Who's Afraid of Uncorrectable Bit Errors? Online Recovery of Flash Errors with Distributed Redundancy
Who's Afraid of Uncorrectable Bit Errors? Online Recovery of Flash Errors with Distributed Redundancy
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发表时间：
2019
影响因子：
27.8
通讯作者：
Amy Tai;Andrew Kryczka;Shobhit O. Kanaujia;K. Jamieson;M. Freedman;Asaf Cidon
中科院分区：
文献类型：
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作者：
Amy Tai;Andrew Kryczka;Shobhit O. Kanaujia;K. Jamieson;M. Freedman;Asaf Cidon
由于其高性能和每位成本降低，闪存存储是数据中心的主要存储介质，但是，闪光灯耐力是一个永久的问题，并且由于技术趋势，随后的一代闪光设备逐渐越来越短。在本文中经历了不正确的位错误Direct是一组利用分布式级别的技术，可以通过使用端到端的方法来提高分布式存储系统的可靠性，从而使新一代的较密集和较低的闪存存储技术直接在两个现实世界中的存储系统上实施：ZippydB，这是Facebook生产中的一家分布式钥匙值商店，它得到了支持并支持Rocksdb的交易，并且HDF，在Facebook上进行的分布式文件系统，将ZippyDB中的应用程序可见率降低了100次以上，并且恢复时间超过10,000。没有经验应用程序可见错误的位错误率。错误，直接有助于延长闪存寿命。
Due to its high performance and decreasing cost per bit, flash storage is the main storage medium in datacenters for hot data. However, flash endurance is a perpetual problem, and due to technology trends, subsequent generations of flash devices exhibit progressively shorter lifetimes before they experience uncorrectable bit errors. In this paper, we present an approach for addressing the flash lifetime problem by allowing devices to operate at much higher bit error rates. We present DIRECT, a set of techniques that harnesses distributed-level redundancy to enable the adoption of new generations of denser and less reliable flash storage technologies. DIRECT does so by using an end-to-end approach to increase the reliability of distributed storage systems. We implemented DIRECT on two real-world storage systems: ZippyDB, a distributed key-value store in production at Facebook that is backed by and supports transactions on top of RocksDB, and HDFS, a distributed file system. When tested on production traces at Facebook, DIRECT reduces application-visible error rates in ZippyDB by more than 100⇥ and recovery time by more than 10,000⇥. DIRECT also allows HDFS to tolerate a 10,000–100,000⇥ higher bit error rate without experiencing application-visible errors. By significantly increasing the availability of distributed storage systems in the face of bit errors, DIRECT helps extend flash lifetimes.