Efficient Search-Based Automatic Execution Replay for Virtual Machines

Execution replay of virtual machines is a useful method for debugging applications in the cloud computing environment. The traditional methods to reproduce a bug is recording every details during the system runtime. However, these methods will incur much overhead and affect the system performance, especially in a multicore processor system. In this paper, we present a virtualization-based execution replay method consisting of three steps. First, we only record some necessary events in the runtime and take a memory checkpoint in a regular interval. Second, we search for execution paths between every two adjacent checkpoints. Third, we reproduce the bugs according to these paths. We can decrease the logging overhead in the runtime by searching instead of logging. We have implemented the method and evaluate it on Xen. The experimental results demonstrate that our method can reduce the runtime overhead by 30% effectively.