6,505 research outputs found

    MOON: MapReduce On Opportunistic eNvironments

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    Abstract—MapReduce offers a flexible programming model for processing and generating large data sets on dedicated resources, where only a small fraction of such resources are every unavailable at any given time. In contrast, when MapReduce is run on volunteer computing systems, which opportunistically harness idle desktop computers via frameworks like Condor, it results in poor performance due to the volatility of the resources, in particular, the high rate of node unavailability. Specifically, the data and task replication scheme adopted by existing MapReduce implementations is woefully inadequate for resources with high unavailability. To address this, we propose MOON, short for MapReduce On Opportunistic eNvironments. MOON extends Hadoop, an open-source implementation of MapReduce, with adaptive task and data scheduling algorithms in order to offer reliable MapReduce services on a hybrid resource architecture, where volunteer computing systems are supplemented by a small set of dedicated nodes. The adaptive task and data scheduling algorithms in MOON distinguish between (1) different types of MapReduce data and (2) different types of node outages in order to strategically place tasks and data on both volatile and dedicated nodes. Our tests demonstrate that MOON can deliver a 3-fold performance improvement to Hadoop in volatile, volunteer computing environments

    On Energy-efficient Checkpointing in High-throughput Cycle-stealing Distributed Systems

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    Checkpointing is a fault-tolerance mechanism commonly used in High Throughput Computing (HTC) environments to allow the execution of long-running computational tasks on compute resources subject to hardware and software failures and interruptions from resource owners. With increasing scrutiny of the energy consumption of IT infrastructures, it is important to understand the impact of checkpointing on the energy consumption of HTC environments. In this paper we demonstrate through trace-driven simulation on real-world datasets that existing checkpointing strategies are inadequate at maintaining an acceptable level of energy consumption whilst reducing the makespan of tasks. Furthermore, we identify factors important in deciding whether to employ checkpointing within an HTC environment, and propose novel strategies to curtail the energy consumption of checkpointing approaches

    Energy-efficient checkpointing in high-throughput cycle-stealing distributed systems

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    Checkpointing is a fault-tolerance mechanism commonly used in High Throughput Computing (HTC) environments to allow the execution of long-running computational tasks on compute resources subject to hardware or software failures as well as interruptions from resource owners and more important tasks. Until recently many researchers have focused on the performance gains achieved through checkpointing, but now with growing scrutiny of the energy consumption of IT infrastructures it is increasingly important to understand the energy impact of checkpointing within an HTC environment. In this paper we demonstrate through trace-driven simulation of real-world datasets that existing checkpointing strategies are inadequate at maintaining an acceptable level of energy consumption whilst maintaing the performance gains expected with checkpointing. Furthermore, we identify factors important in deciding whether to exploit checkpointing within an HTC environment, and propose novel strategies to curtail the energy consumption of checkpointing approaches whist maintaining the performance benefits

    Data Science and Ebola

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    Data Science---Today, everybody and everything produces data. People produce large amounts of data in social networks and in commercial transactions. Medical, corporate, and government databases continue to grow. Sensors continue to get cheaper and are increasingly connected, creating an Internet of Things, and generating even more data. In every discipline, large, diverse, and rich data sets are emerging, from astrophysics, to the life sciences, to the behavioral sciences, to finance and commerce, to the humanities and to the arts. In every discipline people want to organize, analyze, optimize and understand their data to answer questions and to deepen insights. The science that is transforming this ocean of data into a sea of knowledge is called data science. This lecture will discuss how data science has changed the way in which one of the most visible challenges to public health is handled, the 2014 Ebola outbreak in West Africa.Comment: Inaugural lecture Leiden Universit

    A complete simulator for volunteer computing environments

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    Volunteer computing is a type of distributed computing in which ordinary people donate their idle computer time to science projects like SETI@home, Climateprediction.net and many others. BOINC provides a complete middleware system for volunteer computing, and it became generalized as a platform for distributed applications in areas as diverse as mathematics, medicine, molecular biology, climatology, environmental science, and astrophysics. In this document we present the whole development process of ComBoS, a complete simulator of the BOINC infrastructure. Although there are other BOINC simulators, our intention was to create a complete simulator that, unlike the existing ones, could simulate realistic scenarios taking into account the whole BOINC infrastructure, that other simulators do not consider: projects, servers, network, redundant computing, scheduling, and volunteer nodes. The output of the simulations allows us to analyze a wide range of statistical results, such as the throughput of each project, the number of jobs executed by the clients, the total credit granted and the average occupation of the BOINC servers. This bachelor thesis describes the design of ComBoS and the results of the validation performed. This validation compares the results obtained in ComBoS with the real ones of three different BOINC projects (Einstein@home, SETI@home and LHC@home). Besides, we analyze the performance of the simulator in terms of memory usage and execution time. This document also shows that our simulator can guide the design of BOINC projects, describing some case studies using ComBoS that could help designers verify the feasibility of BOINC projects.Ingeniería Informátic

    Operating policies for energy efficient large scale computing

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    PhD ThesisEnergy costs now dominate IT infrastructure total cost of ownership, with datacentre operators predicted to spend more on energy than hardware infrastructure in the next five years. With Western European datacentre power consumption estimated at 56 TWh/year in 2007 and projected to double by 2020, improvements in energy efficiency of IT operations is imperative. The issue is further compounded by social and political factors and strict environmental legislation governing organisations. One such example of large IT systems includes high-throughput cycle stealing distributed systems such as HTCondor and BOINC, which allow organisations to leverage spare capacity on existing infrastructure to undertake valuable computation. As a consequence of increased scrutiny of the energy impact of these systems, aggressive power management policies are often employed to reduce the energy impact of institutional clusters, but in doing so these policies severely restrict the computational resources available for high-throughput systems. These policies are often configured to quickly transition servers and end-user cluster machines into low power states after only short idle periods, further compounding the issue of reliability. In this thesis, we evaluate operating policies for energy efficiency in large-scale computing environments by means of trace-driven discrete event simulation, leveraging real-world workload traces collected within Newcastle University. The major contributions of this thesis are as follows: i) Evaluation of novel energy efficient management policies for a decentralised peer-to-peer (P2P) BitTorrent environment. ii) Introduce a novel simulation environment for the evaluation of energy efficiency of large scale high-throughput computing systems, and propose a generalisable model of energy consumption in high-throughput computing systems. iii iii) Proposal and evaluation of resource allocation strategies for energy consumption in high-throughput computing systems for a real workload. iv) Proposal and evaluation for a realworkload ofmechanisms to reduce wasted task execution within high-throughput computing systems to reduce energy consumption. v) Evaluation of the impact of fault tolerance mechanisms on energy consumption

    Porting and tuning of the Mont-Blanc benchmarks to the multicore ARM 64bit architecture

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    This project is about porting and tuning the Mont-Blanc benchmarks to the multicore ARM 64 bits architecture. The Mont-Blanc benchmarks are part of the Mont-Blanc European project and they have been developed internally in the BSC (Barcelona Supercomputing Center). The project will explore the possibilities that an ARM architecture can offer running in a HPC (High Performance Computing) setup, this includes to learn how to tune and adapt a parallelized computer program and analyze its execution behavior. As part of the project, we will analyze the performance of each benchmark using instrumentation tools such like Extrae and Paraver. Each benchmark will be adapted, tuned and executed mainly in the three new Mont-Blanc mini-clusters, Thunder (ARMv8 custom), Merlin (ARMv8 custom) and Jetson TX (ARMv8 cortex-a57) using the OmpSs programming model. The evolution of the performance obtained will be shown followed by a brief analysis of the results after each optimization.Aquest projecte es basa en adaptar i afinar els Mont-Blanc benchmarks a l’arquitectura multinucli ARM 64 bits. Els Mont-Blanc benchmarks formen part del projecte Europeu Mont-Blanc i han estat desenvolupats internament en el BSC (Barcelona Supercomputing Center). Aquest projecte explorarà el potencial d’usar l’arquitectura ARM en un entorn HPC (High Performance Computing), això inclou aprendre a adaptar i afinar un programa paral·lel, i analitzar el seu comportament durant l’execució. Com a part del projecte, s’analitzarà el rendiment de cada benchmark usant eines d’instrumentació com Extrae o Paraver. Cada benchmark serà adaptat, afinat i executat en els tres nous miniclústers de Mont-Blanc, Thunder (ARMv8 personalitzat), Merlin (ARMv8 personalitzat) i Jetson TX (ARMv8 cortex-a57) usant el model de programació OmpSs. Es mostrarà l’evolució del rendiment, seguit d’una breu explicació dels resultats després de cada optimització.Este proyecto se basa en adaptar y afinar los Mont-blanc benchmarks a la arquitectura multi-núcleo ARM 64 bits. Los Mont-Blanc benchmarks forman parte del proyecto Europeo Mont-Blanc y han sido desarrollados internamente en el BSC (Barcelona Supercomputing Center). Este proyecto explorará el potencial de usar la arquitectura ARM en un entorno HPC (High Performance Computing), esto incluye aprender a adaptar y afinar un programa paralelo, y analizar su comportamiento durante la ejecución. Como parte del proyecto, se analizará el rendimiento de cada benchmark usando herramientas de instrumentación como Extrae o Paraver. Cada benchmark será adaptado, afinado y ejecutado en los tres nuevos mini-clústeres de Mont-Blanc, Thunder (ARMv8 personalizado), Merlin (ARMv8 personalizado) y Jetson TX (ARMv8 cortex-a57) usando el modelo de programación OmpSs. Se mostrará la evolución del rendimiento obtenido, y una breve explicación de los resultados después de cada optimización
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