Latency and Overhead in Transparent Distributed Rollback- Recovery

本研究探讨了无故障开销之间的权衡 以及透明分布式回滚恢复中的输出等待时间。 这 出现折衷，因为使用回滚恢复， “外面的世界”必须推迟，直到足够的恢复信息， 记录在稳定的存储器上，以保证如果发生故障， 系统将永远不会回滚到之前的状态， 执行输出。 由此产生的延迟可以通过以下方式减少： 使稳定存储上的恢复信息保持最新 在无故障运行期间，但以额外故障为代价- 免费管理费。 这项工作包括调查如何回滚恢复方法 基于日志记录的可扩展性，以支持不确定性过程 执行，例如，作为多线程的结果。 不确定性事件记录在稳定存储器上， 在故障恢复期间重放相同的事件。 例如通过 记录同步原语的执行， 信号量，可以支持多线程，其中所有对 共享数据由这些同步原语保护。 检查点为记录 非确定性事件是不可能的或者代价太高。

This research investigates the tradeoff between failure-free overhead and output latency in transparent distributed rollback-recovery. This tradeoff arises because, with rollback-recovery, output to the "outside world" must be delayed until enough recovery information is recorded on stable storage to guarantee that if a failure occurs, the system will never roll back to a state preceding the one from which the output was performed. The resulting latency can be reduced by keeping recovery information on stable storage closely up-to-date during failure-free operation, but at the expense of extra failure- free overhead. The work includes an investigation of how rollback-recovery methods based on logging can be extended to support nondeterministic process execution, occurring, for instance, as a result of multithreading. Nondeterministic events are recorded on stable storage, and are used during failure recovery to replay the same events. For example, by recording the execution of synchronization primitives such as semaphores, one can support multithreading in which all access to shared data is protected by these synchronization primitives. Checkpoints offer an alternative for processes for which recording nondeterministic events is impossible or is too expensive.