An Efficient Time-Based Checkpointing Protocol for Mobile Computing Systems over Mobile IP

Time-based coordinated checkpointing protocols are well suited for mobile computing systems because no explicit coordination message is needed while the advantages of coordinated checkpointing are kept. However, without coordination, every process has to take a checkpoint during a checkpointing process. In this paper, an efficient time-based coordinated checkpointing protocol for mobile computing systems over Mobile IP is proposed. The protocol reduces the number of checkpoints per checkpointing process to nearly minimum, so that fewer checkpoints need to be transmitted through the costly wireless link. Our protocol also performs very well in the aspects of minimizing the number and size of messages transmitted in the wireless network. In addition, the protocol is nonblocking because inconsistencies can be avoided by the piggybacked information in every message. Therefore, the protocol brings very little overhead to a mobile host with limited resource. Additionally, by taking advantage of reliable timers in mobile support stations, the time-based checkpointing protocol can adapt to wide area networks.     

A Low Overhead Logging Scheme for Fast Recovery in Distributed Shared Memory Systems

This paper presents an efficient, writer-based logging scheme for recoverable distributed shared memory systems, in which logging of a data item is performed by its writer process, instead of every process that accesses the item logging it. Since the writer process maintains the log of data items, volatile storage can be used for logging. Only the readers' access information needs to be logged into the stable storage of the writer process to tolerate multiple failures. Moreover, to reduce the frequency of stable logging, only the data items accessed by multiple processes are logged with their access information when the items are invalidated, and also semantic-based optimization in logging is considered. Compared with the earlier schemes in which stable logging was performed whenever a new data item was accessed or written by a process, the size of the log and the logging frequency can be significantly reduced in the proposed scheme.     

基于Lustre文件系统的MPI检查点系统实现技术与性能测试

基于协同式检查点的回卷恢复是在大规模并行计算机系统中得到采用的一项重要容错技术,其性能开销主要为协同协议和检查点映像存储所决定.描述了一个在MPICH2中实现的应用透明的并行检查点系统,相比已有的技术,该系统有以下特点：1）协同协议操作利用了并行应用的近邻通信特性,通过虚连接方法减少协议的处理开销;2）采用Lustre文件系统简化检查点映像文件管理的复杂性;3）通过并行I/O操作提高性能,优化检查点映像的存储过程.实际应用的测试表明,该检查点系统具有较小的运行时间开销和良好的可扩展性.     

Supporting Cost-Effective Fault Tolerance in Distributed Message-Passing Applications with File Operations

In this paper we present an approach to reliable distributed computing, which incorporates fault tolerance into applications at low cost, in terms of both run-time performance and programming effort required to construct reliable application software. In our model fault tolerance is based on distributed consistent checkpointing and rollback-recovery integrated with a user-level reliable transmission protocol. By employing novel techniques 8and algorithms, our approach is distinguished from other consistent checkpointing schemes by the following features: first, minimum communication overhead for constructing a consistent distributed checkpoint and catching messages in transit during checkpointing; second, tolerance to message losses due to site failures or unreliable non-FIFO networks; and third, efficient checkpointing and recovery of persistent state, i.e., user files. Based on the model, a software library prototype called Libra has been implemented for supporting fault tolerance in distributed message-passing applications with file operations. The library provides an easy to use programming interface including message-passing and file I/O primitives, which hides the complexity of both fault-tolerant network communications and checkpointing and recovering user files from the application level. Experience with a number of long-running distributed applications shows that Libra can provide fault tolerance in a cost-effective manner.     

双机容错系统FTDC的设计与实现

给出了一种利用现有计算机和少量必要的硬件,以容错管理软件为主要手段实现的低成本双机容错系统,主要介绍了该机的容错设计、容错管理软件的实现以及关键技术等问题。     

一种基于移动计算的非阻塞协同检查点算法

传统分布式网络中协同检查点算法有许多优点,但移动计算环境有很多新问题,如缺少可靠存储、低无线网络带宽、高移动性、断开连接和能量限制等,使得协同检查点算法不能很好地适用于移动计算环境.为此提出一种适合移动计算环境的非阻塞的协同检查点算法,算法中检查点的发起和同步由移动支持站完成,只需记录部分中途消息就能实现一致可恢复.算...     

机群系统中检查点卷回恢复协议分析

检查点机制作为一种软件容错机制,可以很好地满足机群系统的容错要求,本文详细分析了各类检查点卷回恢复协议,并比较它们的性能和特点。