分布式块存储系统中高效纠删码重构技术研究

Study on Efficient Reconstruction of Erasure Code in Distributed Block Storage Systems

当前的海量存储压力导致三副本存储效率越来越难以满足需求。纠删码可以提供和三副本存储相同的可靠性,使用更少的存储容量和网络带宽。提出一种针对分布式块存储访问特点的纠删码故障处理方案——一种纠删码和热备副本相结合的方法,解决临时故障导致的退化读和退化更新问题,同时精细地控制永久故障延迟重构的时间点,减轻重构操作造成的对网络带宽的压力。实验结果表明,相对于传统纠删码,该方案可节省3倍带宽流量,存储成本只有三副本的50%。

Nowadays, the storage efficiency of three-replica mechanism is hard to accept under the pressure of massive stor- age. Meanwhile, erasure code can have the same reliability, and use less storage and bandwidth. Hence, based on study of erasure code in distributed block storage, a fault-tolerance approach specific to block storage access characteristics is proposed. This method includes two sides：a hybrid method of erasure code and hot spare replication, it can solve the de- graded read/write problem due to transient failures;a fine-grained control over the time-point of lazy reconstruction of per- manent failures to decrease the bandwidth pressure, The simulation experiment shows that contrast with traditional era- sure code methods, this approach save 4x bandwidth and its storage cost is only half of three-replica methods.