135 research outputs found

    InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services

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    Cloud computing providers have setup several data centers at different geographical locations over the Internet in order to optimally serve needs of their customers around the world. However, existing systems do not support mechanisms and policies for dynamically coordinating load distribution among different Cloud-based data centers in order to determine optimal location for hosting application services to achieve reasonable QoS levels. Further, the Cloud computing providers are unable to predict geographic distribution of users consuming their services, hence the load coordination must happen automatically, and distribution of services must change in response to changes in the load. To counter this problem, we advocate creation of federated Cloud computing environment (InterCloud) that facilitates just-in-time, opportunistic, and scalable provisioning of application services, consistently achieving QoS targets under variable workload, resource and network conditions. The overall goal is to create a computing environment that supports dynamic expansion or contraction of capabilities (VMs, services, storage, and database) for handling sudden variations in service demands. This paper presents vision, challenges, and architectural elements of InterCloud for utility-oriented federation of Cloud computing environments. The proposed InterCloud environment supports scaling of applications across multiple vendor clouds. We have validated our approach by conducting a set of rigorous performance evaluation study using the CloudSim toolkit. The results demonstrate that federated Cloud computing model has immense potential as it offers significant performance gains as regards to response time and cost saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape

    Enabling virtualization technologies for enhanced cloud computing

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    Cloud Computing is a ubiquitous technology that offers various services for individual users, small businesses, as well as large scale organizations. Data-center owners maintain clusters of thousands of machines and lease out resources like CPU, memory, network bandwidth, and storage to clients. For organizations, cloud computing provides the means to offload server infrastructure and obtain resources on demand, which reduces setup costs as well as maintenance overheads. For individuals, cloud computing offers platforms, resources and services that would otherwise be unavailable to them. At the core of cloud computing are various virtualization technologies and the resulting Virtual Machines (VMs). Virtualization enables cloud providers to host multiple VMs on a single Physical Machine (PM). The hallmark of VMs is the inability of the end-user to distinguish them from actual PMs. VMs allow cloud owners such essential features as live migration, which is the process of moving a VM from one PM to another while the VM is running, for various reasons. Features of the cloud such as fault tolerance, geographical server placement, energy management, resource management, big data processing, parallel computing, etc. depend heavily on virtualization technologies. Improvements and breakthroughs in these technologies directly lead to introduction of new possibilities in the cloud. This thesis identifies and proposes innovations for such underlying VM technologies and tests their performance on a cluster of 16 machines with real world benchmarks. Specifically the issues of server load prediction, VM consolidation, live migration, and memory sharing are attempted. First, a unique VM resource load prediction mechanism based on Chaos Theory is introduced that predicts server workloads with high accuracy. Based on these predictions, VMs are dynamically and autonomously relocated to different PMs in the cluster in an attempt to conserve energy. Experimental evaluations with a prototype on real world data- center load traces show that up to 80% of the unused PMs can be freed up and repurposed, with Service Level Objective (SLO) violations as little as 3%. Second, issues in live migration of VMs are analyzed, based on which a new distributed approach is presented that allows network-efficient live migration of VMs. The approach amortizes the transfer of memory pages over the life of the VM, thus reducing network traffic during critical live migration. The prototype reduces network usage by up to 45% and lowers required time by up to 40% for live migration on various real-world loads. Finally, a memory sharing and management approach called ACE-M is demonstrated that enables VMs to share and utilize all the memory available in the cluster remotely. Along with predictions on network and memory, this approach allows VMs to run applications with memory requirements much higher than physically available locally. It is experimentally shown that ACE-M reduces the memory performance degradation by about 75% and achieves a 40% lower network response time for memory intensive VMs. A combination of these innovations to the virtualization technologies can minimize performance degradation of various VM attributes, which will ultimately lead to a better end-user experience

    An innovative approach to performance metrics calculus in cloud computing environments: a guest-to-host oriented perspective

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    In virtualized systems, the task of profiling and resource monitoring is not straight-forward. Many datacenters perform CPU overcommittment using hypervisors, running multiple virtual machines on a single computer where the total number of virtual CPUs exceeds the total number of physical CPUs available. From a customer point of view, it could be indeed interesting to know if the purchased service levels are effectively respected by the cloud provider. The innovative approach to performance profiling described in this work is based on the use of virtual performance counters, only recently made available by some hypervisors to their virtual machines, to implement guest-wide profiling. Although it isn't possible for the virtual machine to access Virtual Machine Monitor, with this method it is able to gather interesting informations to deduce the state of resource overcommittment of the virtualization host where it is executed. Tests have been carried out inside the compute nodes of FIWARE Genoa Node, an instance of a widely distributed federated community cloud, based on OpenStack and KVM. AgiLab-DITEN, the laboratory I belonged to and where I conducted my studies, together with TnT-Lab\u2013DITEN and CNIT-GE-Unit designed, installed and configured the whole Genoa Node, that was hosted on DITEN-UniGE equipment rooms. All the software measuring instruments, operating systems and programs used in this research are publicly available and free, and can be easily installed in a micro instance of virtual machine, rapidly deployable also in public clouds

    Building the Infrastructure for Cloud Security

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    Experimental evaluation of a CPU Live Migration on ARM based Bare metal Instances

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    The advent of 5G and the adoption of digitalization in all areas of industry has resulted in the exponential growth of the Internet of Things (IoTs) devices, increasing the flow of data that travels back and forth to a centralized Cloud data centre for storage, processing, and analysis. This in turn puts pressure on the intermediate edge and core network infrastructure as traditional Cloud Computing is not ready to support this massive amount and diversity of devices and data. This need for faster processing, low latency and higher network consistency makes a case for Edge Computing solutions. However, applying Edge Computing as a solution to overcome the network performance limitations that exist on an “IoT to Cloud” architecture while continuing to use Virtualization technology for system utilization is a bit of an oxymoron. Virtualization increases performance overheads, while sharing network resources among users and applications creates further bandwidth limitations and latency since communications are still served through the same physical network interfaces. The demand for network and system consistency, finer security and privacy has led to the deployment of Bare metal instances. Bare metal instances are nothing more than traditional servers that lack the virtualization layer offering native performance to the user. Furthermore, the rise of the ARM processors and the introduction of cheap low power architectures targeted to the Edge introduce a compelling new candidate platform especially on Bare metal instances. Live migration is a valuable tool for increasing applications and users’ mobility, service availability offering workload balancing and fault tolerance. However, live migration is tied to the existence of a virtualization layer therefore implementing a live migration process on Bare metal instances is very challenging. To the best of our knowledge, there is no existing proposal for a Bare metal live migration scheme on ARM based systems. Therefore, this thesis presents a novel design, implementation, and evaluation of an ARM based live migration scheme for Bare metal instances suitable for modern EdgeComputing Micro Data Centres. Our experimental evaluation confirms the effectiveness of our novel design as well as highlighting the importance on identifying the number of registers that describe and are critical for the reconstruction of the CPU state at the destination

    Implementing Virtualization on Single-Board Computers: A Case Study on Edge Computing

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    The widespread adoption of cloud computing has resulted in centralized datacenter structures; however, there is a requirement for smaller-scale distributed infrastructures to meet the demands for speed, responsiveness, and security for critical applications. Single-Board Computers (SBCs) present numerous advantages such as low power consumption, low cost, minimal heat emission, and high processing power, making them suitable for applications such as the Internet of Things (IoT), experimentation, and other advanced projects. This paper investigates the possibility of adopting virtualization technology on Single-Board Computers (SBCs) for the implementation of reliable and cost-efficient edge-computing environments.The results of this study are based on experimental implementations and testing conducted in the course of a case study performed on the edge infrastructure of a financial organization, where workload migration was achieved from a traditional to an SBC-based edge infrastructure. The performance of the two infrastructures was studied and compared during this process, providing important insights into the power efficiency gains, resource utilization, and overall suitability for the organization’s operational needs

    Automated Security Analysis of Virtualized Infrastructures

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    Virtualization enables the increasing efficiency and elasticity of modern IT infrastructures, including Infrastructure as a Service. However, the operational complexity of virtualized infrastructures is high, due to their dynamics, multi-tenancy, and size. Misconfigurations and insider attacks carry significant operational and security risks, such as breaches in tenant isolation, which put both the infrastructure provider and tenants at risk. In this thesis we study the question if it is possible to model and analyze complex, scalable, and dynamic virtualized infrastructures with regard to user-defined security and operational policies in an automated way. We establish a new practical and automated security analysis framework for virtualized infrastructures. First, we propose a novel tool that automatically extracts the configuration of heterogeneous environments and builds up a unified graph model of the configuration and topology. The tool is further extended with a monitoring component and a set of algorithms that translates system changes to graph model changes. The benefits of maintaining such a dynamic model are time reduction for model population and closing the gap for transient security violations. Our analysis is the first that lifts static information flow analysis to the entire virtualized infrastructure, in order to detect isolation failures between tenants on all resources. The analysis is configurable using customized rules to reflect the different trust assumptions of the users. We apply and evaluate our analysis system on the production infrastructure of a global financial institution. For the information flow analysis of dynamic infrastructures we propose the concept of dynamic rule-based information flow graphs and develop a set of algorithms that maintain such information flow graphs for dynamic system models. We generalize the analysis of isolation properties and establish a new generic analysis platform for virtualized infrastructures that allows to express a diverse set of security and operational policies in a formal language. The policy requirements are studied in a case-study with a cloud service provider. We are the first to employ a variety of theorem provers and model checkers to verify the state of a virtualized infrastructure against its policies. Additionally, we analyze dynamic behavior such as VM migrations. For the analysis of dynamic infrastructures we pursue both a reactive as well as a proactive approach. A reactive analysis system is developed that reduces the time between system change and analysis result. The system monitors the infrastructure for changes and employs dynamic information flow graphs to verify, for instance, tenant isolation. For the proactive analysis we propose a new model, the Operations Transition Model, which captures the changes of operations in the virtualized infrastructure as graph transformations. We build a novel analysis system using this model that performs automated run-time analysis of operations and also offers change planning. The operations transition model forms the basis for further research in model checking of virtualized infrastructures

    Supporting Virtualisation Management through an Object Mapping Declarative Language Framework

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    Due to the inevitably vast scale of virtualised cloud computing systems, management of the numerous physical and virtual components that make up their underlying infrastructure may become unwieldy. Many software packages that have historically been installed on desktops / workstations for years are slowly but surely being ported to cloud computing. The virtualisation management problems that are apparent today are only set to worsen as cloud computing systems become ever more pervasive. Backing cloud computing systems are equally elaborate database systems, many platforms of which have made extensive use of distributed computing and virtualisation for years. The more recent emergence of virtualised big data systems with similarly vast scale problems has escalated the urgent requirement for creative management of the numerous physical and virtual components. The thesis will initially synopsise previous investigatory research concerning these emerging problems and studies the current disposition of virtualisation management including the associated concepts, strategies and technologies. The thesis then continues, to describe the structure and operation of an object mapping declarative language to support the management of these numerous physical and virtual components. The ultimate aim is to develop a Virtualisation Management System (VMS), a software framework that is fully extensible in nature and which combines the rich capability of an imperative assembly with the concise simplicity of a declarative language. It is through this declarative language that human interaction and decision making may be richly yet concisely specified before being converted through object mapping to the comparable imperative assembly for execution. It is also through parsing this declarative language that autonomic algorithms may be able to integrate with and operate the VMS through a suitably defined plug-in based mechanism. The thesis will ultimately demonstrate via scenarios both basic and complex that the VMS is able to specify, observe, regulate and adapt its virtualisation management domain to the changing disposition of the numerous physical and virtual components that constitute cloud computing and big data systems

    Virtual Organization Clusters: Self-Provisioned Clouds on the Grid

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    Virtual Organization Clusters (VOCs) provide a novel architecture for overlaying dedicated cluster systems on existing grid infrastructures. VOCs provide customized, homogeneous execution environments on a per-Virtual Organization basis, without the cost of physical cluster construction or the overhead of per-job containers. Administrative access and overlay network capabilities are granted to Virtual Organizations (VOs) that choose to implement VOC technology, while the system remains completely transparent to end users and non-participating VOs. Unlike alternative systems that require explicit leases, VOCs are autonomically self-provisioned according to configurable usage policies. As a grid computing architecture, VOCs are designed to be technology agnostic and are implementable by any combination of software and services that follows the Virtual Organization Cluster Model. As demonstrated through simulation testing and evaluation of an implemented prototype, VOCs are a viable mechanism for increasing end-user job compatibility on grid sites. On existing production grids, where jobs are frequently submitted to a small subset of sites and thus experience high queuing delays relative to average job length, the grid-wide addition of VOCs does not adversely affect mean job sojourn time. By load-balancing jobs among grid sites, VOCs can reduce the total amount of queuing on a grid to a level sufficient to counteract the performance overhead introduced by virtualization

    Cloud provider independence using DevOps methodologies with Infrastructure-as-Code

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    On choosing cloud computing infrastructure for IT needs there is a risk of becoming dependent and locked-in on a specific cloud provider from which it becomes difficult to switch should an entity decide to move all of the infrastructure resources into a different provider. There’s widespread information available on how to migrate existing infrastructure to the cloud notwithstanding common cloud solutions and providers don't have any clear path or framework for supporting their tenants to migrate off the cloud into another provider or cloud infrastructure with similar service levels should they decide to do so. Under these circumstances it becomes difficult to switch from cloud provider not just because of the technical complexity of recreating the entire infrastructure from scratch and moving related data but also because of the cost it may involve. One possible solution is to evaluate the use of Infrastructure-as-Code languages for defining infrastructure (“Infrastructure-as-Code”) combined with DevOps methodologies and technologies to create a mechanism that helps streamline the migration process between different cloud infrastructure especially if taken into account from the beginning of a project. A well-structured DevOps methodology combined with Infrastructure-as-Code may allow a more integrated control on cloud resources as those can be defined and controlled with specific languages and be submitted to automation processes. Such definitions must take into account what is currently available to support those operations under the chosen cloud infrastructure APIs, always seeking to guarantee the tenant an higher degree of control over its infrastructure and higher level of preparation of the necessary steps for the recreation or migration of such infrastructure should the need arise, somehow integrating cloud resources as part of a development model. The objective of this dissertation is to create a conceptual reference framework that can identify different forms for migration of IT infrastructure while always contemplating a higher provider independence by resorting to such mechanisms, as well as identify possible constraints or obstacles under this approach. Such a framework can be referenced from the beginning of a development project if foreseeable changes in infrastructure or provider are a possibility in the future, taking into account what the API’s provide in order to make such transitions easier.Ao optar-se por infraestruturas de computação em nuvem para soluções de TI existe um risco associado de se ficar dependente de um fornecedor de serviço específico, do qual se torna difícil mudar caso se decida posteriormente movimentar toda essa infraestrutura para um outro fornecedor. Encontra-se disponível extensa documentação sobre como migrar infraestrutura já  existente para modelos de computação em nuvem, de qualquer modo as soluções e os fornecedores de serviço não dispõem de formas ou metodologias claras que suportem os seus clientes em migrações para fora da nuvem, seja para outro fornecedor ou infraestrutura com semelhantes tipos de serviço, caso assim o desejem. Nestas circunstâncias torna-se difícil mudar de fornecedor de serviço não apenas pela complexidade técnica associada à criação de toda a infraestrutura de raiz e movimentação de todos os dados associados a esta mas também devido aos custos que envolve uma operação deste tipo. Uma possível solução é avaliar a utilização de linguagens para definição de infraestrutura como código (“Infrastructure-as-Code”) em conjunção com metodologias e tecnologias “DevOps” de forma a criar um mecanismo que permita flexibilizar um processo de migração entre diferentes infraestruturas de computação em nuvem, especialmente se for contemplado desde o início de um projecto. Uma metodologia “DevOps” devidamente estruturada quando combinada com definição de infraestrutura como código pode permitir um controlo mais integrado de recursos na nuvem uma vez que estes podem ser definidos e controlados através de linguagens específicas e submetidos a processos de automação. Tais definições terão de ter em consideração o que existe disponível para suportar as necessárias operações através das “API’s” das infraestruturas de computação em nuvem, procurando sempre garantir ao utilizador um elevado grau de controlo sobre a sua infraestrutura e um maior nível de preparação dos passos necessários para recriação ou migração da infraestrutura caso essa necessidade surja, integrando de certa forma os recursos de computação em nuvem como parte do modelo de desenvolvimento. Esta dissertação tem como objetivo a criação de um modelo de referência conceptual que identifique formas de migração de infraestruturas de computação procurando ao mesmo tempo uma maior independência do fornecedor de serviço com recurso a tais mecanismos, assim como identificar possíveis constrangimentos ou impedimentos nesta aproximação. Tal modelo poderá ser referenciado desde o início de um projecto de desenvolvimento caso seja necessário contemplar uma possível necessidade futura de alterações ao nível da infraestrutura ou de fornecedor, com base no que as “API’s” disponibilizam, de modo a facilitar essa operação.info:eu-repo/semantics/publishedVersio
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