Hybrid Log-based Fault Tolerant Scheme for Mobile Computing System

Many new characteristics are introduced in the mobile computing system, such as mobility, disconnections, finite power source, vulnerable to physical damage, lack of stable storage. Many log-based rollback recovery fault tolerant schemes were proposed according to the characteristics. However, these schemes may still lead to dramatic loss of computing performance in failure-free or inconsistent recovery after the process fault. In this paper, a hybrid log-based fault tolerant scheme is proposed combining the checkpointing mechanism with the message logging mechanism. The checkpoint, the logs and the happened-before relations are logged synchronously into the memory at local mobile hosts temporarily, and asynchronously into the persistent disk storage in the form of the antecedence graph at local mobile support station. The proposal supports the independent and propagated consistent recovery. By contrast, the results show that the proposal incurs a lower failure-free overhead on the premise of the consistent recoverability.