TSUE: A Two-Stage Data Update Method for an Erasure Coded Cluster File System

Compared to replication-based storage systems, erasure-coded storage incurs significantly higher overhead during data updates. To address this issue, various parity logging methods have been proposed. Nevertheless, due to the long update path and substantial amount of random I/O involved in erasure code update processes, the resulting long latency and low throughput often fail to meet the requirements of high performance applications. To this end, we propose a two-stage data update method called TSUE. TSUE divides the update process into a synchronous stage that records updates in a data log, and an asynchronous stage that recycles the log in real-time. TSUE effectively reduces update latency by transforming random I/O into sequential I/O, and it significantly reduces recycle overhead by utilizing a three-layer log and the spatio-temporal locality of access patterns. In SSDs cluster, TSUE significantly improves update performance, achieving improvements of 7.6× under Ali-Cloud trace, 5× under Ten-Cloud trace, while it also extends the SSD's lifespan by up to 13× through reducing the frequencies of reads/writes and of erase operations.