821 resultados para cloud computing, hypervisor, virtualizzazione, live migration, infrastructure as a service
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Uno dei temi più discussi ed interessanti nel mondo dell’informatica al giorno d’oggi è sicuramente il Cloud Computing. Nuove organizzazioni che offrono servizi di questo tipo stanno nascendo ovunque e molte aziende oggi desiderano imparare ad utilizzarli, migrando i loro centri di dati e le loro applicazioni nel Cloud. Ciò sta avvenendo anche grazie alla spinta sempre più forte che stanno imprimendo le grandi compagnie nella comunità informatica: Google, Amazon, Microsoft, Apple e tante altre ancora parlano sempre più frequentemente di Cloud Computing e si stanno a loro volta ristrutturando profondamente per poter offrire servizi Cloud adeguandosi così a questo grande cambiamento che sta avvenendo nel settore dell’informatica. Tuttavia il grande movimento di energie, capitali, investimenti ed interesse che l’avvento del Cloud Computing sta causando non aiuta a comprendere in realtà che cosa esso sia, al punto tale che oggi non ne esiste ancora una definizione univoca e condivisa. La grande pressione inoltre che esso subisce da parte del mondo del mercato fa sì che molte delle sue più peculiari caratteristiche, dal punto di vista dell’ingegneria del software, vengano nascoste e soverchiate da altre sue proprietà, architetturalmente meno importanti, ma con un più grande impatto sul pubblico di potenziali clienti. L’obbiettivo che ci poniamo con questa tesi è quindi quello di esplorare il nascente mondo del Cloud Computing, cercando di comprenderne a fondo le principali caratteristiche architetturali e focalizzando l’attenzione in particolare sullo sviluppo di applicazioni in ambiente Cloud, processo che sotto alcuni aspetti si differenzia molto dallo sviluppo orientato ad ambienti più classici. La tesi è così strutturata: nel primo capitolo verrà fornita una panoramica sul Cloud Computing nella quale saranno date anche le prime definizioni e verranno esposti tutti i temi fondamentali sviluppati nei capitoli successivi. Il secondo capitolo costituisce un approfondimento su un argomento specifico, quello dei Cloud Operating System, componenti fondamentali che permettono di trasformare una qualunque infrastruttura informatica in un’infrastruttura Cloud. Essi verranno presentati anche per mezzo di molte analogie con i classici sistemi operativi desktop. Con il terzo capitolo ci si addentra più a fondo nel cuore del Cloud Computing, studiandone il livello chiamato Infrastructure as a Service tramite un esempio concreto di Cloud provider: Amazon, che fornisce i suoi servizi nel progetto Amazon Web Services. A questo punto, più volte nel corso della trattazione di vari temi saremo stati costretti ad affrontare le problematiche relative alla gestione di enormi moli di dati, che spesso sono il punto centrale di molte applicazioni Cloud. Ci è parso quindi importante approfondire questo argomento in un capitolo appositamente dedicato, il quarto, supportando anche in questo caso la trattazione teorica con un esempio concreto: BigTable, il sistema di Google per la gestione della memorizzazione di grandi quantità di dati. Dopo questo intermezzo, la trattazione procede risalendo lungo i livelli dell’architettura Cloud, ricalcando anche quella che è stata l’evoluzione temporale del Cloud Computing: nel quinto capitolo, dal livello Infrastructure as a Service si passa quindi a quello Platform as a Service, tramite lo studio dei servizi offerti da Google Cloud Platform. Il sesto capitolo costituisce invece il punto centrale della tesi, quello che ne soddisfa l’obbiettivo principale: esso contiene infatti uno studio approfondito sullo sviluppo di applicazioni orientate all’ambiente Cloud. Infine, il settimo capitolo si pone come un ponte verso possibili sviluppi futuri, analizzando quali sono i limiti principali delle tecnologie, dei modelli e dei linguaggi che oggi supportano il Cloud Computing. In esso viene proposto come possibile soluzione il modello ad attori; inoltre viene anche presentato il framework Orleans, che Microsoft sta sviluppando negli ultimi anni con lo scopo appunto di supportare lo sviluppo di applicazioni in ambiente Cloud.
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Manufacturing industry has been always facing challenge to improve the production efficiency, product quality, innovation ability and struggling to adopt cost-effective manufacturing system. In recent years cloud computing is emerging as one of the major enablers for the manufacturing industry. Combining the emerged cloud computing and other advanced manufacturing technologies such as Internet of Things, service-oriented architecture (SOA), networked manufacturing (NM) and manufacturing grid (MGrid), with existing manufacturing models and enterprise information technologies, a new paradigm called cloud manufacturing is proposed by the recent literature. This study presents concepts and ideas of cloud computing and cloud manufacturing. The concept, architecture, core enabling technologies, and typical characteristics of cloud manufacturing are discussed, as well as the difference and relationship between cloud computing and cloud manufacturing. The research is based on mixed qualitative and quantitative methods, and a case study. The case is a prototype of cloud manufacturing solution, which is software platform cooperated by ATR Soft Oy and SW Company China office. This study tries to understand the practical impacts and challenges that are derived from cloud manufacturing. The main conclusion of this study is that cloud manufacturing is an approach to achieve the transformation from traditional production-oriented manufacturing to next generation service-oriented manufacturing. Many manufacturing enterprises are already using a form of cloud computing in their existing network infrastructure to increase flexibility of its supply chain, reduce resources consumption, the study finds out the shift from cloud computing to cloud manufacturing is feasible. Meanwhile, the study points out the related theory, methodology and application of cloud manufacturing system are far from maturity, it is still an open field where many new technologies need to be studied.
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Questo documento affronta le novità ed i vantaggi introdotti nel mondo delle reti di telecomunicazioni dai paradigmi di Software Defined Networking e Network Functions Virtualization, affrontandone prima gli aspetti teorici, per poi applicarne i concetti nella pratica, tramite casi di studio gradualmente più complessi. Tali innovazioni rappresentano un'evoluzione dell'architettura delle reti predisposte alla presenza di più utenti connessi alle risorse da esse offerte, trovando quindi applicazione soprattutto nell'emergente ambiente di Cloud Computing e realizzando in questo modo reti altamente dinamiche e programmabili, tramite la virtualizzazione dei servizi di rete richiesti per l'ottimizzazione dell'utilizzo di risorse. Motivo di tale lavoro è la ricerca di soluzioni ai problemi di staticità e dipendenza, dai fornitori dei nodi intermedi, della rete Internet, i maggiori ostacoli per lo sviluppo delle architetture Cloud. L'obiettivo principale dello studio presentato in questo documento è quello di valutare l'effettiva convenienza dell'applicazione di tali paradigmi nella creazione di reti, controllando in questo modo che le promesse di aumento di autonomia e dinamismo vengano rispettate. Tale scopo viene perseguito attraverso l'implementazione di entrambi i paradigmi SDN e NFV nelle sperimentazioni effettuate sulle reti di livello L2 ed L3 del modello OSI. Il risultato ottenuto da tali casi di studio è infine un'interessante conferma dei vantaggi presentati durante lo studio teorico delle innovazioni in analisi, rendendo esse una possibile soluzione futura alle problematiche attuali delle reti.
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Lunacloud is a cloud service provider with offices in Portugal, Spain, France and UK that focus on delivering reliable, elastic and low cost cloud Infrastructure as a Service (IaaS) solutions. The company currently relies on a proprietary IaaS platform - the Parallels Automation for Cloud Infrastructure (PACI) - and wishes to expand and integrate other IaaS solutions seamlessly, namely open source solutions. This is the challenge addressed in this thesis. This proposal, which was fostered by Eurocloud Portugal Association, contributes to the promotion of interoperability and standardisation in Cloud Computing. The goal is to investigate, propose and develop an interoperable open source solution with standard interfaces for the integrated management of IaaS Cloud Computing resources based on new as well as existing abstraction libraries or frameworks. The solution should provide bothWeb and application programming interfaces. The research conducted consisted of two surveys covering existing open source IaaS platforms and PACI (features and API) and open source IaaS abstraction solutions. The first study was focussed on the characteristics of most popular open source IaaS platforms, namely OpenNebula, OpenStack, CloudStack and Eucalyptus, as well as PACI and included a thorough inventory of the provided Application Programming Interfaces (API), i.e., offered operations, followed by a comparison of these platforms in order to establish their similarities and dissimilarities. The second study on existing open source interoperability solutions included the analysis of existing abstraction libraries and frameworks and their comparison. The approach proposed and adopted, which was supported on the conclusions of the carried surveys, reuses an existing open source abstraction solution – the Apache Deltacloud framework. Deltacloud relies on the development of software driver modules to interface with different IaaS platforms, officially provides and supports drivers to sixteen IaaS platform, including OpenNebula and OpenStack, and allows the development of new provider drivers. The latter functionality was used to develop a new Deltacloud driver for PACI. Furthermore, Deltacloud provides a Web dashboard and REpresentational State Transfer (REST) API interfaces. To evaluate the adopted solution, a test bed integrating OpenNebula, Open- Stack and PACI nodes was assembled and deployed. The tests conducted involved time elapsed and data payload measurements via the Deltacloud framework as well as via the pre-existing IaaS platform API. The Deltacloud framework behaved as expected, i.e., introduced additional delays, but no substantial overheads. Both the Web and the REST interfaces were tested and showed identical measurements. The developed interoperable solution for the seamless integration and provision of IaaS resources from PACI, OpenNebula and OpenStack IaaS platforms fulfils the specified requirements, i.e., provides Lunacloud with the ability to expand the range of adopted IaaS platforms and offers a Web dashboard and REST API for the integrated management. The contributions of this work include the surveys and comparisons made, the selection of the abstraction framework and, last, but not the least, the PACI driver developed.
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In recent years, vehicular cloud computing (VCC) has emerged as a new technology which is being used in wide range of applications in the area of multimedia-based healthcare applications. In VCC, vehicles act as the intelligent machines which can be used to collect and transfer the healthcare data to the local, or global sites for storage, and computation purposes, as vehicles are having comparatively limited storage and computation power for handling the multimedia files. However, due to the dynamic changes in topology, and lack of centralized monitoring points, this information can be altered, or misused. These security breaches can result in disastrous consequences such as-loss of life or financial frauds. Therefore, to address these issues, a learning automata-assisted distributive intrusion detection system is designed based on clustering. Although there exist a number of applications where the proposed scheme can be applied but, we have taken multimedia-based healthcare application for illustration of the proposed scheme. In the proposed scheme, learning automata (LA) are assumed to be stationed on the vehicles which take clustering decisions intelligently and select one of the members of the group as a cluster-head. The cluster-heads then assist in efficient storage and dissemination of information through a cloud-based infrastructure. To secure the proposed scheme from malicious activities, standard cryptographic technique is used in which the auotmaton learns from the environment and takes adaptive decisions for identification of any malicious activity in the network. A reward and penalty is given by the stochastic environment where an automaton performs its actions so that it updates its action probability vector after getting the reinforcement signal from the environment. The proposed scheme was evaluated using extensive simulations on ns-2 with SUMO. The results obtained indicate that the proposed scheme yields an improvement of 10 % in detection rate of malicious nodes when compared with the existing schemes.
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The MAP-i Doctoral Program of the Universities of Minho, Aveiro and Porto.
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This thesis discusses the opportunities and challenges of the cloud computing technology in healthcare information systems by reviewing the existing literature on cloud computing and healthcare information system and the impact of cloud computing technology to healthcare industry. The review shows that if problems related to security of data are solved then cloud computing will positively transform the healthcare institutions by giving advantage to the healthcare IT infrastructure as well as improving and giving benefit to healthcare services. Therefore, this thesis will explore the opportunities and challenges that are associated with cloud computing in the context of Finland in order to help the healthcare organizations and stakeholders to determine its direction when it decides to adopt cloud technology on their information systems.
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Video transcoding refers to the process of converting a digital video from one format into another format. It is a compute-intensive operation. Therefore, transcoding of a large number of simultaneous video streams requires a large amount of computing resources. Moreover, to handle di erent load conditions in a cost-e cient manner, the video transcoding service should be dynamically scalable. Infrastructure as a Service Clouds currently offer computing resources, such as virtual machines, under the pay-per-use business model. Thus the IaaS Clouds can be leveraged to provide a coste cient, dynamically scalable video transcoding service. To use computing resources e ciently in a cloud computing environment, cost-e cient virtual machine provisioning is required to avoid overutilization and under-utilization of virtual machines. This thesis presents proactive virtual machine resource allocation and de-allocation algorithms for video transcoding in cloud computing. Since users' requests for videos may change at di erent times, a check is required to see if the current computing resources are adequate for the video requests. Therefore, the work on admission control is also provided. In addition to admission control, temporal resolution reduction is used to avoid jitters in a video. Furthermore, in a cloud computing environment such as Amazon EC2, the computing resources are more expensive as compared with the storage resources. Therefore, to avoid repetition of transcoding operations, a transcoded video needs to be stored for a certain time. To store all videos for the same amount of time is also not cost-e cient because popular transcoded videos have high access rate while unpopular transcoded videos are rarely accessed. This thesis provides a cost-e cient computation and storage trade-o strategy, which stores videos in the video repository as long as it is cost-e cient to store them. This thesis also proposes video segmentation strategies for bit rate reduction and spatial resolution reduction video transcoding. The evaluation of proposed strategies is performed using a message passing interface based video transcoder, which uses a coarse-grain parallel processing approach where video is segmented at group of pictures level.
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SOA (Service Oriented Architecture), workflow, the Semantic Web, and Grid computing are key enabling information technologies in the development of increasingly sophisticated e-Science infrastructures and application platforms. While the emergence of Cloud computing as a new computing paradigm has provided new directions and opportunities for e-Science infrastructure development, it also presents some challenges. Scientific research is increasingly finding that it is difficult to handle “big data” using traditional data processing techniques. Such challenges demonstrate the need for a comprehensive analysis on using the above mentioned informatics techniques to develop appropriate e-Science infrastructure and platforms in the context of Cloud computing. This survey paper describes recent research advances in applying informatics techniques to facilitate scientific research particularly from the Cloud computing perspective. Our particular contributions include identifying associated research challenges and opportunities, presenting lessons learned, and describing our future vision for applying Cloud computing to e-Science. We believe our research findings can help indicate the future trend of e-Science, and can inform funding and research directions in how to more appropriately employ computing technologies in scientific research. We point out the open research issues hoping to spark new development and innovation in the e-Science field.
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The extensive use of cloud computing in educational institutes around the world brings unique challenges for universities. Some of these challenges are due to clear differences between Europe and Middle East universities. These differences stem from the natural variation between people. Cloud computing has created a new concept to deal with software services and hardware infrastructure. Some benefits are immediately gained, for instance, to allow students to share their information easily and to discover new experiences of the education system. However, this introduces more challenges, such as security and configuration of resources in shared environments. Educational institutes cannot escape from these challenges. Yet some differences occur between universities which use cloud computing as an educational tool or a form of social connection. This paper discusses some benefits and limitations of using cloud computing and major differences in using cloud computing at universities in Europe and the Middle East, based on the social perspective, security and economics concepts, and personal responsibility.
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Cloud computing innebär användning av datorresurser som är tillgängliga via ett nätverk, oftast Internet och är ett område som har vuxit fram i snabb takt under de senaste åren. Allt fler företag migrerar hela eller delar av sin verksamhet till molnet. Sogeti i Borlänge har behov av att migrera sina utvecklingsmiljöer till en molntjänst då drift och underhåll av dessa är kostsamma och tidsödande. Som Microsoftpartners vill Sogeti använda Microsoft tjänst för cloud computing, Windows Azure, för detta syfte. Migration till molnet är ett nytt område för Sogeti och de har inga beskrivningar för hur en sådan process går till. Vårt uppdrag var att utveckla ett tillvägagångssätt för migration av en IT-lösning till molnet. En del av uppdraget blev då att kartlägga cloud computing, dess beståndsdelar samt vilka för- och nackdelar som finns, vilket har gjort att vi har fått grundläggande kunskap i ämnet. För att utveckla ett tillvägagångssätt för migration har vi utfört flera migrationer av virtuella maskiner till Windows Azure och utifrån dessa migrationer, litteraturstudier och intervjuer dragit slutsatser som mynnat ut i ett generellt tillvägagångssätt för migration till molnet. Resultatet har visat att det är svårt att göra en generell men samtidigt detaljerad beskrivning över ett tillvägagångssätt för migration, då scenariot ser olika ut beroende på vad som ska migreras och vilken typ av molntjänst som används. Vi har dock utifrån våra erfarenheter från våra migrationer, tillsammans med litteraturstudier, dokumentstudier och intervjuer lyft vår kunskap till en generell nivå. Från denna kunskap har vi sammanställt ett generellt tillvägagångssätt med större fokus på de förberedande aktiviteter som en organisation bör genomföra innan migration. Våra studier har även resulterat i en fördjupad beskrivning av cloud computing. I vår studie har vi inte sett att någon tidigare har beskrivit kritiska framgångsfaktorer i samband med cloud computing. I vårt empiriska arbete har vi dock identifierat tre kritiska framgångsfaktorer för cloud computing och i och med detta täckt upp en del av kunskapsgapet där emellan.
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Este estudo visa desenvolver uma investigação exploratória e quali-quantitativa, a cerca da representação social do Cloud Computing, na visão dos profissionais de TI brasileiros. Objetiva expor quais as percepções dos usuários da área de TI a respeito do paradigma computacional Cloud Computing. Para suportar o estudo teórico, foram coletados dados empíricos, por meio de questionários online respondidos por 221 profissionais da área de TI. Com o uso da técnica de evocação de palavras e da teoria da representação social (TRS), os dados coletados foram sumarizados. Após o tratamento dos dados mediante o uso da técnica do quadro de quatro casas de Vergès, obteve-se como resultado, a identificação do núcleo central e do sistema periférico da representação social do Cloud Computing. Por fim, os dados foram analisados utilizando-se as análises implicativa e de conteúdo, de forma a que todas as informações fossem abstraídas para melhor interpretação do tema. Obteve-se como resultado, que o núcleo central da representação social do Cloud Computing é composto pelas seguintes palavras “Nuvem”, “Armazenamento”, “Disponibilidade”, “Internet”, “Virtualização” e “Segurança”. Por sua vez, as palavras identificadas como parte do sistema periférico da representação social do Cloud Computing foram: “Compartilhamento”, “Escalabilidade” e ”Facilidade”. Os resultados permitem compreender qual percepção dos profissionais de TI a respeito deste paradigma tecnológico e sua correlação com o referencial teórico abordado. Tais informações e percepções podem auxiliar a tornar o não familiar em familiar, ou seja, compreender como o Cloud Computing é representado, visto e, finalmente, reconhecido pelos profissionais da área de TI.
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Includes bibliography.