752 research outputs found

    A Survey of Fault-Tolerance and Fault-Recovery Techniques in Parallel Systems

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    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

    Sensornet checkpointing: enabling repeatability in testbeds and realism in simulations

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    When developing sensor network applications, the shift from simulation to testbed causes application failures, resulting in additional time-consuming iterations between simulation and testbed. We propose transferring sensor network checkpoints between simulation and testbed to reduce the gap between simulation and testbed. Sensornet checkpointing combines the best of both simulation and testbeds: the nonintrusiveness and repeatability of simulation, and the realism of testbeds

    FADI: a fault-tolerant environment for open distributed computing

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    FADI is a complete programming environment that serves the reliable execution of distributed application programs. FADI encompasses all aspects of modern fault-tolerant distributed computing. The built-in user-transparent error detection mechanism covers processor node crashes and hardware transient failures. The mechanism also integrates user-assisted error checks into the system failure model. The nucleus non-blocking checkpointing mechanism combined with a novel selective message logging technique delivers an efficient, low-overhead backup and recovery mechanism for distributed processes. FADI also provides means for remote automatic process allocation on the distributed system nodes

    An enhanced index-based checkpointing algorithm for distributed systems

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    Rollback-recovery in distributed systems is important for fault-tolerant computing. Without fault tolerance mechanisms, an application running on a system has to be restarted from scratch if a fault happens in the middle of its execution, resulting in loss of useful computation. To provide efficient rollback-recovery for fault-tolerance in distributed systems, it is significant to reduce the number of checkpoints under the existence of consistent global checkpoints in index-based distributed checkpointing algorithms. Because of the dependencies among the processes states that induced by inter-process communication in distributed systems, asynchronous checkpointing may suffer from the domino effect. Therefore, a consistent global checkpoint should always be ensured to restrict the rollback distance. The quasi-synchronous checkpointing protocols achieve synchronization in a loose fashion. Index-based checkpointing algorithm is a kind of typical quasi- synchronous checkpointing mechanism. The algorithm proposed in this thesis follows a new strategy to update the checkpoint interval dynamically as opposed to the static interval used by the existing algorithms explained in the previous chapter. Whenever a process takes a forced checkpoint due to the reception of a message with sequence number higher than the sequence number of the process, the checkpoint interval is either reset or the next basic checkpoint is skipped depending on when the massage has been received. The simulation is built on SPIN, a tool to trace logical design errors and check the logical consistency of protocols and algorithms in distributed systems. Simulation results show that the proposed scheme can reduce the number of induced forced-checkpoints per message 27- 32% on an average as compared to the traditional strategies

    Integrated analysis of error detection and recovery

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    An integrated modeling and analysis of error detection and recovery is presented. When fault latency and/or error latency exist, the system may suffer from multiple faults or error propagations which seriously deteriorate the fault-tolerant capability. Several detection models that enable analysis of the effect of detection mechanisms on the subsequent error handling operations and the overall system reliability were developed. Following detection of the faulty unit and reconfiguration of the system, the contaminated processes or tasks have to be recovered. The strategies of error recovery employed depend on the detection mechanisms and the available redundancy. Several recovery methods including the rollback recovery are considered. The recovery overhead is evaluated as an index of the capabilities of the detection and reconfiguration mechanisms

    Design and analysis of an efficient energy algorithm in wireless social sensor networks

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    Because mobile ad hoc networks have characteristics such as lack of center nodes, multi-hop routing and changeable topology, the existing checkpoint technologies for normal mobile networks cannot be applied well to mobile ad hoc networks. Considering the multi-frequency hierarchy structure of ad hoc networks, this paper proposes a hybrid checkpointing strategy which combines the techniques of synchronous checkpointing with asynchronous checkpointing, namely the checkpoints of mobile terminals in the same cluster remain synchronous, and the checkpoints in different clusters remain asynchronous. This strategy could not only avoid cascading rollback among the processes in the same cluster, but also avoid too many message transmissions among the processes in different clusters. What is more, it can reduce the communication delay. In order to assure the consistency of the global states, this paper discusses the correctness criteria of hybrid checkpointing, which includes the criteria of checkpoint taking, rollback recovery and indelibility. Based on the designed Intra-Cluster Checkpoint Dependence Graph and Inter-Cluster Checkpoint Dependence Graph, the elimination rules for different kinds of checkpoints are discussed, and the algorithms for the same cluster checkpoints, different cluster checkpoints, and rollback recovery are also given. Experimental results demonstrate the proposed hybrid checkpointing strategy is a preferable trade-off method, which not only synthetically takes all kinds of resource constraints of Ad hoc networks into account, but also outperforms the existing schemes in terms of the dependence to cluster heads, the recovery time compared to the pure synchronous, and the pure asynchronous checkpoint advantage. © 2017 by the authors. Licensee MDPI, Basel, Switzerland

    A parallel algorithm for switch-level timing simulation on a hypercube multiprocessor

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    The parallel approach to speeding up simulation is studied, specifically the simulation of digital LSI MOS circuitry on the Intel iPSC/2 hypercube. The simulation algorithm is based on RSIM, an event driven switch-level simulator that incorporates a linear transistor model for simulating digital MOS circuits. Parallel processing techniques based on the concepts of Virtual Time and rollback are utilized so that portions of the circuit may be simulated on separate processors, in parallel for as large an increase in speed as possible. A partitioning algorithm is also developed in order to subdivide the circuit for parallel processing
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