1,841 research outputs found
A Survey of Fault-Tolerance and Fault-Recovery Techniques in Parallel Systems
Supercomputing systems today often come in the form of large numbers of
commodity systems linked together into a computing cluster. These systems, like
any distributed system, can have large numbers of independent hardware
components cooperating or collaborating on a computation. Unfortunately, any of
this vast number of components can fail at any time, resulting in potentially
erroneous output. In order to improve the robustness of supercomputing
applications in the presence of failures, many techniques have been developed
to provide resilience to these kinds of system faults. This survey provides an
overview of these various fault-tolerance techniques.Comment: 11 page
Advanced information processing system: The Army fault tolerant architecture conceptual study. Volume 1: Army fault tolerant architecture overview
Digital computing systems needed for Army programs such as the Computer-Aided Low Altitude Helicopter Flight Program and the Armored Systems Modernization (ASM) vehicles may be characterized by high computational throughput and input/output bandwidth, hard real-time response, high reliability and availability, and maintainability, testability, and producibility requirements. In addition, such a system should be affordable to produce, procure, maintain, and upgrade. To address these needs, the Army Fault Tolerant Architecture (AFTA) is being designed and constructed under a three-year program comprised of a conceptual study, detailed design and fabrication, and demonstration and validation phases. Described here are the results of the conceptual study phase of the AFTA development. Given here is an introduction to the AFTA program, its objectives, and key elements of its technical approach. A format is designed for representing mission requirements in a manner suitable for first order AFTA sizing and analysis, followed by a discussion of the current state of mission requirements acquisition for the targeted Army missions. An overview is given of AFTA's architectural theory of operation
Study of a unified hardware and software fault-tolerant architecture
A unified architectural concept, called the Fault Tolerant Processor Attached Processor (FTP-AP), that can tolerate hardware as well as software faults is proposed for applications requiring ultrareliable computation capability. An emulation of the FTP-AP architecture, consisting of a breadboard Motorola 68010-based quadruply redundant Fault Tolerant Processor, four VAX 750s as attached processors, and four versions of a transport aircraft yaw damper control law, is used as a testbed in the AIRLAB to examine a number of critical issues. Solutions of several basic problems associated with N-Version software are proposed and implemented on the testbed. This includes a confidence voter to resolve coincident errors in N-Version software. A reliability model of N-Version software that is based upon the recent understanding of software failure mechanisms is also developed. The basic FTP-AP architectural concept appears suitable for hosting N-Version application software while at the same time tolerating hardware failures. Architectural enhancements for greater efficiency, software reliability modeling, and N-Version issues that merit further research are identified
The Impact of RDMA on Agreement
Remote Direct Memory Access (RDMA) is becoming widely available in data
centers. This technology allows a process to directly read and write the memory
of a remote host, with a mechanism to control access permissions. In this
paper, we study the fundamental power of these capabilities. We consider the
well-known problem of achieving consensus despite failures, and find that RDMA
can improve the inherent trade-off in distributed computing between failure
resilience and performance. Specifically, we show that RDMA allows algorithms
that simultaneously achieve high resilience and high performance, while
traditional algorithms had to choose one or another. With Byzantine failures,
we give an algorithm that only requires processes (where
is the maximum number of faulty processes) and decides in two (network)
delays in common executions. With crash failures, we give an algorithm that
only requires processes and also decides in two delays. Both
algorithms tolerate a minority of memory failures inherent to RDMA, and they
provide safety in asynchronous systems and liveness with standard additional
assumptions.Comment: Full version of PODC'19 paper, strengthened broadcast algorith
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