Hydra : Resilient and Highly Available Remote Memory


Youngmoon Lee, Hanyang University; Hasan Al Maruf and Mosharaf Chowdhury, University of Michigan; Asaf Cidon, Columbia University; Kang G. Shin, The University of Michigan


We present Hydra, a low-latency, low-overhead, and highly available resilience mechanism for remote memory. Hydra can access erasure-coded remote memory within a single-digit μs read/write latency, significantly improving the performance-efficiency tradeoff over the state-of-the-art – it performs similar to in-memory replication with 1.6× lower memory overhead. We also propose CodingSets, a novel coding group placement algorithm for erasure-coded data, that provides load balancing while reducing the probability of data loss under correlated failures by an order of magnitude. With Hydra, even when only 50% memory is local, unmodified memory-intensive applications achieve performance close to that of the fully in-memory case in the presence of remote failures and outperforms the state-of-the-art remote-memory solutions by up to 4.35×.

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@inproceedings {277814,
title = {Hydra : Resilient and Highly Available Remote Memory},
booktitle = {20th USENIX Conference on File and Storage Technologies (FAST 22)},
year = {2022},
isbn = {978-1-939133-26-7},
address = {Santa Clara, CA},
pages = {181--198},
url = {https://www.usenix.org/conference/fast22/presentation/lee},
publisher = {USENIX Association},
month = feb,

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