对等网络中基于失效规律的自适应失效检测器

Adaptive Failure Detector Based on Failure Distribution in P2P Networks

如何在保障准确性的前提下以较低的负载快速发现失效节点是失效检测器的设计目标,为此提出一种GA-FD的改进算法F-AFD.首先分析了P2P系统中节点的失效规律,基于对节点在线概率的预测实现对检测周期的动态调整,有效地降低了检测速度对检测周期的限制;在此基础上,为了以更低的检测负载同时满足多种应用定量描述的准确性及检测速度需求,提出了F-AFD.最后通过实验对F-AFD的正确性及检测性能进行了验证和分析,并证明了在部分同步模型下F-AFD可实现一个◇P类的失效检测器,具备解决一致性等分布式基础问题所需要的完整性和准确性.

How to quickly find node failures with lower loads on the assumption of guaranteeing the accuracy is the design goal of the failure detector. In this paper, an improved algorithm of the GA-FD detector named F-AFD is proposed. Firstly, the nodes＇ failure distribution in the P2P system is analyzed. Based on the prediction of the nodes＇ online probability, the dynamic adjustment to the detection period is realized, which has reduced the detection time＇s restriction to the detection period. Secondly, an F-AFD detector is proposed, which can provide QoS of failure detection for multiapplications according to quantitative QoS metrics with lower detection loads. Finally, the experimental results validate the correctness and performance of F-AFD. In addition, it proves F-AFD implements a failure detector that belongs to ◇P in the partially synchronous model, which meets the ability to solve fundamental issues such as consensus, atomic broadcast, etc.