Scalable multithreading in a low latency myrinet cluster

In this paper we present some implementation details of a programming model – pCoR – that combines primitives to launch remote processes and threads with communication over Myrinet.B asically, we present the efforts we have made to achieve high performance communication among threads of parallel/distributed applications. The expected advantages of multiple threads launched across a low latency cluster of SMP workstations are emphasized with a graphical application that manages huge maps consisting of several JPEG images

MPICH-G2: A Grid-Enabled Implementation of the Message Passing Interface

Application development for distributed computing "Grids" can benefit from tools that variously hide or enable application-level management of critical aspects of the heterogeneous environment. As part of an investigation of these issues, we have developed MPICH-G2, a Grid-enabled implementation of the Message Passing Interface (MPI) that allows a user to run MPI programs across multiple computers, at the same or different sites, using the same commands that would be used on a parallel computer. This library extends the Argonne MPICH implementation of MPI to use services provided by the Globus Toolkit for authentication, authorization, resource allocation, executable staging, and I/O, as well as for process creation, monitoring, and control. Various performance-critical operations, including startup and collective operations, are configured to exploit network topology information. The library also exploits MPI constructs for performance management; for example, the MPI communicator construct is used for application-level discovery of, and adaptation to, both network topology and network quality-of-service mechanisms. We describe the MPICH-G2 design and implementation, present performance results, and review application experiences, including record-setting distributed simulations.Comment: 20 pages, 8 figure

Accurate acoustic ranging system using android smartphones

ACCURATE ACOUSTIC RANGING SYSTEM USING ANDROID SMARTPHONES By Mohammadbagher Fotouhi, Master of Science A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University Virginia Commonwealth University 2017 Major Director: Dr. Ruixin Niu, Associate Professor of Department of Electrical and Computer Engineering In this thesis, we present the design, implementation, and evaluation of an android ranging system, a high-accuracy acoustic-based ranging system which allows two android mobile phones to learn their physical distance from each other. In this system we propose a practical solution for accurate ranging based on acoustic communication between speakers and microphones on two smartphones. Using the audible-band acoustic signal with the Wi-Fi assistance without the sound disturbance is promising for large deployment. Our method is a pure software-based solution and uses only the most basic set of commodity hardware: a speaker, a microphone, and Wi-Fi communication. So it is readily applicable to many commercial-off-the-shelf mobile devices like cell phones. Our system is the result of several design goals, including user privacy, decentralized administration, and low cost. Rather than relying on any centralized management which tracks the user’s location to help them find their distance, our system helps devices learn their distance from each other without advertising their location information with any centralized management. Compared to alternatives that require special-purpose hardware or pre-existence of precision location infrastructure , our system is applicable on most of off-the-shelf components so it is a commodity-based solution will obviously have wider applications and is cost effective. Currently, two smartphones are used to estimate the distance between them through Wi-Fi and audio communications. The basic idea is estimating the distance between two phones by estimating the traveling time of audio signal from one phone to the other as the speed of sound is known. The preliminary results of ranging demonstrate that our algorithm could achieve high accuracy, and stable and reliable results for real time smartphone-based indoor ranging

DECK: A new model for a distributed executive kernel integrating communication and multithreading for support of distributed object oriented application with fault tolerance support

DECK (Distributed Executive Communication Kernel) is a communication layer that provides support for multithreading and fault tolerance support. The approach retained in DECK is close to other distributed communication kernels like PM2, Athapascan, Nexus, TPVM or Chant in its way to integrate communication and multithreading to efficiently overlap communication by computation and provide low latency remote thread creation mechanisms. However, DECK differs from these communication kernels from the services offered and its modular architecture. The main goal of DECK is to implement a new model for the design of distributed executive kernel to efficiently use the new underlying hardware architectures (SMP architectures and fast communication adapters like Myrinet or memory oriented adapter like SCI) and provide a portable layer that abstract the problems linked with the integration of communication and multithreading while offering support for heterogeneity. A great lack in the current implementation of communication libraries or distributed executive kernel is the support for basic services at the thread level and support for fault tolerance support. Indeed, communication library like PVM or MPI are often used as communication layer to ensure portability and take benefits of specific implementation to ensure a good efficiency on specific architectures however the support for fault tolerance support, multithreading, scalability and interoperability are usually not offered. In the case of DECK, we propose a model where a distributed application can dynamically instantiate clusters of processes among an heterogeneous network of computers or parallel machines and this using multiple communication protocols or communication interfaces to ensure good performances regarding the underlying hardware architecture. The programming model proposed offer both classic synchronous and asynchronous remote service calls for thread creation and message passing for synchronization and data exchange. These basic functionalities, that form the low level communication and execution layer of DECK, are enforced by a service layer that propose the basic fault tolerant services like naming and group services or data management services for the marshaling and un-marshalling of complex data structures. The layered and modular approach followed by DECK enable many other extensions while keeping a high degree of portability and efficiency.Sistemas Distribuidos - Redes ConcurrenciaRed de Universidades con Carreras en Informática (RedUNCI

Technologies for Ubiquitous Supercomputing: A Java Interface to the Nexus Communication system

We use the term ubiquitous supercomputing to refer to systems that integrate low- and mid-range computing systems, advanced networks and remote high-end computers with the goal of enhancing the computational power accessible from local environments. Such systems promise to enable new applications in areas as diverse as smart instruments and collaborative environments. However, they also demand tools for transporting code between computers and for establishing flexible, dynamic communication structures. In this article, we propose that these requirements be satisfied by introducing Java classes that implement the global pointer and remote service request mechanisms defined by a communication library called Nexus. Java supports transportable code; Nexus provides communication support and represents the core communication framework for Globus, a project building infrastructure for ubiquitous supercomputing. We explain how this NexusJava library is implemented and illustrate its use with examples

Uintah: a massively parallel problem solving environment

Journal ArticleThis paper describes Uintah, a component-based visual problem solving environment (PSE) that is designed to specifically address the unique problems of massively parallel computation on terascale computing platforms. Uintah supports the entire life cycle of scientific applications by allowing scientific programmers to quickly and easily develop new techniques, debug new implementations, and apply known algorithms to solve novel problems. Uintah is built on three principles: 1) As much as possible, the complexities of parallel execution should be handled for the scientist, 2) software should be reusable at the component level, and 3) scientists should be able to dynamically steer and visualize their simulation results as the simulation executes. To provide this functionality, Uintah builds upon the best features of the SCIRun PSE and the DOE Common Component Architecture (CCA)