and describe organizational characteristics and services associated with each group. Finally, CC was discussed in the light of the Outsourcing Theories.

Le Cloud Computing est un paradigme émergent dans les technologies de l'information. L'un de ses atouts majeurs étant la mise à disposition des ressources fondée sur le modèle pay-as-you-go. Les ressources Cloud se situent dans un environnement très dynamique. Cependant, chaque ressource provisionnée offre des services fonctionnels et peut ne pas offrir des services non fonctionnels tels que la supervision, la reconfiguration, la sécurité, etc. Dans un tel environnement dynamique, les services non fonctionnels ont une importance critique pour le maintien du niveau de service des ressources ainsi que le respect des contrats entre les fournisseurs et les consommateurs. Dans notre travail, nous nous intéressons à la supervision, la reconfiguration et la gestion autonomique des ressources Cloud. En particulier, nous mettons l'accent sur les applications à base de services. Ensuite, nous poussons plus loin notre travail pour traiter les ressources Cloud d'une manière générale. Par conséquent, cette thèse contient deux contributions majeures. Dans la première contribution, nous étendons le standard SCA (Service Component Architecture) afin de permettre l'ajout de besoins en supervision et reconfiguration à la description des composants. Dans ce contexte, nous proposons une liste de transformations qui permet d'ajouter automatiquement aux composants des facilités de supervision et de reconfiguration, et ce, même si ces facilités n'ont pas été prévues dans la conception des composants. Ceci facilite la tâche au développeur en lui permettant de se concentrer sur les services fonctionnels de ses composants. Pour être en conformité avec la scalabilité des environnements Cloud, nous utilisons une approche basée sur des micro-conteneurs pour le déploiement de composants. Dans la deuxième contribution, nous étendons le standard OCCI (Open Cloud Computing Interface) pour ajouter dynamiquement des facilités de supervision et de reconfiguration aux ressources Cloud, indépendamment de leurs niveaux de service. Cette extension implique la définition de nouvelles Ressources, Links et Mixins OCCI pour permettre d'ajouter dynamiquement des facilités de supervision et de reconfiguration à n'importe quelle ressource Cloud. Nous étendons par la suite nos deux contributions de supervision et reconfiguration afin d'ajouter des capacités de gestion autonomique aux applications SCA et ressources Cloud. Les solutions que nous proposons sont génériques, granulaires et basées sur les standards de facto (i.e., SCA et OCCI). Dans ce manuscrit de thèse, nous décrivons les détails de nos implémentations ainsi que les expérimentations que nous avons menées pour l'évaluation de nos propositions / Cloud Computing is an emerging paradigm in Information Technologies (IT). One of its major assets is the provisioning of resources based on pay-as-you-go model. Cloud resources are situated in a highly dynamic environment. However, each provisioned resource comes with functional properties and may not offer non functional properties like monitoring, reconfiguration, security, accountability, etc. In such dynamic environment, non functional properties have a critical importance to maintain the service level of resources and to make them respect the contracts between providers and consumers. In our work, we are interested in monitoring, reconfiguration and autonomic management of Cloud resources. Particularly, we put the focus on Service-based applications. Afterwards, we push further our work to treat Cloud resources. Consequently, this thesis contains two major contributions. On the first hand, we extend Service Component Architecture (SCA) in order to add monitoring and reconfiguration requirements description to components. In this context, we propose a list of transformations that dynamically adds monitoring and reconfiguration facilities to components even if they were designed without them. That alleviates the task of the developer and lets him focus just on the business of his components. To be in line with scalability of Cloud environments, we use a micro-container based approach for the deployment of components. On the second hand, we extend Open Cloud Computing Interface standards to dynamically add monitoring and reconfiguration facilities to Cloud resources while remaining agnostic to their level. This extension entails the definition of new Resources, Links and Mixins to dynamically add monitoring and reconfiguration facilities to resources. We extend the two contributions to couple monitoring and reconfiguration in order to add self management capabilities to SCA-based applications and Cloud resource. The solutions that we propose are generic, granular and are based on the de facto standards (i.e., SCA and OCCI). In this thesis manuscript, we give implementation details as well as experiments that we realized to evaluate our proposals

Introdução: A adoção de um Sistema de Arquivamento e Distribuição de Imagens (PACS, do inglês Picture Archiving and Communication System) é condição fundamental para a estruturação de um ambiente radiológico sem filme. Um PACS é composto basicamente por equipamentos e sistemas informatizados interconectados em rede, direcionados à aquisição, armazenamento (ou arquivamento), recuperação e apresentação de imagens médicas aos especialistas responsáveis por avaliá-las e laudá-las. A computação em nuvem vem ao encontro dos PACS e surge como uma maneira de simplificar o compartilhamento de imagens entre organizações de saúde e promover a virtualização de espaços físicos e para garantir o seu funcionamento ininterrupto.Objetivo: Este estudo teve como objetivo implementar um PACS simplificado em ambiente cloud computing privado, com foco nas funcionalidades de arquivamento e disponibilização de imagens médicas e avaliar questões de segurança e performance. Metodologia: As imagens que compuseram o PACS do ambiente cloud foram obtidas através do PACS físico atualmente em uso no Centro de Ciência das Imagens e Física Médica do Hospital das Clinicas da Faculdade de Medicina de Ribeirão Preto - CCIFM/HCFMRP. Para os procedimentos da avaliação de segurança foram construídos cenários que possibilitavam a: 1) anominização de dados de identificação dos pacientes através de criptografia computacional em base de dados utilizando o algoritmo de criptografia Advanced Encryption Standard - AES, 2) transferência de imagens médicas seguras através de conexão com a Internet utilizando Virtual Network Private - VPN sobre o protocolo Internet Protocol Security - IPSec (VPN/IPSec) e 3) envio seguro através de tunelamento baseado em Secure Shell - SSH. Resultados: Foi identificada uma queda de performance no envio de informações para a nuvem quando submetidos aos níveis de segurança propostos, sugerindo a relação entre aumento de segurança e perda de performance, apontando para a necessidade de estudos de desempenho quando da condução de projetos envolvam a adoção em ambientes clínicos de solução PACS baseada em cloud computing. / Introduction: the adoption of a PCAS (Picture Archiving and Communication System) is fundamental for the structuring of a radiological environment without film. A PACS comprises, essentially, hardware and information systems interconnected in a network, oriented towards acquisition, storage (or archiving), retrieving and presentation of medical images to specialists entrusted with analyzing and assessing them. Cloud computing comes to support of PCAS, simplifying medical imaging sharing between health care organizations and promoting the virtualization of physical infrastructure to assure uninterrupted availability of the PCAS. Goal: This study aimed to implement a simplified PCAS in a private cloud computing environment, and subsequently to evaluate its security and performance. Methodology: The images that formed the new PCAS were obtained from the exiting PCAS of Centro de Ciência das Imagens e Física Médica of Hospital das Clinicas da Faculdade de Medicina de Ribeirão Preto - CCIFM/HCFMRP. To evaluate its security, scenarios were built within the following framework: 1) patient identification data anonymization through computational database cryptography, using the AES (Advanced Encription Standards) algorithm ; 2) transfer of encrypted medical images on the Internet using VPN (Virtual Private Network) over IPSec (Internet Protocol Security); and 3) safe traffic through Secure Shell (SSH) tunneling. Results: There was a performance drop on traffic of information to the cloud under the proposed security levels that suggests a relationship between increase in security and loss of performance, pointing to the need for performance studies when the project involving driving adoption in clinical environments PACS solution based on cloud computing.

Les clouds sont devenus ces dernières années des plate-formes incontournables dans le monde informatique, car ils permettent de provisionner des ressources à la demande et de ne payer qu’à l’usage. Ceci ouvre la possibilité de concevoir de nouvelles stratégies pour la planification et l’exécution des applications parallèles de type tâches indépendantes ou workflow. Cependant, trouver une stratégie bien adaptée aux contraintes des utilisateurs, que ce soit en termes de coûts et de temps d’exécution, est un problème difficile, pour lequel des outils de prédictions sont nécessaires. Néanmoins, la variabilité inhérente de ces plate-formes complexifient le développement d’un tel outil de prédiction. Notre thèse est que la simulation stochastique est une approche pertinente pour obtenir une prédiction s’accommodant de la variabilité, en produisant une distribution probabiliste des prédictions englobant les résultats réels observables. Pour le démontrer, nous utilisons une méthode de Monte-Carlo permettant de créer des simulations stochastiques par la répétitions de simulations déterministes. Nous montrons que cette méthode associée à certaines distributions d’entrée permettent de modéliser la variabilité d’une plate-forme à travers un unique paramètre. Pour évaluer la méthode proposée, nous comparons les résultats de notre méthode probabiliste à des exécutions réelles d’applications scientifiques. Nos expériences montrent que notre méthode permet de produire des prédictions représentatives des exécutions réelles observées. / The ability to provision resources on the fly and their pay-as-you-go nature has made cloud computing platforms a staple of modern computer infrastructure. Such platforms allow for new scheduling strategies for the execution of computing workloads. Finding a strategy that satisfies a user’s cost and time constraints is a difficult problem that requires a prediction tool. However the inherent variability of these platforms makes building such a tool a complex endeavor. Our thesis is that, by producing probability distributions of possible outcomes, stochastic simulation can be used to produce predictions that account for the variability. To demonstrate this we used Monte Carlo methods to produce a stochastic simulation by repeatedly running deterministic simulations. We show that this method used in conjunction with specific input models can model the variability of a platform using a single parameter. To validate our method we compare our results to real executions of scientific workloads. Our experiments show that our method produces predictions capable of representing theobserved real executions.

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 minimal. / Real 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.

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 minimal. / Real 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.