Cost-aware real-time divisible loads scheduling in cloud computing

Cloud computing has become an important alternative for solving large scale resource intensive problems in science, engineering, and analytics. Resource management play an important role in improving the quality of service (QoS). This paper is concerned with the investigation of scheduling strategies for divisible loads with deadlines constraints upon heterogeneous processors in a cloud computing environment. The workload allocation approach presents in this paper is using Divisible Load Theory (DLT). It is based on the fact that the computation can be partitioned into some arbitrary sizes and each partition can be processed independently of each other. Through series of simulation against the baseline strategies, it can be found that the worker selection order in the service pool and the amount of fraction load assigned to each of them have significant effects on the total computation cost.Keywords: Cloud computing, Divisible Load Theory (DLT), Cost, Quality-of-service (QoS

Cost-based multi-QoS job scheduling using divisible load theory in cloud computing

The advent of cloud computing as a new model of service provisioning in distributed systems, encourages researchers to investigate its benefits and drawbacks in executing scientific applications such as workflows. In this research, we attempt to investigate the use of a Divisible Load Theory (DLT) to design efficient strategies to minimize the overall processing time for scheduling jobs in compute cloud environments. We consider homogeneous processors in our analysis and we derive a closed-form solution for the load fractions to be assigned to each processors. Our analysis also attempts to schedule the jobs such a way that cloud provider can gain maximum benefit for his service and Quality of Service (QoS) requirement user’s job. Finally, we quantify the performance of the strategies via rigorous simulation studies

Dynamic collaboration and secure access of services in multi-cloud environments

The cloud computing services have gained popularity in both public and enterprise domains and they process a large amount of user data with varying privacy levels. The increasing demand for cloud services including storage and computation requires new functional elements and provisioning schemes to meet user requirements. Multi-clouds can optimise the user requirements by allowing them to choose best services from a large number of services offered by various cloud providers as they are massively scalable, can be dynamically configured, and delivered on demand with large-scale infrastructure resources. A major concern related to multi-cloud adoption is the lack of models for them and their associated security issues which become more unpredictable in a multi-cloud environment. Moreover, in order to trust the services in a foreign cloud users depend on their assurances given by the cloud provider but cloud providers give very limited evidence or accountability to users which offers them the ability to hide some behaviour of the service. In this thesis, we propose a model for multi-cloud collaboration that can securely establish dynamic collaboration between heterogeneous clouds using the cloud on-demand model in a secure way. Initially, threat modelling for cloud services has been done that leads to the identification of various threats to service interfaces along with the possible attackers and the mechanisms to exploit those threats. Based on these threats the cloud provider can apply suitable mechanisms to protect services and user data from these threats. In the next phase, we present a lightweight and novel authentication mechanism which provides a single sign-on (SSO) to users for authentication at runtime between multi-clouds before granting them service access and it is formally verified. Next, we provide a service scheduling mechanism to select the best services from multiple cloud providers that closely match user quality of service requirements (QoS). The scheduling mechanism achieves high accuracy by providing distance correlation weighting mechanism among a large number of services QoS parameters. In the next stage, novel service level agreement (SLA) management mechanisms are proposed to ensure secure service execution in the foreign cloud. The usage of SLA mechanisms ensures that user QoS parameters including the functional (CPU, RAM, memory etc.) and non-functional requirements (bandwidth, latency, availability, reliability etc.) of users for a particular service are negotiated before secure collaboration between multi-clouds is setup. The multi-cloud handling user requests will be responsible to enforce mechanisms that fulfil the QoS requirements agreed in the SLA. While the monitoring phase in SLA involves monitoring the service execution in the foreign cloud to check its compliance with the SLA and report it back to the user. Finally, we present the use cases of applying the proposed model in scenarios such as Internet of Things (IoT) and E-Healthcare in multi-clouds. Moreover, the designed protocols are empirically implemented on two different clouds including OpenStack and Amazon AWS. Experiments indicate that the proposed model is scalable, authentication protocols result only in a limited overhead compared to standard authentication protocols, service scheduling achieves high efficiency and any SLA violations by a cloud provider can be recorded and reported back to the user.My research for first 3 years of PhD was funded by the College of Engineering and Technology

Modelo de aceptación y uso del cloud computing: un análisis realizado en el ámbito empresarial

La economía digital está contribuyendo de forma decisiva al impulso de la competitividad del sector productivo de una organización, pero este hecho implica migrar de una economía con un escaso grado de adopción de las Tecnologías de la Información, a otra donde es común y normal aprovecharlas en todas las actividades económicas, culturales y sociales. Esa adopción tecnológica genera incrementos en la productividad y en la competitividad de las empresas, organizaciones y administraciones, contribuyendo así a la generación de bienestar y de mayores oportunidades de progreso. Contribuir y profundizar en estudios relacionados con estos modelos de adopción y su contribución a la mejora de competitividad de una organización es el objetivo de este trabajo de investigación. Actualmente, los sistemas cloud computing o la computación en la nube son una de las alternativas más reales para conseguir mejorar esa competitividad, pero no sólo como tecnología de la información, sino como un nuevo modelo económico de aprovechamiento de los recursos, de explotación de las aplicaciones y de los datos o de prestar servicios empresariales. Esta investigación trata de estudiar y ahondar en la evolución de esta todavía reciente tecnología, su aplicabilidad a medio y largo plazo, así como en encontrar la fórmula que permita encontrar su mejor modelo de adopción tecnológico en una organización. Normalmente estos trabajos están centrados en aspectos puramente tecnológicos, sin intentar estudiar su repercusión en las organizaciones. Este trabajo de investigación trata otro enfoque que permita optimizar y adaptar estas tecnologías a la realidad de nuestro tejido productivo. Los resultados de esta investigación reflejan cuales son los factores críticos a tener en cuenta y como se relacionan entre ellos. Así mismo, ponen de manifiesto las necesidades organizacionales que deben afrontar aquellas empresas que deseen implantar un verdadero modelo de gestión adoptado a la economía digital, especialmente a los relacionados con la computación en la nube.The digital economy is contributing decisively to boosting the competitiveness of the productive sector of organizations, but this involves migrating from an economy with only a small amount of Information Technology use, to one where it is common, and normal, to use these technologies in all economic, cultural and social activities. This adoption of technology generates increases in productivity and competitivity of enterprises, organizations and administrations, thus contributing to the creation of wealth, and greater opportunities for progress. Contributing to and furthering studies related to these models of adoption and their contribution to improving competitiveness of an organization is the goal of this research project. Today, cloud computing systems or cloud computing are one of the most realistic ways to improve the competitivity, but not only for Information Technology, also as a new economic model of resource use, exploitation of applications and data, or for providing business services. This study seeks to explore and research the evolution of this still new technology, its application in the medium and long term as well as trying to find the formula for the optimal model of technology adoption in an organization. Normally these studies are focused on purely technological aspects without trying to study the impact on the organizations. This research project presents another approach, to optimize and adapt these technologies to the reality of our production sector. The results of this study reflect what critical factors should be considered and how they are interrelated. It also shows the organizational demands that must be considered by those companies wishing to implement a real management model adopted to the digital economy, especially those related to cloud computing.Premio Extraordinario de Doctorado U