一种基于iSCSI的自适应故障检测器的研究

Research of an Adaptive Failure Detector on iSCSI

故障检测器是构建可靠的iSCSI存储系统所必需的基础组件。本文实现了一种iSCSI系统中自适应故障检测器iAFD(adaptive failure detector for iSCSI)。根据心跳(heartbeat)策略,设计了一种自适应心跳机制。故障检测器通过估计预期到达时间来提供一个探测时间,并动态地估算心跳消息超时时限,以适应系统状态的变化,减少故障检测服务的错误。实验表明,该方法与其它的故障检测方法相比,故障检测出错次数较少,检测时间较短,并能够适应高可靠计算系统状况的变化,在侦测的实时性和正确性上提供较好的平衡。

Failure detector is one of the fundamental building blocks to build dependable communication applications over iSCSI systems subject to faults. In this paper, we propose a new implementation of an adaptive failure detectoriAFD （adaptive failure detector for iSCSI）. This implementation is a variant of the heartbeat failure detector which is adaptable. It dynamically estimates the heartbeat detection timeout and transmission delay of the system. It adapts to the change of the system state so as to reduce false detections. The experimental results show that the failure detector has less false detections and shorter detection time compared with normal failure detector. It can adapt the change of the state of high reliable computing system, and achieve a compromise between a good detection time and the need of avoiding false detections.