O objetivo do trabalho é a implementação de características de adaptabilidade ao VIC, software livre de videoconferência sobre multicast. O VIC é um software para vídeo utilizado pelos principais frameworks de videoconferência em uso no mundo. O trabalho é focado em cima do VIC para o Access Grid, desenvolvido no Argone National Laboratory. Videoconferência é uma aplicação que consome muitos recursos da rede e do processamento da máquina, devido à grande quantidade de informações com que trabalha e à velocidade com que estas informações devem ser processadas e transmitidas. Pelas próprias características intrínsecas de uma transmissão de vídeo, não são admitidos atrasos. O trabalho analisa as principais tecnologias e o estado da arte em videoconferência, tanto na parte de transmissão quanto na parte de codificação e decodificação de sinais. As principais ferramentas em uso são apresentadas com suas características próprias. Os dois principais enfoques de adaptabilidade para transmissão e recepção de vídeo são expostos. O trabalho propõe um modelo misto, baseado nestes dois enfoques. A partir daí é exposto o novo algoritmo criado e os resultados de alguns testes realizados. Até hoje, apenas uma tentativa foi feita de acrescentar características de adaptabilidade à condição da rede ao VIC, porém essa não se encontra em uso. O trabalho propõe um novo algoritmo de adaptabilidade utilizando características das duas principais tendências atualmente em pesquisa. / The goal of the work is to implement adaptability features to VIC, free software to deliver videoconferencing over multicast. VIC is a software to transmit video used by the main videoconferencing frameworks in use worldwide. The focus of the work is on VIC to Access Grid, developed at Argone National Laboratory. Videoconferencing is an application that uses too much resources of the network and processing power of the machine, due to the huge amount of information that it handles and due to the speed needed to process and transmit this information. For its own intrinsic properties, delays are not allowed in videoconferencing. The work analyses the main technologies and the state of the art in videoconferencing, both in transmission and in encoding and decoding of signals. The main tools in use are presented with their own characteristics. The two main approaches of adaptability for video transmission and reception are shown. The work proposes a new model, based on both approaches in a mixed way. The new algorithm created is shown together with the results of some tests made. Until today, only one try was made to add adaptability to the network conditions to VIC, but it is not in use. The work proposes a new adaptability algorithm using features of the two main trends in research today.

The design of a parallel and distributed computing system is a very complicated task. It requires a detailed understanding of the design issues and of the theoretical and practical aspects of their solutions. Firstly, this thesis discusses in detail the major concepts and components required to make parallel and distributed computing a reality. A multithreaded and distributed framework capable of analysing the simulation data produced by a pedestrian simulation software was developed. Secondly, this thesis discusses the origins and fundamentals of Grid computing and the motivations for its use in High Energy Physics. Access to the data produced by the Large Hadron Collider (LHC) has to be provided for more than five thousand scientists all over the world. Users who run analysis jobs on the Grid do not necessarily have expertise in Grid computing. Simple, userfriendly and reliable monitoring of the analysis jobs is one of the key components of the operations of the distributed analysis; reliable monitoring is one of the crucial components of the Worldwide LHC Computing Grid for providing the functionality and performance that is required by the LHC experiments. The CMS Dashboard Task Monitoring and the CMS Dashboard Job Summary monitoring applications were developed to serve the needs of the CMS community.

Workshop Mensch-Computer-Vernetzung Eine Einführung in Geschichte und Ideen des Grid-Computing. Kurze Vorstellung des 'Globus-Toolkit'.

DOGMA is a distributed computing architecture developed at Brigham Young University. It makes use of idle computers to provide additional computing resources to applications, similar to Seti@home. DOGMA's ability to scale to large numbers of computers is hindered by its strict client-server architecture. Recent research with DOGMA has shown that introducing localized peer-to-peer downloading abilities enhances DOGMA's performance while reducing the amount of network and server usage. This thesis proposes to further extend the peer-to-peer abilities of DOGMA to include peering client server communication by creating dynamic clusters of clients. The client clusters aggregate their communication with only one client communicating with the server directly. This further reduces the network traffic and server usage allowing more clients to connect to a single server and increasing the overall scalability of DOGMA systems.

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No description available.

Grid computing is a field of research that combines many computers from distant locations to form one large computing resource. In order to be able to make use of the full potential of such a system there is a need to effectively manage resources on the Grid. There are numerous scheduling systems to perform this management for clusters of computers and a few scheduling systems for the Grid. These systems try for optimality (or close to optimality) with the goals of obtaining good throughput and minimizing job completion time. In this research, we examine issues that we believe have not been tackled in schedulers for the Grid. These issues revolve around the problem of coordinating resources belonging to separate administrative domains and scheduling in this context. In order for grid computing's vision of virtual organizations to be realized to its fullest extent, there is a need to implement and test schedulers that find resources and schedule tasks on them in a manner that is transparent to the user. These resources might be on a different administrative domain altogether and obtaining either resource or user account information on those resources might be difficult. Also, each organization might require their own policies and mechanisms to be enforced. Hence having a centralized scheduler is not feasible due to the pragmatics of the Grid. There are two basic aims to this thesis. The first aim is to design and implement a framework that takes administrative concerns into consideration during scheduling. The aim of the framework is to provide a lightweight, extensible, secure and scalable architecture under which multiple scheduling algorithms can be implemented. Second, we evaluate two prototypical of scheduling algorithms in the context of this framework. Scheduling algorithms are diverse and the applications are varied. Thus no single algorithm can obtain a good mapping for every application. We believe that different scheduling algorithms will be necessary to schedule different types of applications. In order to facilitate development of such algorithms, a framework in which it is easy to integrate other scheduling algorithms is necessary. The framework developed in this project is designed for such extensibility. / Master of Science

A realização de videoconferências sem o uso de equipamentos que possuam tecnologia proprietária ou sem o uso de redes não comerciais (como a Internet 2) ou com características não comuns (como o protocolo Multicast) tem se revelado um desafio para os estudiosos do assunto. Este trabalho apresenta uma proposta de solução desse problema demonstrando que é possível estabelecer-se uma videoconferência entre muitas salas sobre a Internet 1, com qualidade de serviço, usando equipamentos comerciais comuns de informática e sem sobrecarga da rede. Para isso, por intermédio da integração de duas tecnologias grid (AccessGrid e Grid Delivery), são propostas as bases de uma nova versão de Access Grid, chamado MPAG (MultiPeer Access Grid). / The development of videoconferencing without the use of equipments with customized technology or without commercial networks (like Internet 2) or without common characteristics (as Multicast, for instance) has appeared as a challenge to the subject researchers. This work presents a proposal of solution to this problem, showing that is possible to create a videoconference between many rooms under the Internet 1, with quality of service, using common commercial computing equipments and without overloading the network. For this, two technologies of grid (AccessGrid and Grid Delivery) have been integrated, proposing the basis of a new version of Access Grid, called MPAG (MultiPeer Access Grid).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Computer grids emerged in the 90 s with the goal of using geographically dispersed computers for high performance computing. Through grids, computational power of a supercomputer can be reached in a simple, efficient and inexpensive way. Such benefits led to highlights in researchs of computer grids. Recently, appeared on market graphics adapter cards whose computational power overcomes, and by a wide margin, even the most modern processors commonly used. This led to researchs that resulted in programming techniques relatively easy to learn and did simplify application programming for these processors. These techniques effectively introduced the processors in the business of high performance computing. The use of these techniques gave rise to General Purpose computing on Graphic Processing Units (GPGPU). Grids applications are generally programmed through a grid computing framework. TUXUR is one of those frameworks and is under development by Master s Program Graduate at the Federal University of Santa Maria. This dissertation discusses the development of a TUXUR s foreseen feature. Such feature allows the computer grid managed by TUXUR to enjoy the benefits of GPGPU applications, particularly regarding to the best use of the nodes s hardware that comprises it. The immediate impact of this synergy is the significant increase in grid computational capacity without adding new computers. The findings of the evaluation highlights the importance of using GPGPU tasks that take advantage of this programming technique, even when performed in a grid. / Grades de computadores surgiram na década de 90 com o objetivo de utilizar computadores geograficamente dispersos para computação de alto desempenho. Através destas grades, pode-se chegar ao poder computacional de um supercomputador de uma forma simples, eficiente e barata. Tais benefícios fizeram com que pesquisas em grades de computadores obtivessem destaques no ramo da computação. Recentemente, surgiram no mercado placas adaptadoras gráficas cujo poder computacional supera, e com larga vantagem, mesmo os mais modernos processadores de uso geral. Isso deu origem a pesquisas que resultaram em técnicas de programação relativamente fáceis de aprender e que simplificam a programação de aplicações para estes processadores. Estas técnicas efetivamente introduziram estes processadores no ramo de computação de alto desempenho. A utilização destas técnicas deu origem à programação de propósito geral em unidades de processamento gráfico (General-Purpose computation on Graphical Processor Units-GPGPU). Aplicações de grades são geralmente programadas através de um framework de computação em grade. TUXUR é um destes frameworks e encontra-se em desenvolvimento por mestrandos do Programa de Pós-graduação em Informática da Universidade Federal de Santa Maria. Este trabalho aborda o desenvolvimento de uma funcionalidade prevista no TUXUR. Tal funcionalidade permite que a grade de computadores gerenciada por TUXUR usufrua dos benefícios de aplicações GPGPU, sobretudo no que diz respeito à melhor utilização do hardware dos nós que a compõem. O reflexo imediato desta sinergia é o aumento significativo da capacidade computacional da grade sem o acréscimo de novos computadores. Os resultados encontrados na avaliação evidenciam a importância do uso de GPGPU nas tarefas que se beneficiam desta técnica de programação, mesmo quando executadas em uma grade.

A realização de videoconferências sem o uso de equipamentos que possuam tecnologia proprietária ou sem o uso de redes não comerciais (como a Internet 2) ou com características não comuns (como o protocolo Multicast) tem se revelado um desafio para os estudiosos do assunto. Este trabalho apresenta uma proposta de solução desse problema demonstrando que é possível estabelecer-se uma videoconferência entre muitas salas sobre a Internet 1, com qualidade de serviço, usando equipamentos comerciais comuns de informática e sem sobrecarga da rede. Para isso, por intermédio da integração de duas tecnologias grid (AccessGrid e Grid Delivery), são propostas as bases de uma nova versão de Access Grid, chamado MPAG (MultiPeer Access Grid). / The development of videoconferencing without the use of equipments with customized technology or without commercial networks (like Internet 2) or without common characteristics (as Multicast, for instance) has appeared as a challenge to the subject researchers. This work presents a proposal of solution to this problem, showing that is possible to create a videoconference between many rooms under the Internet 1, with quality of service, using common commercial computing equipments and without overloading the network. For this, two technologies of grid (AccessGrid and Grid Delivery) have been integrated, proposing the basis of a new version of Access Grid, called MPAG (MultiPeer Access Grid).