Dayu: Fast and Low-interference Data Recovery in Very-large Storage Systems


Zhufan Wang and Guangyan Zhang, Tsinghua University; Yang Wang, The Ohio State University; Qinglin Yang, Tsinghua University; Jiaji Zhu, Alibaba Cloud


This paper investigates I/O and failure traces from a realworld large-scale storage system: it finds that because of the scale of the system and because of the imbalanced and dynamic foreground traffic, no existing recovery protocol can compute a high-quality re-replicating strategy in a short time. To address this problem, this paper proposes Dayu, a timeslot based recovery architecture. For each timeslot, Dayu only schedules a subset of tasks which are expected to be finished in this timeslot: this approach reduces the computation overhead and naturally can cope with the dynamic foreground traffic. In each timeslot, Dayu incorporates a greedy algorithm with convex hull optimization to achieve both high speed and high quality. Our evaluation in a 1,000-node cluster and in a 3,500-node simulation both confirm that Dayu can outperform existing recovery protocols, achieving high speed and high quality.

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@inproceedings {234988,
author = {Zhufan Wang and Guangyan Zhang and Yang Wang and Qinglin Yang and Jiaji Zhu},
title = {Dayu: Fast and Low-interference Data Recovery in Very-large Storage Systems},
booktitle = {2019 USENIX Annual Technical Conference (USENIX ATC 19)},
year = {2019},
isbn = {978-1-939133-03-8},
address = {Renton, WA},
pages = {993--1008},
url = {},
publisher = {USENIX Association},
month = jul,

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