Network-aware heuristics for inter-domain meta-scheduling in Grids

AbstractGrid computing generally involves the aggregation of geographically distributed resources in the context of a particular application. As such resources can exist within different administrative domains, requirements on the communication network must also be taken into account when performing meta-scheduling, migration or monitoring of jobs. Similarly, coordinating efficient interaction between different domains should also be considered when performing such meta-scheduling of jobs. A strategy to perform peer-to-peer-inspired meta-scheduling in Grids is presented. This strategy has three main goals: (1) it takes the network characteristics into account when performing meta-scheduling; (2) communication and query referral between domains is considered, so that efficient meta-scheduling can be performed; and (3) the strategy demonstrates scalability, making it suitable for many scientific applications that require resources on a large scale. Simulation results are presented that demonstrate the usefulness of this approach, and it is compared with other proposals from literature

VGrid: una infraestructura grid virtual con fines educacionales

La computación Grid es una tecnología enfocada a compartir recursos heterogéneos a gran escala. Sin embargo, su alto coste de implantación, así como la elevada experiencia necesaria para su mantenimiento, la hacen inviable en el contexto educacional. Multitud de universidades disponen de esta tecnología o acceso a un Grid externo, orientado fundamentalmente a la investigación y/o computación intensiva. Por lo tanto no está disponible para satisfacer objetivos educacionales, limitando el conocimiento de esta tecnología a los estudiantes únicamente como concepto teórico y a lo sumo a la prueba de algunos comandos de ejecución y monitorización de trabajos simples. Como posible solución didáctica se propone la virtualización como medio para crear un pequeño Grid funcional que puede ser utilizado en un computador individual, evitando los requisitos económicos y de gestión necesarios en un Grid real. El objetivo fundamental de esta plataforma es mostrar la tecnología Grid a los estudiantes, desde un punto de vista práctico y permitirles interaccionar con un Grid de apariencia real, dotándoles de los conocimientos y experiencia básica requerida para trabajar en entornos laborales basados en la tecnología Grid.SUMMARY -- Grids are highly distributed and heterogeneous systems based on the resource sharing world-wide. As a result, their implantation costs are high as well as the experience needed to their maintenance. Those facts makes them unfeasible in educational contexts. Many Universities have their own Grid or access to an external one to make research and intensive computation. However, they are not usually available for educational objectives. Consequently, student knowledge of this technology is limited to theoretical concepts or, in the best scenario, to some executions and monitoring commands to see its functionality. This article proposes the use of virtualization as a possible solution to create a functional Grid, which can be used on a single computer, avoiding the economic and management requirements of a real Grid. The main objective of this framework is to introduce students to Grid technology from a practical point of view, letting them interact with a real-appearance Grid, giving them the education and basic experience required to work in real Grid environments.Peer Reviewe

QoS Provisioning by Meta-Scheduling in Advance within SLA-Based Grid Environments

The establishment of agreements between users and the entities which manage the Grid resources is still a challenging task. On the one hand, an entity in charge of dealing with the communication with the users is needed, with the aim of signing resource usage contracts and also implementing some renegotiation techniques, among others. On the other hand, some mechanisms should be implemented which decide if the QoS requested could be achieved and, in such case, ensuring that the QoS agreement is provided. One way of increasing the probability of achieving the agreed QoS is by performing meta-scheduling of jobs in advance, that is, jobs are scheduled some time before they are actually executed. In this way, it becomes more likely that the appropriate resources are available to run the jobs when needed. So, this paper presents a framework built on top of Globus and the GridWay meta-scheduler to provide QoS by means of performing meta-scheduling in advance. Thanks to this, QoS requirements of jobs are met (i.e. jobs are finished within a deadline). Apart from that, the mechanisms needed to manage the communication between the users and the system are presented and implemented through SLA contracts based on the WS-Agreement specification

Diseño de un encaminador orientado a tráfico multimedia en entornos LAN

El objetivo básico de la tesis consiste en el desarrollo de una nueva arquitectura de encaminador, orientada al soporte eficiente de tráfico multimedia en entornos lan. El encaminador es capaz de satisfacer las necesidades de calidad de servicio (qos) de los flujos de datos generados por aplicaciones multimedia, así como de proporcionar alta productividad y baja latencia media al tráfico convencional de tio best-effort, usual en este tipo de entornos. Las aportaciones de la tesis han consistido, además de la propuesta general de la arquitectura del encaminador multimedia mmr, en una serie de algoritmos de planificación del tráfico. Estos algoritmos resultan imprescindibles para un adecuado reparto del ancho de banda de los enlaces y del crossbar, que tenga en cuenta las diferentes necesidades impuestas por las distintas aplicaciones. Finalmente, se ha comprobado mediante simulación la validez tanto de la arquitectura propuesta, como de los algoritmos de planificación del trafico desarrollados, para cumplir con los objetivos marcados

VGrid: Una Infraestructura Grid Virtual con fines Educacionales

La computación Grid es una tecnología enfocada a compartir recursos heterogéneos a gran escala. Sin embargo, su alto coste de implantación, así como la elevada experiencia necesaria para su mantenimiento, la hacen inviable en el contexto educacional. Multitud de universidades disponen de esta tecnología o acceso a un Grid externo, orientado fundamentalmente a la investigación y/o computación intensiva. Por lo tanto no está disponible para satisfacer objetivos educacionales, limitando el conocimiento de esta tecnología a los estudiantes únicamente como concepto teórico y a lo sumo a la prueba de algunos comandos de ejecución y monitorización de trabajos simples. Como posible solución didáctica se propone la virtualización como medio para crear un pequeño Grid funcional que puede ser utilizado en un computador individual, evitando los requisitos económicos y de gestión necesarios en un Grid real. El objetivo fundamental de esta plataforma es mostrar la tecnología Grid a los estudiantes, desde un punto de vista práctico y permitirles interaccionar con un Grid de apariencia real, dotándoles de los conocimientos y experiencia básica requerida para trabajar en entornos laborales basados en la tecnología Grid.Grids are highly distributed and heterogeneous systems based on the resource sharing world-wide. As a result, their implantation costs are high as well as the experience needed to their maintenance. Those facts makes them unfeasible in educational contexts. Many Universities have their own Grid or access to an external one to make research and intensive computation. However, they are not usually available for educational objectives. Consequently, student knowledge of this technology is limited to theoretical concepts or, in the best scenario, to some executions and monitoring commands to see its functionality. This article proposes the use of virtualization as a possible solution to create a functional Grid, which can be used on a single computer, avoiding the economic and management requirements of a real Grid. The main objective of this framework is to introduce students to Grid technology from a practical point of view, letting them interact with a real-appearance Grid, giving them the education and basic experience required to work in real Grid environments.Este trabajo ha sido apoyado conjuntamente por el MEC y MICINN Español y la Comisión Europea (fondos FEDER) a través de los proyectos “Consolider Ingenio-2010 CSD2006-00046”, “TIN2009-14475-C04” y a través de una beca FPI asociada al proyecto “TIN2009-14475-C04-03”, y también por la JCCM a través del proyecto “PII1C09-0101-9476”

Aplicaciones de blockchain en IoT y computación en la niebla

Desde su concepción en el 2008, la tecnología blockchain ha causado un gran interés en los últimos años. La aplicación inicial fue en el ámbito de las criptomonedas, dando soporte a Bitcoin. Este hecho ya de por sí supuso una revolución en el ámbito de la economía, pues la tecnología hacía posible prescindir de intermediarios (es decir, bancos y entidades financieras) en las transacciones económicas, ahorrando costes y evitando un control centralizado de la información registrada en la blockchain. Más adelante, la tecnología ha evolucionadopara incluir sobre ella la posibilidad de registrar lógica de negocio (es decir, código informático) en la propia blockchain a través de los contratos inteligentes. Esto, junto con el desarrollo de plataformas que permiten implementar blockchains con acceso controlado, ha abierto la puerta a un sinfín de aplicaciones más allá de las criptomonedas. Por otro lado, el concepto de internet de las cosas (IoT, en inglés), donde objetos cotidianos se conectan a internet, generando cantidades ingentes de datos que procesar (usualmente en lo que se conoce como computación en la niebla), es un campo de investigación e innovación que también ha generado gran interés de la industria y la academia en los últimos años. Las tecnologías IoT suponen un complemento perfecto para dotar de conexión con el mundo real a la información almacenada en la blockchain. En este trabajo realizaremos una breve introducción a blockchain y al internet de las cosas y revisaremos algunas aplicaciones que combinan ambas temáticas. Finalizaremos con una pequeña introducción a la línea de investigación sobre blockchain en entornos IoT que llevamos a cabo en el Instituto de Investigación en Informática de Albacete (I3A) de la Universidad de Castilla-La Mancha

Exploring the use of blockchain in resource-constrained fog computing environments

Fog computing has become a complementary technology to cloud computing and addresses some of the cloud computing threats such as the response time and network bandwidth demand. Fog computing successes processing data and storing data near to the edge, and usually is combined with container virtualization to provide hardware isolation. Empowered by these capabilities, numerous Internet of Things (IoT) applications are developed as virtualized instances on resource-constrained fog nodes such as single-board computers (SBC). In addition, blockchain has emerged as a key technology that is transforming the way we share information. Blockchain technology represents a decentralised, distributed, and immutable database ledger and is a potential solution for the distributed ecosystem of IoT applications. The distributed structure of blockchain is naturally suitable for IoT applications. However, it introduces new challenges related to CPU overhead or response time. This paper proposes a layered architecture that integrates blockchain technology and OS-level virtualization technology to develop fog-based IoT applications. It also provides insights for future deployments through a proof-of-concept use case harnessing SBCs, in this case Raspberry Pi, as blockchain-enabled fog nodes to drive virtualized IoT applications. The study shows that the maximum CPU overhead added by a permissioned blockchain based on Ethereum on the Raspberry Pi is around a 25% under stress situations while the overhead introduced by the sealer process is negligible. These results support the feasibility of using blockchain on resource-constrained fog nodes for supporting IoT applications

Voice quality after endoscopic laser surgery and radiotherapy for early glottic cancer: objective measurements emphasizing the Voice Handicap Index

We analyzed the functional outcome and self-evaluation of the voice of patients with T1 glottic carcinoma treated with endoscopic laser surgery and radiotherapy. We performed an objective voice evaluation, as well as a physical, emotional and functional well being assessment of 19 patients treated with laser surgery and 18 patients treated with radiotherapy. Voice quality is affected both by surgery and radiotherapy. Voice parameters only show differences in the maximum phonation time between both treatments. Results in the Voice Handicap Index show that radiotherapy has less effect on patient voice quality perception. There is a reduced impact on the patient’s perception of voice quality after radiotherapy, despite there being no significant differences in vocal quality between radiotherapy and laser cordectomy

Debate effectiveness for the strengthening the university educational work from the curricular work

Foundation: The well-conceived debate can strengthen the university educative influence from the curricular work, but the strategies designed for citizen training in the universities privilege the professional to the detriment of training them to social reality questioning. Objective: To demonstrate the effectiveness of the debate for the strengthening of university educative influence from the curricular work. Methods: Pedagogical research carried out at the University of Medical Sciences of Cienfuegos, from September 2016 to January 2017, with the Philosophy class in the first year of the Dentistry Major. The debate deliberated by the teacher was introduced on the basis of articles with impact on the current Cuban society, previously selected and student oriented. It was considered as a requirement that the student had possibilities of a previous preparation before the debate. Two measurements were taken, one in November and another at the end of the semester. A survey was applied that measured: students 'satisfaction with the method used, students' perception about the contribution to the formation of values. Results: All the students are satisfied by the method used; At the end of the semester 77, 8 % of the students considered that the method contributes to the formation of values and reinforcement of patriotic feelings in them. Conclusion: Offering students the possibility of confronting different opinions is possible if a relaxed and rewarding climate is achieved. It is corroborated that the work of the teacher is irreplaceable at university formation from the curricular work of each discipline