一种面向移动计算的低代价透明检查点恢复协议

移动计算系统中的检查点恢复协议面临着许多与传统分布式系统所不同的问题.在目前已出现的支持移动计算的检查点恢复机制中,基于建立全局一致的检查点的方法不能确保错误的独立恢复;基于m-MSS-m通信的消息日志方法其移动站之间交换的消息需通过移动基站的转发.提出了一种基于消息日志的支持移动站之间直接通信(m-m)的容错协议并给出了相应的算法及正确性证明.与m-MSS-m通信相比,m-m通信有利于降低信道冲突;减少消息传递延迟.仿真结果表明,所设计的协议比传统协议具有更小的无错误状态下引入负载和错误恢复时间.

A Transparent Low-Cost Recovery Protocol for Mobile-to-Mobile Communication

Mobile computing brings new challenges and requirements for checkpointing and recovery protocol. Existing checkpointing-only schemes can not guarantee the independent recovery through creating global consistent checkpoints. Message logging schemes based on mobile-MSS-mobile communication that exchanges messages among mobile hosts may incur large contention on the wireless network and high latency for message transmission relative to the direct mobile host to mobile host (m-m) communication. This paper presents a novel recovery protocol for m-m communication, in which two key problems, message order and duplicate message, are effectively solved. A proof of the protocol correctness is also given. Finally, simulation results indicate that the performance of the proposed approach is better than that of the traditional approaches in terms of fail-free and recovery overhead.