ClusterRR: a record and replay framework for virtual machine cluster

ABSTRACTThe Record and Replay (RnR) technology provides the ability to reproduce past execution of systems deterministically. It has many prominent applications, including fault tolerance, security analysis, and failure diagnosis. In system virtualization, previous RnR researches mainly focus on individual VM, including coherent replaying of multi-core systems, reducing performance penalty and storage overhead. However, with the emerging of distributed systems deployed in virtual machine clusters (VMC), the existing RnR technology of individual VM can not meet the requirements of analyzers and developers. The critical challenge for VMC RnR is to maintain the consistency of global state. In this paper, we propose ClusterRR, a RnR framework for VMC. To solve the inconsistency problem, we propose coordination protocols to schedule the record and replay process of VMs. Meanwhile, we employ a Hybrid RnR approach to reduce the performance penalty and storage costs caused by recording network events. Moreover, we implement ClusterRR on QEMU/KVM platform and utilize a network packets retransmission framework to guarantee the reproducibility of VMC replay. Last, we conduct a series of experiments to measure its efficiency and overhead. The results show that ClusterRR would efficiently replay the execution of the whole VMC at instruction-level granularity.