MACHS: Mitigating the Achilles Heel of the Cloud through High Availability and Performance-aware Solutions

Cloud computing is continuously growing as a business model for hosting information and communication technology applications. However, many concerns arise regarding the quality of service (QoS) offered by the cloud. One major challenge is the high availability (HA) of cloud-based applications. The key to achieving availability requirements is to develop an approach that is immune to cloud failures while minimizing the service level agreement (SLA) violations. To this end, this thesis addresses the HA of cloud-based applications from different perspectives. First, the thesis proposes a component’s HA-ware scheduler (CHASE) to manage the deployments of carrier-grade cloud applications while maximizing their HA and satisfying the QoS requirements. Second, a Stochastic Petri Net (SPN) model is proposed to capture the stochastic characteristics of cloud services and quantify the expected availability offered by an application deployment. The SPN model is then associated with an extensible policy-driven cloud scoring system that integrates other cloud challenges (i.e. green and cost concerns) with HA objectives. The proposed HA-aware solutions are extended to include a live virtual machine migration model that provides a trade-off between the migration time and the downtime while maintaining HA objective. Furthermore, the thesis proposes a generic input template for cloud simulators, GITS, to facilitate the creation of cloud scenarios while ensuring reusability, simplicity, and portability. Finally, an availability-aware CloudSim extension, ACE, is proposed. ACE extends CloudSim simulator with failure injection, computational paths, repair, failover, load balancing, and other availability-based modules

Evaluation and Deployment of a Private Cloud Framework at DI-FCT-NOVA

In today’s technological landscape, there is an ever-increasing demand for computing resources for simulations, machine learning, or other use-cases. This demand can be seen across the business world, with the success of Amazon’s AWS and Microsoft’s Azure offer- ings, which provide a cloud of on-demand computing resources to any paying customer. The necessity for computing resources is no less felt in the academic world, where departments are forced to assign researchers and teachers to time-consuming system administrator roles, to allocate resources to users, leading to delays and wasted potential. Allowing researchers to request computing resources and then get them, on-demand, with minimal input from any administrative staff, is a great boon. Not only does it increase productivity of the administrators themselves, but it also allows users (teachers, researchers and students) to get the resources they need faster, and more securely. This goal is attainable through the use of a cloud management framework to assist in the administration of a department’s computing infrastructure. This dissertation aims to provide a critical evaluation on the adequacy of three cloud management frameworks, evaluating the requirements for a private cloud at the DI- FCT-NOVA, as well as which features of the selected cloud framework may be used in the fulfilment of the department’s needs. The final goal is to architect and deploy the selected framework to DI-FCT-NOVA, which will give the department a maintainable state-of-the-art private cloud deployment, capable of adequately responding to the needs of its users.No cenário tecnológico atual, existe uma necessidade crescente por recursos computaci- onais quer para simulações, aprendizagem automática, ou outros fins. Essa necessidade pode ser vista no mundo dos negócios, traduzindo-se no sucesso da Amazon AWS e a da Microsoft Azure, entre outras, que oferecem clouds de recursos computacionais a qualquer cliente, sujeito a diferentes formas de pagamento. A necessidade de recursos computacionais não é menos sentida no mundo académico, onde departamentos são forçados a atribuir a investigadores e professores tarefas onerosas que desperdiçam o seu potencial, como administração de sistemas computacionais com o fim de alocar recursos quem deles necessita (docentes, investigadores e estudantes). Permitir que se peçam recursos computacionais, e estes sejam alocados com o mínimo de interacção de uma equipa administrativa, é um grande benefício. Isto não só aumenta a produtividade dos próprios administradores, como também permite que se obtenham os recursos mais depressa, e de forma mais segura. Esta meta é alcançável através do uso de uma framework de gestão de cloud, cujo objectivo é assistir na administração da infraestrutura computacional de um departamento. Esta dissertação tem como objectivo fornecer uma avaliação crítica da adequação de três frameworks de gestão de cloud, avaliar os requisitos necessários para uma cloud privada no DI-FCT-NOVA, e identificar que funcionalidades da framework selecionada podem ser utilizadas para a satisfação dos requisitos indicados. O objectivo final é dese- nhar e instalar a framework selecionada no DI-FCT-NOVA, oferecendo assim uma cloud privada de última geração, capaz de responder adequadamente às necessidades dos seus utilizadores - docentes, investigadores e estudantes

Self-healing trans-cloud applications.

Trans-cloud applications consist of multiple interacting components deployed across different cloud providers and at different service layers (IaaS and PaaS). In such complex deployment scenarios, fault handling and recovery need to deal with heterogeneous cloud offerings and to take into account inter-component dependencies. We propose a methodology for self-healing trans-cloud applications from failures occurring in application components or in the cloud services hosting them, both during deployment and while they are being operated. The proposed methodology enables reducing the time application components rely on faulted services, hence residing in “unstable” states where they can suddenly fail in cascade or exhibit erroneous behaviour. We also present an open-source prototype illustrating the feasibility of our proposal, which we have exploited to carry out an extensive evaluation based on controlled experiments and monkey testing.Open access funding provided by Universitá di Pisa within the CRUI-CARE Agreemen

An architecture for a heterogeneous private IaaS management system

Cloud computing and, more particularly, private IaaS, is seen as a mature technology with a myriad solutions tochoose from. However, this disparity of solutions and products has instilled in potential adopters the fear of vendor and data lock-in. Several competing and incompatible interfaces and management styles have given even more voice to these fears. On top of this, cloud users might want to work with several solutions at the same time, an integration that is difficult to achieve in practice. In this paper, we propose a management architecture that tries to tackle these problems; it offers a common way of managing several cloud solutions, and an interface that can be tailored to the needs of the user. This management architecture is designed in a modular way, and using a generic information model. We have validated our approach through the implementation of the components needed for this architecture to support a sample private IaaS solution: OpenStac

Live-Migration in Cloud Computing Environment

O tráfego global de IP aumentou cinco vezes nos últimos cinco anos, e prevê-se que crescerá três vezes nos próximos cinco. Já para o período de 2013 a 2018, anteviu-se que o total do tráfego de IP iria aumentar a sua taxa composta de crescimento anual (CAGR) em, aproximadamente, 3.9 vezes. Assim, os Prestadores de Serviços estão a sofrer com este acréscimo exponencial, que é proveniente do número abismal de dispositivos e utilizadores que estão ligados à Internet, bem como das suas exigências por vários recursos e serviços de rede (como por exemplo, distribuição de conteúdo multimédia, segurança, mobilidade, etc.). Mais especificamente, estes estão com dificuldades em: introduzir novos serviços geradores de receitas; e otimizar e adaptar as suas infraestruturas mais caras, centros de processamento de dados, e redes empresariais e de longa distância (COMpuTIN, 2015). Estas redes continuam a ter sérios problemas (no que toca a agilidade, gestão, mobilidade e no tempo despendido para se adaptarem), que não foram corrigidos até ao momento. Portanto, foram propostos novos modelos de Virtualização de Funções da Rede (NFV) e tecnologias de Redes de Software Definidos (SDN) para solucionar gastos operacionais e de capital não otimizado, e limitações das redes (Lopez, 2014, Hakiri and Berthou, 2015). Para se ultrapassar tais adversidades, o Instituto Europeu de Normas de Telecomunicações (ETSI) e outras organizações propuseram novas arquiteturas de rede. De acordo com o ETSI, a NFV é uma técnica emergente e poderosa, com grande aplicabilidade, e com o objetivo de transformar a maneira como os operadores desenham as redes. Isto é alcançado pela evolução da tecnologia padrão de virtualização TI, de forma a consolidar vários tipos de equipamentos de redes como: servidores de grande volume, routers, switches e armazenamento (Xilouris et al., 2014). Nesta dissertação, foram usadas as soluções mais atuais de SDN e NFV, de forma a produzir um caso de uso que possa solucionar o crescimento do tráfego de rede e a excedência da sua capacidade máxima. Para o desenvolvimento e avalização da solução, foi instalada a plataforma de computação na nuvem OpenStack, de modo a implementar, gerir e testar um caso de uso de Live Migration.Global IP traffic has increased fivefold over the past five years, and will continue increasing threefold over the next five years. The overall IP traffic will grow at a compound annual growth rate (CAGR) nearly 3.9-fold from 2013 to 2018. Service Providers are experiencing the exponential growth of IP traffic that comes from the incredible increased number of devices and users who are connected to the internet along with their demands for various resources and network services like multimedia content distribution, security, mobility and else. Therefore, Service Providers are finding difficult to introduce new revenue generating services, optimize and adapt their expensive infrastructures, data centers, wide-area networks and enterprise networks (COMpuTIN, 2015). The networks continue to have serious known problems, such as, agility, manageability, mobility and time-to-application that have not been successfully addressed so far. Thus, novel Network Function Virtualization (NFV) models and Software-defined Networking (SDN) technologies have been proposed to solve the non-optimal capital and operational expenditures and network’s limitations (Lopez, 2014, Hakiri and Berthou, 2015). In order to solve these issues, the European Telecommunications Standards Institute (ETSI) and other standard organizations are proposing new network architecture approaches. According to ETSI, The Network Functions Virtualization is a powerful emerging technique with widespread applicability, aiming to transform the way that network operators design networks by evolving standard IT virtualization technology to consolidate many network equipment types: high volume servers, routers, switches and storage (Xilouris et al., 2014). In this thesis, the current Software-Defined Networking (SDN) and Network Function Virtualization (NFV) solutions were used in order to make a use case that can address the increasing of network traffic and exceeding its maximum capacity. To develop and evaluate the solution, OpenStack cloud computing platform was installed in order to deploy, manage and test a Live-Migration use-case

An infrastructure service recommendation system for cloud applications with real-time QoS requirement constraints

The proliferation of cloud computing has revolutionized the hosting and delivery of Internet-based application services. However, with the constant launch of new cloud services and capabilities almost every month by both big (e.g., Amazon Web Service and Microsoft Azure) and small companies (e.g., Rackspace and Ninefold), decision makers (e.g., application developers and chief information officers) are likely to be overwhelmed by choices available. The decision-making problem is further complicated due to heterogeneous service configurations and application provisioning QoS constraints. To address this hard challenge, in our previous work, we developed a semiautomated, extensible, and ontology-based approach to infrastructure service discovery and selection only based on design-time constraints (e.g., the renting cost, the data center location, the service feature, etc.). In this paper, we extend our approach to include the real-time (run-time) QoS (the end-to-end message latency and the end-to-end message throughput) in the decision-making process. The hosting of next-generation applications in the domain of online interactive gaming, large-scale sensor analytics, and real-time mobile applications on cloud services necessitates the optimization of such real-time QoS constraints for meeting service-level agreements. To this end, we present a real-time QoS-aware multicriteria decision-making technique that builds over the well-known analytic hierarchy process method. The proposed technique is applicable to selecting Infrastructure as a Service (IaaS) cloud offers, and it allows users to define multiple design-time and real-time QoS constraints or requirements. These requirements are then matched against our knowledge base to compute the possible best fit combinations of cloud services at the IaaS layer. We conducted extensive experiments to prove the feasibility of our approach

Interoperability in the Heterogeneous Cloud Environment: A Survey of Recent User-centric Approaches

© 2016 Copyright held by the owner/author(s). Cloud computing provides users the ability to access shared, online computing resources. However, providers often offer their own proprietary applications, interfaces, APIs and infrastructures, resulting in a heterogeneous cloud environment. This heterogeneous environment makes it difficult for users to change cloud service providers; exploring capabilities to support the automated migration from one provider to another is an active, open research area. Many standards bodies (IEEE, NIST, DMTF and SNIA), industry (middleware) and academia have been pursuing approaches to reduce the impact of vendor lock-in by investigating the cloud migration problem at the level of the VM. However, the migration downtime, decoupling VM from underlying systems and security of live channels remain open issues. This paper focuses on analysing recently proposed live, cloud migration approaches for VMs at the infrastructure level in the cloud architecture. The analysis reveals issues with flexibility, performance, and security of the approaches, including additional loads to the CPU and disk I/O drivers of the physical machine where the VM initially resides. The next steps of this research are to develop and evaluate a new approach LibZam (Libya Zamzem) that will work towards addressing the identified limitations