332,707 research outputs found

    ISIS and META projects

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    The ISIS project has developed a new methodology, virtual synchony, for writing robust distributed software. High performance multicast, large scale applications, and wide area networks are the focus of interest. Several interesting applications that exploit the strengths of ISIS, including an NFS-compatible replicated file system, are being developed. The META project is distributed control in a soft real-time environment incorporating feedback. This domain encompasses examples as diverse as monitoring inventory and consumption on a factory floor, and performing load-balancing on a distributed computing system. One of the first uses of META is for distributed application management: the tasks of configuring a distributed program, dynamically adapting to failures, and monitoring its performance. Recent progress and current plans are reported

    A Problem Solving Environment for Network Computing

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    The current advances in high-speed networks and WWW technologies have made network computing a cost-effective high performance computing environment. New software development models and problem solving environments must be developed to utilize the network computing environment efficiently. In this paper we present Virtual Distributed Computing Environment (VDCE), which provides a problem solving environment for high-performance distributed computing over wide-area networks. VDCE enables scientists to develop distributed applications without knowing the detailed architecture of the underlying resources. VDCE provides well-defined library functions that relieve end users from tedious task implementations and it supports software reusability. The VDCE software architecture consists of two modules: Application Editor, and VDCE Runtime System. Application Editor is a Web-based graphical user interface that helps user to develop network applications and specifies the computing and communication properties of each task within the applications. The VDCE Runtime System schedules the individual tasks of the application to the best available resources, runs, and manages the application execution on the assigned resources. We also present how VDCE can be used as a problem solving environment and how the users can experiment and evaluate the performance of their applications for different VDCE hardware and/or software configurations

    Efficient I/O for Computational Grid Applications

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    High-performance computing increasingly occurs on computational grids composed of heterogeneous and geographically distributed systems of computers, networks, and storage devices that collectively act as a single virtual computer. A key challenge in this environment is to provide efficient access to data distributed across remote data servers. This dissertation explores some of the issues associated with I/O for wide-area distributed computing and describes an I/O system, called Armada, with the following features: a framework to allow application and dataset providers to flexibly compose graphs of processing modules that describe the distribution, application interfaces, and processing required of the dataset before or after computation; an algorithm to restructure application graphs to increase parallelism and to improve network performance in a wide-area network; and a hierarchical graph-partitioning scheme that deploys components of the application graph in a way that is both beneficial to the application and sensitive to the administrative policies of the different administrative domains. Experiments show that applications using Armada perform well in both low- and high-bandwidth environments, and that our approach does an exceptional job of hiding the network latency inherent in grid computing

    Optimizing Network Performance of Computing Pipelines in Distributed Environments

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    Supporting high performance computing pipelines over wide-area networks is critical to enabling large-scale distributed scientific applications that require fast responses for interactive operations or smooth flows for data streaming. We construct analytical cost models for computing modules, network nodes, and communication links to estimate the computing times on nodes and the data transport times over connections. Based on these time estimates, we present the Efficient Linear Pipeline Configuration method based on dynamic programming that partitions the pipeline modules into groups and strategically maps them onto a set of selected computing nodes in a network to achieve minimum end-to-end delay or maximum frame rate. We implemented this method and evaluated its effectiveness with experiments on a large set of simulated application pipelines and computing networks. The experimental results show that the proposed method outperforms the Streamline and Greedy algorithms. These results, together with polynomial computational complexity, make our method a potential scalable solution for large practical deployments

    Diseño de una aplicación paralela de segmentación de imágenes basada en Corba

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    In computer vision, segmentation refers to the process of partitioning a digital image into multiple segments. This process involves a high consumption of resources, both memory and CPU. Therefore, these applications are specially suited for HPC (High-performance computing) environments. Nowadays, a wide variety of methods and algorithms have been available recently to deal with the trouble of the segmentation of images, one of them is used in this project that was called PSRG. This algorithm was designed to be executed parallel. Parallel executions use MPI for performing the data distribution. We have considered interesting to enable these simulations on machines with different architectures and distributed over wide area networks, allowing them to run on heterogeneous architectures and/or operative systems. To achieve it, we started this project with an implementation of a CORBA−based communications library. Once the development finished, we proceed to evaluate the performance of this new version of PSRG.Ingeniería en Informátic

    Ceph as WAN Filesystem – Performance and Feasibility Study through Simulation

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    Recent development in object based distributed file systems (DFS) such as Ceph, GlusterFS as well as the more established ones like Lustre, GPFS, etc. have presented new opportunities to setup next generation of storage infrastructure for cloud computing, big data, and Internet of Things (IoT). However, existing DFSs are typically deployed to Local Area Network (LAN) and generally used for high-performance computing. Extending these DFSs into geographically distributed sites such as Campus Area Network (CAN) and Wide Area Network (WAN) for enterprise applications presents completely different set of challenges and issues. Unlike most implementations that choose a traditional multi sites deployment, i.e., each site implements a virtual storage (via LAN) and links through RESTful APIs (via WAN), we attempt to create a single virtual storage over WAN using Ceph. In this paper, we demonstrate that a properly designed and configured virtualized environment is a valuable tool for researchers to simulate a distributed files system over WAN without an actual physical environment.  By following a few guidelines, the read and write performance results in a simulated environment can indicate the trending of the read and write performance in the actual physical environment.  This implies that the storage design can be verified prior to actual deployment and establish a performance baseline. An obvious benefit is the initial investment of a storage solution is lower. Furthermore, this paper discuss about the challenges of setting up such environment, the feasibility of using Ceph as a single virtual store, and some possible future works

    From Facility to Application Sensor Data: Modular, Continuous and Holistic Monitoring with DCDB

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    Today's HPC installations are highly-complex systems, and their complexity will only increase as we move to exascale and beyond. At each layer, from facilities to systems, from runtimes to applications, a wide range of tuning decisions must be made in order to achieve efficient operation. This, however, requires systematic and continuous monitoring of system and user data. While many insular solutions exist, a system for holistic and facility-wide monitoring is still lacking in the current HPC ecosystem. In this paper we introduce DCDB, a comprehensive monitoring system capable of integrating data from all system levels. It is designed as a modular and highly-scalable framework based on a plugin infrastructure. All monitored data is aggregated at a distributed noSQL data store for analysis and cross-system correlation. We demonstrate the performance and scalability of DCDB, and describe two use cases in the area of energy management and characterization.Comment: Accepted at the The International Conference for High Performance Computing, Networking, Storage, and Analysis (SC) 201

    An environment for workflow applications on wide-area distributed systems

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    ©2001 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Workflow techniques are emerging as an important approach for the specification and management of complex processing tasks. This approach is especially powerful for utilising distributed data and processing resources in widely-distributed heterogeneous systems. We describe our DISCWorld distributed workflow environment for composing complex processing chains, which are specified as a directed acyclic graph of operators. Users of our system can formulate processing chains using either graphical or scripting tools. We have deployed our system for image processing applications and decision support systems. We describe the technologies we have developed to enable the execution of these processing chains across wide-area computing systems. In particular, we present our Distributed Job Placement Language (based on XML) and various Java interface approaches we have developed for implementing the workflow metaphor. We outline a number of key issues for implementing a high-performance, reliable, distributed workflow management system.James, H.A.; Hawick, K.A.; Coddington, P.D
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