167 research outputs found

    Algorithmic Based Fault Tolerance Applied to High Performance Computing

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    We present a new approach to fault tolerance for High Performance Computing system. Our approach is based on a careful adaptation of the Algorithmic Based Fault Tolerance technique (Huang and Abraham, 1984) to the need of parallel distributed computation. We obtain a strongly scalable mechanism for fault tolerance. We can also detect and correct errors (bit-flip) on the fly of a computation. To assess the viability of our approach, we have developed a fault tolerant matrix-matrix multiplication subroutine and we propose some models to predict its running time. Our parallel fault-tolerant matrix-matrix multiplication scores 1.4 TFLOPS on 484 processors (cluster jacquard.nersc.gov) and returns a correct result while one process failure has happened. This represents 65% of the machine peak efficiency and less than 12% overhead with respect to the fastest failure-free implementation. We predict (and have observed) that, as we increase the processor count, the overhead of the fault tolerance drops significantly

    Impact of Event Logger on Causal Message Logging Protocols for Fault Tolerant {MPI}

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    International audienceFault tolerance in MPI becomes a main issue in the HPC community. Several approaches are envisioned from user or programmer controlled fault tolerance to fully automatic fault detection and handling. For this last approach, several protocols have been proposed in the literature. In a recent paper, we have demonstrated that uncoordinated checkpointing tolerates higher fault frequency than coordinated checkpointing. Moreover causal message logging protocols have been proved the most efficient message logging technique. These protocols consist in piggybacking non deterministic events to computation message. Several protocols have been proposed in the literature. Their merits are usually evaluated from four metrics: a) piggybacking computation cost, b) piggyback size, c) applications performance and d) fault recovery performance. In this paper, we investigate the benefit of using a stable storage for logging message events in causal message logging protocols. To evaluate the advantage of this technique we implemented three protocols: 1) a classical causal message protocol proposed in Manetho, 2) a state of the art protocol known as LogOn, 3) a light computation cost protocol called Vcausal. We demonstrate a major impact of this stable storage for the three protocols, on the four criteria for micro benchmarks as well as for the NAS benchmark

    RADIC II : a fault tolerant architecture with flexible dynamic redundancy

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    The demand for computational power has been leading the improvement of the High Performance Computing (HPC) area, generally represented by the use of distributed systems like clusters of computers running parallel applications. In this area, fault tolerance plays an important role in order to provide high availability isolating the application from the faults effects. Performance and availability form an undissociable binomial for some kind of applications. Therefore, the fault tolerant solutions must take into consideration these two constraints when it has been designed. In this dissertation, we present a few side-effects that some fault tolerant solutions may presents when recovering a failed process. These effects may causes degradation of the system, affecting mainly the overall performance and availability. We introduce RADIC-II, a fault tolerant architecture for message passing based on RADIC (Redundant Array of Distributed Independent Fault Tolerance Controllers) architecture. RADIC-II keeps as maximum as possible the RADIC features of transparency, decentralization, flexibility and scalability, incorporating a flexible dynamic redundancy feature, allowing to mitigate or to avoid some recovery side-effects.La demanda de computadores más veloces ha provocado el incremento del área de computación de altas prestaciones, generalmente representado por el uso de sistemas distribuidos como los clusters de computadores ejecutando aplicaciones paralelas. En esta área, la tolerancia a fallos juega un papel muy importante a la hora de proveer alta disponibilidad, aislando los efectos causados por los fallos. Prestaciones y disponibilidad componen un binomio indisociable para algunos tipos de aplicaciones. Por eso, las soluciones de tolerancia a fallos deben tener en consideración estas dos restricciones desde el momento de su diseño. En esta disertación, presentamos algunos efectos colaterales que se puede presentar en ciertas soluciones tolerantes a fallos cuando recuperan un proceso fallado. Estos efectos pueden causar una degradación del sistema, afectando las prestaciones y disponibilidad finales. Presentamos RADIC-II, una arquitectura tolerante a fallos para paso de mensajes basada en la arquitectura RADIC (Redundant Array of Distributed Independent Fault Tolerance Controllers). RADIC-II mantiene al máximo posible las características de transparencia, descentralización, flexibilidad y escalabilidad existentes en RADIC, e incorpora una flexible funcionalidad de redundancia dinámica, que permite mitigar o evitar algunos efectos colaterales en la recuperación

    Checkpointing of parallel applications in a Grid environment

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    The Grid environment is generic, heterogeneous, and dynamic with lots of unreliable resources making it very exposed to failures. The environment is unreliable because it is geographically dispersed involving multiple autonomous administrative domains and it is composed of a large number of components. Examples of failures in the Grid environment can be: application crash, Grid node crash, network failures, and Grid system component failures. These types of failures can affect the execution of parallel/distributed application in the Grid environment and so, protections against these faults are crucial. Therefore, it is essential to develop efficient fault tolerant mechanisms to allow users to successfully execute Grid applications. One of the research challenges in Grid computing is to be able to develop a fault tolerant solution that will ensure Grid applications are executed reliably with minimum overhead incurred. While checkpointing is the most common method to achieve fault tolerance, there is still a lot of work to be done to improve the efficiency of the mechanism. This thesis provides an in-depth description of a novel solution for checkpointing parallel applications executed on a Grid. The checkpointing mechanism implemented allows to checkpoint an application at regions where there is no interprocess communication involved and therefore reducing the checkpointing overhead and checkpoint size

    Hybrid Message Logging. Combining advantages of Sender-based and Receiver-based Approaches

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    AbstractWith the growing scale of High Performance Computing applications comes an increase in the number of interruptions as a consequence of hardware failures. As the tendency is to scale parallel executions to hundred of thousands of processes, fault tolerance is becoming an important matter. Uncoordinated fault tolerance protocols, such as message logging, seem to be the best option since coordinated protocols might compromise applications scalability. Considering that most of the overhead during failure-free executions is caused by message logging approaches, in this paper we propose a Hybrid Message Logging protocol. It focuses on combining the fast recovery feature of pessimistic receiver-based message logging with the low protection overhead introduced by pessimistic sender-based message logging. The Hybrid Message Logging aims to reduce the overhead introduced by pessimistic receiver-based approaches by allowing applications to continue normally before a received message is properly saved. In order to guarantee that no message is lost, a pessimistic sender-based logging is used to temporarily save messages while the receiver fully saves its received messages. Experiments have shown that we can achieve up to 43% overhead reduction compared to a pessimistic receiver- based logging approach

    Process migration for MPI applications based on coordinated checkpoint

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    2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    Local Rollback for Resilient Mpi Applications With Application-Level Checkpointing and Message Logging

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    [Abstract] The resilience approach generally used in high-performance computing (HPC) relies on coordinated checkpoint/restart, a global rollback of all the processes that are running the application. However, in many instances, the failure has a more localized scope and its impact is usually restricted to a subset of the resources being used. Thus, a global rollback would result in unnecessary overhead and energy consumption, since all processes, including those unaffected by the failure, discard their state and roll back to the last checkpoint to repeat computations that were already done. The User Level Failure Mitigation (ULFM) interface – the last proposal for the inclusion of resilience features in the Message Passing Interface (MPI) standard – enables the deployment of more flexible recovery strategies, including localized recovery. This work proposes a local rollback approach that can be generally applied to Single Program, Multiple Data (SPMD) applications by combining ULFM, the ComPiler for Portable Checkpointing (CPPC) tool, and the Open MPI VProtocol system-level message logging component. Only failed processes are recovered from the last checkpoint, while consistency before further progress in the execution is achieved through a two-level message logging process. To further optimize this approach point-to-point communications are logged by the Open MPI VProtocol component, while collective communications are optimally logged at the application level—thereby decoupling the logging protocol from the particular collective implementation. This spatially coordinated protocol applied by CPPC reduces the log size, the log memory requirements and overall the resilience impact on the applications.This research was supported by the Ministry of Economy and Competitiveness of Spain and FEDER funds of the EU (Projects TIN2016-75845-P and the predoctoral grants of Nuria Losada ref. BES-2014-068066 and ref. EEBB-I-17-12005); by EU under the COST Program Action IC1305 Network for Sustainable Ultrascale Computing (NESUS) and a HiPEAC Collaboration Grant and by the Galician Government (Xunta de Galicia) under the Consolidation Program of Competitive Research (ref. ED431C 2017/04). We gratefully thank Galicia Supercomputing Center for providing access to the FinisTerrae-II supercomputer. This material is also based upon work supported by the US National Science Foundation, Office of Advanced Cyberinfrastructure , under Grants No. #1664142 and #1339763Xunta de Galicia; ED431C 2017/04US National Science Foundation, Office of Advanced Cyberinfrastructure; 1664142US National Science Foundation, Office of Advanced Cyberinfrastructure; 133976
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