基于消息延迟预测的自适应失效检测模型

Adaptive failure detection model based on message delay prediction

失效检测是实现高可用性的一个关键技术,通常采用超时机制判断进程是否失效的方法实现。然而,由于网络状况的不断变化,缺乏自适应机制的失效检测器难以满足应用对QoS的需求。自适应失效检测要求失效检测器能够根据实际应用和网络负载变化而动态地改变检测的质量。在对现有自适应失效检测算法研究、分析的基础上提出一种基于消息延迟预测的失效检测模型,采用基于历史消息延迟预测下一个消息延迟的方法,实现了一种PA-AFD自适应失效检测算法。实验及分析表明该算法在保证检测准确性和完整性的同时缓解了网络延迟对失效检测的影响。

Failure detection is a key technology to realize high availability.It usually uses overtime mechanism to determine whether a process fails or not.But old failure detectors without adaptive mechanism can not meet the requirements of Quality of Service （QoS） of applications all the time because of the instability of the network.Adaptive failure detection requires that failure detectors can dynamically adjust the detection quality according to the variations of applications and the load of the network.A new failure detection model based on the predicted message delay was proposed on the basis of researching and analyzing the existing adaptive failure detection algorithms.An adaptive failure detection algorithm named P_A-AFD based on the prediction from historical message delay was realized.The experimental results and analysis show that the algorithm can relieve the affect of message delay on the failure detection while ensuring the accuracy and integrity of detection.