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Extreme scale HPC (high performance computing) applications require massively many nodes. At these scales, transient hardware and software failures, as well as network congestion and disconnections increase linearly with the number of components. This volatility contributed to the dramatic decrease in applications' MTBF (mean time between failures). Traditional point-to-point transmission APIs semantics are ill-fitted to support applications of extreme scale. In this thesis, we investigate an application dependent network design that focuses on the sustainability of extreme scale high performance computing applications using packet-switching-inspired statistical multiplexing of semantic data tuples and decoupled computations. We report the design and implementation of a distributed tuple space using Cassandra and Zookeeper for tunable spatial and temporal redundancies without negative impact on application performance. We detail the various failure scenarios that can be handled seamlessly by our system and provide a description of the advantages of Stateless Parallel Processing for HPC applications. We report our results on performance, reliability and overall application sustainability. In the preliminary tests, for the most common HPC application categories, the prototype has demonstrated sustained performance, while providing a reliable computing architecture that can withstand multiple failure types without manual checkpoint-restart(CPR). The feasibility of efficient non-stop HPC enables aution-based cloud for more cost efficient HPC applications. For all HPC application categories, we first report a novel method for determining bid-aware checkpointing intervals using fluctuating cloud providers' pricing histories. Subsequently, we explore the effects of bidding in the case of virtual HPC clusters composed of EC2 Spot Instances. We expose the counter-intuitive effects of uniform versus non-uniform bidding, especially in terms of failure rate and failure model, and we propose a method to deal with the problem of predicting the runtime of parallel applications under various bidding strategies. We then show that CPR-free HPC applications require a new optimization strategy. As extreme scale HPC and auction-based cloud computing offer the ultimate computational scale and resource efficiency, they challenge the very foundations in computer science research and development. This thesis answers some critical questions about these challenges and we hope to pave the way for future improvements of the HPC field under increasingly harsh and volatile conditions. / Computer and Information Science

This thesis focuses on the practical use of very large scale relational databases. It leverages two recent breakthroughs in parallel and distributed computing: a) synchronous transaction replication technologies by Justin Y. Shi and Suntain Song; and b) Stateless Parallel Processing principle pioneered by Justin Y. Shi. These breakthroughs enable scalable performance and reliability of database service using multiple redundant shared-nothing database servers. This thesis presents a Functional Horizontal Partitioning method with customizable degree of redundancy to address practical very large scale database applications problems. The prototype VLDB implementation is designed for transparent non-intrusive deployments. The prototype system supports Microsoft SQL Servers databases. Computational experiments are conducted using industry-standard benchmark (TPC-E). / Computer and Information Science

no / Peer-to-Peer (P2P) has become a popular live streaming delivery technology owing to its scalability and low cost. P2P streaming systems often employ multi-channels to deliver streaming to users simultaneously, which leads to a great challenge of allocating server resources among these channels appropriately. Most existing P2P systems resort to over-allocating server resources to different channels, which results in low-efficiency and high-cost. To allocate server resources to different channels efficiently, we propose a dynamic resource allocation algorithm based on a streaming quality model for P2P live streaming systems. This algorithm can improve the channel streaming quality for multi-channel P2P live streaming system and also guarantees the streaming quality of the channels under extreme Internet conditions. In an experiment, the proposed algorithm is validated by the trace data.

IP telephony is defined as the transport of telephony calls over an IP network. IP telephony exploits the integration of voice and data networks. However, enterprises are still reluctant to deploy IP telephony despite the potential increase in productivity and reduction of costs. The principal concerns are: can IP telephony provide the same level of performance in terms of security, reliability, and scalability as traditional telephony? If so, are its proclaimed benefits such as flexibility and mobility cost-effective? The aim of this thesis is to analyze how to deploy IP telephony in large corporations - while providing the necessary security and facilitating mobility. Through the different parts of this thesis, we will analyze the applicable technologies, along with their integration and management. We will focus on the essential requirements for an enterprise of scalability, reliability, flexibility, high-availability, and cost-effectiveness. The massive changes brought about due to the deregulation of telecommunications in nearly all countries, the increasingly global nature of business, and the progressively affordable and power technology underlying information and communication technologies have lead to increasing adoption of IP telephony by residential and commercial users. This thesis will examine these technologies in the context of a very large distributed corporation. / IP telefoni är definierat som transporten av telefon samtal genom ett IP nätverk. IP telefoni utnyttjar integrationen av tal och data nätverk. Dock är affärsföretag fortfarande motsträviga till att införa IP telefoni trots potentiell ökning i produktivitet och minskade kostnader. Huvud bekymren är: kan IP telefoni tillhandahålla samma nivå av prestanda med avseende på säkerhet, tillförlitlighet, och skalbarhet som traditionell telefoni? Och i så fall, är dom proklamerade fördelarna flexibilitet och rörlighet kostnadseffektiva? Målet för detta examensarbete är att analysera hur IP telefoni kan införas i stora affärsföretag - medan samtidigt tillhandahålla nödvändig säkerhet och främja rörlighet. Genom olika delar av detta examensarbete, analyserar vi tillämpliga teknologier, inklusive deras integrering och skötsel. Vi kommer att fokusera på de grundläggande kraven för ett affärsföretag gällande skalbarhet, tillförlitlighet, flexibilitet, hög tillgänglighet, och kostnadseffektivitet. Dom massiva förändringarna frambringade i och med avregleringen av telekommunikation i stort sett alla länder, affärsverksamhetens alltmer globala natur, och de progressivt kostnadseffektiva och kraftfulla underliggande teknologier bakom informations och kommunikations system har lett till ökande adoptering av IP telefoni av både privata och kommersiella användare. Detta examensarbete undersöker relevanta teknologier i samband med mycket stora utbredda affärsföretag. / <p>Exchange student from Centro Politecnico Superior (University of Zaragoza, Spain).</p>