Le déploiement de logiciels répartis dans des environnements à grande échelle et ouverts (tels les systèmes ubiquitaires, les systèmes mobiles et les systèmes P2P) est une problématique actuelle ouverte. Ces environnements sont distribués, hétérogènes et peuvent être de nature instable (dotés d’une topologie dynamique du réseau). Le déploiement dans ces environnements met en jeu un très grand nombre de machines, de liens réseau ainsi qu’un ensemble de contraintes de déploiement. Quelques solutions de déploiement existent aujourd’hui, mais ne sont exploitables que dans le cadre d’architectures figées et fiables. Dans la plupart des solutions, une personne en charge du déploiement doit décrire plus ou moins manuellement la topologie. En outre, la majorité de ces outils ne prennent pas en compte les problèmes dûs à la variabilité de la qualité de service du réseau, aux pannes des hôtes, aux défaillances des liens du réseau ou encore aux changements dynamiques de topologie, qui caractérisent les environnements ouverts. Dans ce mémoire, nous présentons les motivations de la réalisation d'une infrastructure de déploiement logiciel autonomique et les exigences sous-jacentes d'une telle plate-forme. Nous présentons un état de l’art du déploiement logiciel que nous analysons au regard du contexte visé. Ensuite, nous présentons notre contribution pour le déploiement autonomique. Notre proposition s'appuie sur une combinaison de technologies (composants logiciels, agents mobiles adaptables, intergiciel, langage dédié). Nous proposons j-ASD, un intergiciel qui exploite la complémentarité de ces technologies pour réaliser un déploiement logiciel autonomique. Le processus de déploiement contient trois étapes : description des contraintes de déploiement, résolution, et déploiement autonomique. Pour la première étape, nous avons défini un langage dédié (DSL) comme langage de haut niveau pour exprimer des contraintes de déploiement. Pour la deuxième, nous avons conçu une infrastructure répartie pour collecter les propriétés des sites cibles, ce qui permet de résoudre les contraintes de déploiement. Pour la troisième étape, nous proposons un intergiciel à base d’agents mobiles pour la réalisation et la supervision du déploiement autonomique. Enfin, nous donnons les éléments de conception du prototype que nous avons implémenté, ainsi que les résultats de certaines expérimentations pour montrer la validité de notre approche / Software deployment in large-scale and open distributed systems (such as ubiquitous systems, mobile systems and P2P systems) is still an open issue. These environments are distributed, heterogeneous and can be naturally unstable (fitted with a dynamic network topology). Deployment in such environments require the management of a large number of hosts, network links and deployment constraints. Existing distributed deployment solutions are usable only within static and reliable topologies of hosts, where a man in charge of the deployment has to describe more or less manually the topology. Moreover, majority of these tools do not take into account network and computer QoS variabilities, hosts crashes, network link failures and network topology changes, which characterize open and mobile environments. In this thesis, we discuss the motivations for an autonomic software deployment and the requirements underlying for such a platform. We carefully study and compare the existing work about software deployment. Then, we propose a middleware framework, designed to reduce the human cost for setting up software deployment and to deal with failure-prone and change-prone environments. We also propose an autonomic deployment process in three steps : deployment constraints description step, constraints resolution step and the autonomic deployment step. For the first step, we defined a high-level constraint-based dedicated language (DSL) as support for expressing deployment constraints. In the second step, we have designed a distributed infrastructure to collect target hosts properties used to solve deployment constraints. For the third step, we propose an agent-based system for establishing and maintaining software deployment. At last, we give an overview of our working prototype with some details on some experimental results

With the fast development of wireless networks and devices, Mobile IP is expected to be used widely so that mobile users can access the Internet anywhere, anytime without interruption. However, some problems, such as firewall traversal and use of private IP addresses, restrict use of Mobile IP. The objective of this thesis is to design original schemes that can enable a mobile node at abroad to access its home network as well as the Internet securely and that can help Mobile IP to be used widely and commercially. Our solutions are secure, efficient, and scalable. They can be implemented and maintained easily. In this thesis, we mainly consider Mobile IPv4, instead of Mobile IPv6. Three research topics are discussed. In each topic, the challenges are investigated and the new solutions are presented. The first research topic solves the firewall traversal problems in Mobile IP. A mobile node cannot access its firewall-protected home network if it fails the authentication by the firewall. We propose that an IPsec tunnel be established between the firewall and the foreign agent for firewall traversal and that an IPsec transport security association be shared by the mobile node and a correspondent node for end-to-end security. The second topic researches further on firewall traversal problems and investigates the way of establishing security associations among network entities. A new security model and a new key distribution method are developed. With the help of the security model and keys, the firewall and the relevant network entities set up IPsec security associations to achieve firewall traversal. A mobile node from a private home network cannot communicate with other hosts with its private home address when it is visiting a public foreign network. A novel and useful solution is presented in the third research topic. We suggest that the mobile node use its Network Access Identifier (NAI) as its identification and obtain a public home address from its home agent. In addition, a new tunnel between the mobile node and its home agent is proposed.

Made available in DSpace on 2016-08-17T14:52:33Z (GMT). No. of bitstreams: 1 Rafael Fernandes Lopes.pdf: 4191329 bytes, checksum: d7582da9cb0e7c9fbb1def0451444863 (MD5) Previous issue date: 2006-01-13 / In recent years, Grid computing has emerged as a promising alternative to the integration and sharing of multi-institutional resources. However, constructing a Grid middleware is a complex task. Developers must address several design and implementation challenges, such as: e±cient management and allocation of distributed resources, dynamic task scheduling, high scalability and heterogeneity, fault tolerance, e±cient mechanisms for collaborative communication among Grid nodes, and security issues. MAG (Mobile Agents for Grid Computing Environments) explores the mobile agent technology as a way to overcome several of these challenges. MAG middleware executes Grid applications by dynamically loading the application code into a mobile agent. The MAG agent can be dynamically reallocated among Grid nodes through a transparent migration mechanism called MAG/Brakes, as a way to provide load balancing and support for non-dedicated nodes. MAG middleware also includes mechanisms for providing application fault tolerance, an essential characteristic for Grid environments. We make extensive use of the agent paradigm to design and implement MAG components, forming a multi-agent infrastructure for computational Grids. This master thesis describes MAG and MAG/Brakes architecture, implementation and performance issues. / Nos ultimos anos, a computação em grade tem emergido como uma promissora alternativa para a integração e compartilhamento de recursos multi-institucionais. Entretanto, a construçãoo de um middleware de grade é uma tarefa complexa. Desenvolvedores devem lidar com vários desafios de projeto e implementação, como: gerenciamento e alocação suficiente de recursos distribuidos, escalonamento dinâmico de tarefas, alta escalabilidade e heterogeneidade, tolerância a falhas, mecanismos suficientes para a comunicação colaborativa entre nós da grade e aspectos de segurança; O MAG (Mobile Agents for Grid Computing Environments) explora a tecnologia de agentes móveis como uma forma de superar vários destes desafios. O middleware MAG executa as aplicações da grade carregando dinamicamente o código da aplicação no agente movel. O agente do MAG pode ser realocado dinamicamente entre nós da grade através de um mecanismo de migração transparente chamado MAG/Brakes, como uma forma de prover balanceamento de carga e suporte para nós não dedicados. O middleware MAG também inclui mecanismos para prover tolerância a falhas de aplicações, uma caracteristica essencial para ambientes de grade. O paradigma de agentes foi extensivamente utilizado para projetar e implementar os componentes do MAG, formando uma infraestrutura multiagente para grades computacionais. Esta dissertação de mestrado descreve a arquitetura, implementação e aspectos de desempenho do MAG e do MAG/Brakes.

Orientador: Manuel de Jesus Mendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T00:34:30Z (GMT). No. of bitstreams: 1 Silva_PauloSergioda_D.pdf: 1777936 bytes, checksum: 623cb05483de0ceb59da755ce1eb66ce (MD5) Previous issue date: 2004 / Resumo: Este trabalho contribui para a convergência de agentes móveis e agentes inteligentes através da proposta de um framework para incorporar técnicas de Inteligência Artificial (IA) a agentes móveis criados com os principais sistemas de mobilidade contemporâneos baseados em Java. Os requisitos a serem satisfeitos pelo framework são identificados e sua arquitetura é estabelecida. Um dos principais mecanismos de IA, o mecanismo de inferência com encadeamento progressivo baseado em regras, é implementado de acordo com o framework sugerido. Uma metodologia de desenvolvimento de software orientada a objetos e vários padrões de projeto são utilizados na concepção tanto do framework quanto do mecanismo de inferência. Os modelos resultantes são documentados através da Linguagem Unificada de Modelagem (UML) e as principais decisões de projeto, na forma de diretrizes a serem adotadas na criação de outros mecanismos. A proposta é avaliada através da construção de agentes móveis controlados pelo mecanismo desenvolvido e pelo levantamento do custo de transporte de seu código e dados. Os resultados mostram que o framework é viável e que o custo de transporte do mecanismo implementado é bem menor que o dos equivalentes encontrados na literatura / Abstract: This thesis contributes for the convergence of mobile and intelligent agents by proposing a framework for embedding Artificial Intelligence (AI) techniques in mobile agents built with the main actual Java-based mobile agent systems. The requirements to be satisfied by the framework are identified and its architecture is established. One of the most essential AI engines, the rule-based forward-chaining inference engine is implemented in agreement with the suggested framework. An object-oriented software development methodology and several design patterns are used in the conception of both, the framework and the inference engine. The resulting models are documented using the Unified Modeling Language (UML) and the main design decisions, as directions to be adopted in the development of other engines. The proposal is evaluated by the construction of mobile agents controlled by the developed engine and by the estimation of the transportation cost of the engine¿s code and data. The results show the framework is feasible and that the transportation cost of the implemented engine is much lower than the cost of similar engines found in literature / Doutorado / Engenharia de Computação / Doutor em Engenharia Elétrica

Orientador: Mauricio Ferreira Magalhães / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T04:09:19Z (GMT). No. of bitstreams: 1 Guimaraes_ElianeGomes_D.pdf: 1203376 bytes, checksum: 8baa98d5b0b9753d8a292e0c940b5f41 (MD5) Previous issue date: 2004 / Resumo: Esta tese descreve CM-tel, um modelo de componentes para aplicações telemáticas e ubíquas. CM-tel é neutro em termos de tecnologia, sendo especificado por meio da linguagem UML (Unified Modeling Language). Componentes CM-tel são capazes de executar em plataformas destinadas tanto a computadores tradicionais quanto a dispositivos com limitado poder computacional tais como dispositivos móveis. CM-tel define os três tipos de interfaces prescritas pelo Modelo de Referência para Processamento Distribuído Aberto (RM-ODP), as interfaces operacional, de sinal e de fluxo contínuo. Interfaces de fluxo contínuo são fundamentais para o desenvolvimento de aplicações telemáticas. A arquitetura do contêiner CM-tel integra componentes e agentes móveis em um único ambiente computacional. Esta integração permite que aplicações implementem suas funcionalidades combinando componentes e agentes móveis. Esta tese propõe ainda uma arquitetura para plataformas de software que suportam o modelo CM-tel. A arquitetura utiliza XSLT (XML Stylesheet Language Transformation) para transformação de modelos e geração de código. Uma plataforma baseada na tecnologia CORBA (Common Object Request Broker Architecture) e uma aplicação na área de laboratórios virtuais foram implementadas com a finalidade de avaliar o modelo CM-tel / Abstract: This thesis describes CM-tel, a component model for telematic and ubiquitous applications. CMtel is neutral in terms technology and is specified through the Unified Modeling Language (UML). CM-tel components can execute on platforms targeted to both conventional computers and devices with limited computing power such as mobile devices. CM-tel defines the three types of interfaces prescribed by the Reference Model for Open Distributed Processing (RM-ODP), the operational, signal, and stream interfaces. Stream interfaces are central to the development of telematic applications. The CM-tel container architecture integrates both components and mobile agents into a single computing environment. This integration allows applications to implement their functionalities by combining components and mobile agents. This thesis also proposes an architecture for software platforms supportting the CM-tel component model. The architecture relies on XSLT (XML Stylesheet Language Transformation) for model transformation and code generation. A platform based on the CORBA (Common Object Request Broker Architecture) technology and an application in the field of virtual laboratories were implemented in order to assess the CM-tel component model / Doutorado / Engenharia de Computação / Doutor em Engenharia Elétrica

Ce travail appartient au domaine de la simulation numérique sur des plates-formes d'exécution distribuées hétérogènes telles que des grilles de calcul. Ce type de plate-forme se caractérise par des possibles changements de condition d'exécution et par une probabilité importante de défaillance de certains composants. Une application qui s'exécute dans un tel environnement se doit d'être adaptable à son contexte d'exécution et tolérante aux pannes. Face à la complexité croissante de la mise en place de cas de calcul sur des grilles de calcul, nous proposons une plateforme logicielle pour la résolution de cas de calcul numérique dans un environnement distribué hétérogène. Nos travaux apportent une solution qui se base sur un système d'agents mobiles, ce qui permet à une application de s'adapter au changement de son environnement d'exécution. Dans un premier temps, nous utilisons le langage pi calcul d'ordre supérieur pour spécifier une « ferme de travailleurs » capable de participer à la résolution de tout type de cas de calcul. Ensuite, nous énonçons des propriétés qui caractérisent le bon fonctionnement de ce système avec une logique temporelle TCTL. Pour cela, nous souhaitons modéliser notre système à l'aide d'automates temporisés à partir des termes définis par la spécification formelle en pi calcul. Dans ce but, nous définissons une transformation de termes écrits en pi calcul en automates temporisés. Les propriétés sont alors vérifiées avec l'outil UppAal. Pour valider ce travail de modélisation, nous avons réalisé le framework MCA (pour Mobile Computing Architecture). Celui-ci propose un ensemble d'outils facilitant la mise en place de composants sur un environnement distribué hétérogène dans le but d'effectuer la résolution de cas de calcul. La librairie avec laquelle sont développés ces composants, qu'ils soient mobiles ou non, est implantée en Java et se base les technologies Jini et JavaSpaces. Enfin, nous réalisons l'évaluation du framework MCA en procédant à la résolution de trois cas de calcul différents. Chacune de ces expériences, réalisées sur une grappe de 20 noeuds, nous permet de montrer les caractéristiques essentielles de notre framework : une simplicité de programmation, un faible surcoût en temps d'exécution sans l'activation de la tolérance aux pannes et une tolérance aux pannes efficace / This work belongs to the domain of numerical simulation on heterogeneous distributed platforms such as grids. This type of platform is characterized by possible changes in execution conditions and a significant probability of some components failure. An application running in such an environment must be adaptable to its execution context and fault tolerant. Facing the growing complexity of implementing computation cases on grid computing, we propose a software platform which solves numerical computation cases in a distributed heterogeneous environment. Our work provides a solution based on a mobile agent system, which allows an application to adapt to change in its execution environment. At first, we use the higher-order pi calculus language to specify a « farm of workers » able to take part in solving any type of computation case. Then we set the properties that characterize the system's correct execution with a temporal logic TCTL. In order to do this, we perform a temporal modeling system based on terms defined by the formal specification in pi calculus. To achieve this transformation, we define a translation of terms written in pi calculus into timed automata. The properties are verified with the UppAal tool. To validate this modeling work, we develop the MCA (for Mobile Computing Architecture) framework. It offers a set of tools which facilitate the implementation of distributed heterogeneous components in order to solve computation cases. These components, mobile or not, are developed with a library written in Java and which uses Jini and JavaSpaces technologies. Finally, our framework is evaluated through the resolution of three different computation cases. Each of these experiments, performed on a 20 node cluster allow us to highlight our framework's main characteristics : programming simplicity, low overhead in execution time without the fault tolerance activation and efficient fault tolerance

This thesis presents the developed taxonomy of the security threats in agent-based distributed systems. Based on this taxonomy, a set of theories is developed to facilitate analyzng the security threats of the mobile-agent systems. We propose the idea of using the developed security risk graph to model the system's vulnerabilties.

La maitrise de la complexité croissante tant de nos organisations socioéconomiques que de nos systèmes et infrastructures technologiques, impose des systèmes informatiques de plus en plus intégrés. L’organisation de nos sociétés avancées ne pourrait plus se développer dans des conditions raisonnables sans le support des technologies de l’information. Les différents systèmes d’information s’intègrent ainsi de plus en plus en un maillage informationnel formant ainsi un système de systèmes qui se complexifie de jour en jour et de ce fait devient de plus en plus vital. Ces systèmes des systèmes doivent répondre à deux types d’objectifs : i) la réalisation d’un système par l’intégration de systèmes offerts par différents fournisseurs, ii) l’interopération de systèmes déjà en service en vue d’obtenir des propriétés nouvelles dues à leur coopération, généralement avec une augmentation d’efficacité. Ces objectifs et cette complexité ne peuvent être appréhendés par une démarche purement analytique. C’est pourquoi nous avons préconisé à travers cette thèse une solution de système de systèmes basée sur un graphe d'interopérabilité construit sur une comparaison hiérarchique ontologique. La mise en œuvre de cette approche à travers l’utilisation d’une plateforme d’agents mobile permet une recherche dynamique de services visant à satisfaire au mieux les critères de qualité exigés par l’utilisateur. / Mastering the increasing complexity of our socio-economic organizations and technology infrastructure requires more and more integrated information systems. The organization of our advanced societies could no longer grow on reasonable terms without the support of information technology.The different information systems belongs more and more to an informational meshing, forming in this way a complex system of systems which is getting complex day after day and because of that is becoming increasingly vital.This system of systems must meet two objectives: i) implementation of a system by integrating systems offered by different providers, ii) interoperation of systems already in use in order to obtain new properties due to their cooperation, usually with an efficiency increase.These objectives and this complexity can be grasped by a purely analytical approach. That is why we have advocated throughout this thesis a solution of system of systems based on an interoperability graph built on a hierarchical ontological comparison (foundation of trust). The platform of mobile agents associated with this system will implement a dynamic search of services which tries to satisfy the quality criteria required by the user.

In this dissertation, we describe the portable, open-source distributed simulation framework (WINDS) targeting simulations of wireless network infrastructures that we have developed. We present the simulation framework which uses modular architecture and apply the framework to studies of mobility pattern effects, routing and intrusion detection mechanisms in simulations of large-scale wireless ad hoc, infrastructure, and totally mobile networks. The distributed simulations within the framework execute seamlessly and transparently to the user on a symmetric multiprocessor cluster computer or a network of computers with no modifications to the code or user objects. A visual graphical interface precisely depicts simulation object states and interactions throughout the simulation execution, giving the user full control over the simulation in real time. The network configuration is detected by the framework, and communication latency is taken into consideration when dynamically adjusting the simulation clock, allowing the simulation to run on a heterogeneous computing system. The simulation framework is easily extensible to multi-cluster systems and computing grids. An entire simulation system can be constructed in a short time, utilizing user-created and supplied simulation components, including mobile nodes, base stations, routing algorithms, traffic patterns and other objects. These objects are automatically compiled and loaded by the simulation system, and are available for dynamic simulation injection at runtime. Using our distributed simulation framework, we have studied modern intrusion detection systems (IDS) and assessed applicability of existing intrusion detection techniques to wireless networks. We have developed a mobile agent-based IDS targeting mobile wireless networks, and introduced load-balancing optimizations aimed at limited-resource systems to improve intrusion detection performance. Packet-based monitoring agents of our IDS employ a CASE-based reasoner engine that performs fast lookups of network packets in the existing SNORT-based intrusion rule-set. Experiments were performed using the intrusion data from MIT Lincoln Laboratories studies, and executed on a cluster computer utilizing our distributed simulation system.

The mobility attribute of a mobile agent implies deployment thereof in untrustworthy environments, which introduces malicious host threats. The research question deals with how a security framework could be constructed to address the mentioned threats without introducing high costs or restraining the mobile agent's autonomy or performance. Available literature have been studied, analysed and discussed. The salient characteristics as well as the drawbacks of current solutions were isolated. Through this knowledge a dynamic mobile agent security framework was defined. The framework is based on the definition of multiple security levels, depending on type of deployment environment and type of application. A prototype was constructed and tested and it was found to be lightweight and efficient, giving developers insight into possible security threats as well as tools for maximum protection against malicious hosts. The framework outperformed other frameworks / models as it provides dynamic solutions without burdening a system with unnecessary security gadgets and hence paying for it in system cost and performance / Computing / D.Phil.