近年來，雲端運算中的軟體即服務(Software as Service，SaaS)穩健與快速地成長。SaaS服務提供者在建置服務的過程中，無不希望盡可能地讓租戶共享資源，避免租戶擁有特殊資源，需要獨立維護，以降低維護營運成本。另一方面，也要能讓租戶們擁有一定程度的客製化能力，以製做出屬於租戶私有之服務邏輯。因此如何讓租戶在共有一切資源的前提下，又能提供客製化能力，將是SaaS服務提供者的一大課題。本研究所提出的中介軟體框架將在共用硬體及資料庫與單一應用程式的共用架構下，採用Force.com Universal Table資料架構，並提供三大特色功能，Tenant Aware、Data Access以及Tenant Customizability，來解決隔離性、存取Force.com Universal Table資料架構以及提供租戶客製化能力三大議題。透過此中介軟體框架應可幫助SaaS提供者，建置出一個資源共享、租戶具有客製能力與維護性高的多租戶雲端軟體服務。 / In recent years, Software as a service (SaaS), the service model of cloud computing, has been growing healthy and rapidly. When SaaS providers build service, they want tenants to share same resources, and not to have its own special resource which will cause providers to maintain it separately. SaaS providers want tenants sharing the same resources to reduce maintenance cost. But the current trend is to provide the customizability to tenants for customizing its own service. How to share resources under the premise of providing customizability to tenants will be the main challenge to SaaS providers. In this thesis, we propose a middleware framework based on shared hardware、database with a single application instance. Our framework will use the Force.com Universal Table schema as the foundation. The key features of our framework are Tenant Aware、Data Access and Tenant Customizability. These features will address the issues of isolating tenants, accessing the Force.com Universal Table schema and providing customizability to tenants. This middleware framework will help SaaS providers to build a resource-sharing, customizable multi-tenant SaaS with lower maintenance cost.

[pt] A computação na nuvem vem modificando a maneira pela qual os usuários acessam e usufruem de serviços computacionais. Um sistema gerenciador de banco de dados é um dos principais recursos deste novo ambiente de trabalho. Entretanto, os grandes volumes de dados devem ser adequadamente gerenciados e disponibilizados, de acordo com as oscilações das cargas de trabalho e em função de novos parâmetros existentes. Pelas dimensões do problema neste novo ambiente da nuvem, não há como dispor de um DBA que consiga, manualmente, administrar, manter disponibilidade e desempenho de maneira aceitável. Em particular, há necessidade de sintonia fina (tuning) automática pois o sistema na nuvem deve cumprir requisitos contratuais de operação e, para o usuário, deve-se oferecer recursos como se fossem ilimitados ao mesmo tempo que com excelente desempenho. Nesta dissertação são explicitadas e comparadas as atividades de (auto) sintonia fina em SGBDs que operam em ambientes convencionais e em ambientes de nuvem. Enfatizam-se as diferenças observadas na visão do provedor do serviço de nuvem e dos usuários em um contexto de DBaaS. Nesta pesquisa será proposta uma nova extensão da ontologia de domínio desenvolvida e aprimorada por [Almeida, 2013] e [Oliveira, 2015], a fim de abranger a sintonia fina em banco de dados na nuvem. / [en] Cloud computing is changing the way users access and benefit from computer services. A database manager is one of the main features of this new working environment. However, large volumes of data must be properly managed and made available, according to the fluctuations in workloads and function of new and existing parameters. Because of dimensions problems in this new cloud environment, it is very difficult to have a DBA who can manually manage, maintain availability and performance acceptably. In particular, the necessity of a tuning process automatic in the cloud system to meet contractual operation requirements and the necessity of offering to the user resources as if they were unlimited while with excellent performance. This thesis explains and compares the activities of (self)-tuning database systems operating in conventional and cloud environments, emphasizing the differences observed in the cloud service provider s view and users in a context of DBaaS. In particular, it is proposed to extend of tuning ontology in order to automate actions to tuning the Database as a Service.

This thesis discusses the new way of delivering IT services over the Internet widely known as cloud computing. In its opening part, cloud computing is put into a historical context of the evolution of enterprise computing, and the dominant issues the IT department faces today are mentioned. Further, the paper deals with several components that make up the architecture of cloud computing and reviews the benefits and drawbacks an enterprise can have while it adopts this new model. One of the primary aims of this thesis is to identify the impact of the technology trends on cloud computing. The thesis brings together four major computing trends, namely virtualization, multi-tenant architecture, service-oriented architecture and grid computing. Another aim is to focus on two trends related to IT infrastructure that will lead to fundamental changes in IT industry. The first of them is the emergence of extremely large-scale data centers at low cost locations, which can serve tremendous amount of customers and achieve considerable economies of scale. The second trend this paper points out is the shift from multi-purpose all-in-one computers into a wide range of mobile devices dedicated to a specific user's needs. The last aim of this thesis is to clarify the economic impact of cloud computing in terms of costs and changes in business models. The thesis concludes by evaluating the current adoption and predicting the future trend of cloud computing.

Made available in DSpace on 2016-06-02T19:06:22Z (GMT). No. of bitstreams: 1 6616.pdf: 3224245 bytes, checksum: 3bea5c064e483543e0961a78c51613d2 (MD5) Previous issue date: 2014-10-20 / Software as a Service (SaaS) represent a form of software distribution on demand and accessible via the Internet. The development of SaaS enables service users (tenants) to benefit from the low cost of deployment and maintenance. The Multi-Tenant (MT) architecture is often used in the development of SaaS, it allows the sharing of software and hardware resources, providing cost savings to the costumers and the service provider. A challenge that the SaaS developer has is to keep sharing the instance of the software in scenarios with tenants who have differing needs. In this project, to address the variability of tenants in SaaS MT were set some patterns, based on Software Product Lines techniques for customizing user interfaces, data, processes and permissions. A framework called FoSaaS (Framework of Software as a Service) has also been developed to support the use of patterns, providing support to developers in SaaS MT coding. In addition to allowing the customization of SaaS MT, experiments in this project indicated that patterns improve reuse, quality and productivity in developed SaaS MT. The applicability of the patterns was evidenced through real projects in developing commercial applications. / Softwares como um Serviço (SaaS) representam uma forma de distribuição de software sob demanda e acessíveis via Internet. O desenvolvimento de SaaS possibilita aos consumidores do serviço (tenants) se beneficiarem do baixo custo de implantação e manutenção. A arquitetura Multi-Tenant (MT) é frequentemente utilizada no desenvolvimento de SaaS, pois permite o compartilhamento de recursos de software e hardware, proporcionando a redução de custos ao consumidor e ao fornecedor do serviço. Um desafio que o desenvolvedor de SaaS tem é o de manter o compartilhamento da instância do software em cenários com tenants que possuem necessidades divergentes. Neste projeto, para tratar a variabilidade dos tenants em SaaS MT foram criados alguns padrões, com base em técnicas de linhas de produtos de software, para customização de interfaces de usuários, dados, processos e permissões. Um framework denominado FoSaaS (Framework of Software as a Service) também foi desenvolvido para apoiar o uso dos padrões criados fornecendo apoio aos desenvolvedores na codificação de SaaS MT. Além de permitir a customização de SaaS MT, experimentos realizados neste projeto indicaram que os padrões melhoram o reúso, a qualidade e a produtividade dos SaaS MT desenvolvidos. A aplicabilidade dos padrões foi evidenciada por meio da realização de projetos reais no desenvolvimento de aplicações comerciais.

傳統展演中，觀眾和表演者被視為是兩個獨立的個體，表演者與表演者間及表演者與觀眾間互動不多，若使用穿戴式裝置結合科技與藝術的「虛實互動數位展演」，能協助營造現場的互動氣氛，是既新穎又富有創意的表演模式，還能結合故事劇情與觀眾互動，此種互動的情境氛圍，會比一般的資訊傳遞更容易讓觀眾有所感受。 而目前許多表演活動的展演特效系統，都是由特效控制技術人員根據展演人員的動作與節目進程來呈現。如果由展演人員自行操作、建置與管理的話，便需要瞭解特效控制的相關技術，此外也需要和技術人員互相溝通與合作。而彼此觀念、資訊與背景的不同，難免容易造成控制上的失誤、延遲或是溝通不良導致表演效果不佳以致於觀眾不好的視聽感受。基於上述問題，本研究將設計一個基於多租戶概念的雲端互動展演系統整合平台，展演人員只需透過網路連結至展演系統網站，配合連網感應器的穿戴式裝置，不需自行建置、管理系統平台，登入後可依個人需求使用直覺圖形化邏輯編輯器，使用滑鼠拖拉，控制需求，不需繁複的技術教學訓練，便根據穿戴式裝置回傳的感測訊號做出響應式的展演效果變化，達到展演人員可簡單好上手地自行操作展演特效系統，減少與特效控制技術人員合作上的失誤。 / In traditional performance art, viewers and performers are regarded as two independent individuals. There is less interaction between performers and performers, performers and audiences. If wearable devices are used in the "cyber-physical interactive digital performance art", it can help create an interactive atmosphere in the scene. It is a creative, innovative mode of performance, and it also creates a combination between scenario and the interaction of the audiences. The interactive atmosphere is easier for the audience to be affected than ordinary information transmission. Currently, many special effects are presented by the technical staff. They are based on the performers and progression of show. If the special effects are managed by the performer-selves, they need to understand the relative technologies. In addition, they have to cooperate and communicate with technical staff. However, the difference of concept and background between each other, it's hard to avoid the mistake, delay, or misunderstanding of control. It may cause that the poor performance bring audience about the bad auditory and visual feeling. According to above issues, this study will design and implement a multi-tenant cloud platform for cyber-physical interactive performance art. The performers just connect to the performance art system website via the Internet, with the wearable device, and they do not need to set up and manage system platform by themselves. They log in the website, with the GUI editor, and use mouse to control demand. Without complex technical training, the variety of special effects are presented which based on the wearable device’s signal. We suppose that the platform makes the performers operate special effects system by themselves simply and easily. It also reduces the misunderstanding with the technical staff.

Queueing theory is widely used in practical queuing applications. It can be applied for specific models of queuing systems, especially the ones that follow the Markovian property. Its purpose is to predict system behaviour in order to be used for performance optimization. In this case study, it was used to evaluate an extended queuing model with agents serving multiple queues. The purpose was to try to capture more variability and input factors into the theoretical model and test its applicability on more extended models. The main objective was to use relevant queuing theory models to estimate the wait time using real contact center data. Different from the theoretical model, the service rates of the system model depended on how many queues an agent served concurrently, which increased the complexity of the model. The obtained results demonstrated some limitations that made the models too restrictive to be applied to a model with multi-skilled agents that were not equally available. Moreover, it was shown that heuristical approaches might be more suitable for more complex queuing systems that are not covered in queueing theory models. / Köteori används i stor utsträckning i praktiska kö-applikationer. Den kan tillämpas för specifika modeller av kö-system, speciellt de som följer Markovegenskapen. Dess syfte är att förutse systembeteende för att kunna användas för prestandaoptimering. I denna fallstudie användes den för att utvärdera en utökad kömodell med agenter som betjänade flera köer. Syftet var att försöka fånga mer variabilitet och inputfaktorer i den teoretiska modellen och testa dess tillämplighet för mer utökade modeller. Huvudmålet var att använda relevanta kö-teorimodeller för att estimera väntetiden med användning av riktiga contact center data. Till skillnad från den teoretiska modellen, betjäningsintensiteten för systemmodellen berodde på hur många köer en agent betjänade samtidigt, vilket ökade komplexiteten av modellen. De erhållna resultaten visade begränsningar som gjorde modellen för restriktiv för att appliceras på en modell med fler-kvalificerade agenter som inte var lika tillgängliga. Utöver detta så visade det sig att heuristiska metoder kan vara mer lämpliga för mer komplicerade system som inte täcks av kö-teori modeller.