计算机科学 ›› 2026, Vol. 53 ›› Issue (6): 367-375.doi: 10.11896/jsjkx.260200107
孙婧, 王弈, 陈海燕
SUN Jing, WANG Yi, CHEN Haiyan
摘要： 在现代多可用区(Multi-AZ)云存储系统中,故障呈现出显著的层次化与相关性特征。传统的纠删码(如RS码)或扁平化喷泉码方案往往忽略了物理拓扑结构,导致在处理频发的局部故障时产生高昂的跨AZ修复带宽,且难以兼顾异构网络下的灵活性。针对这一问题,提出了一种面向多可用区环境的分层AZ-Fountain编码模型。该模型将喷泉码的无码率特性与多AZ故障域结构进行显式耦合,设计了双层编码架构:在AZ内部采用局部优化双模态度分布(AZ-OBMD),以实现零跨区流量的局部修复;在全局采用Raptor-link度分布(AZ-RLD),以保障AZ级灾难下的高效恢复。实验结果表明,与RS码、LRC及最新的AZ-Code相比,所提方法在局部单块故障下能够与LRC一样保持零跨AZ流量,且其参与解码的数据块数量与修复延迟更低;在AZ级灾难恢复中显著降低了修复延迟与传输开销,实现了可靠性与修复代价的系统性权衡。
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