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Bibliographic Details
Main Authors: Kang, Xueze, Xiang, Guangyu, Wang, Yuxin, Zhang, Hao, Fang, Yuchu, Zhou, Yuhang, Tang, Zhenheng, Lv, Youhui, Maman, Eliran, Wasserman, Mark, Zameret, Alon, Bian, Zhipeng, Chen, Shushu, Yu, Zhiyou, Wang, Jin, Wu, Xiaoyu, Zheng, Yang, Tian, Chen, Chu, Xiaowen
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.00606
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Table of Contents:
  • Large-scale LLM pretraining now runs across $10^5$--$10^6$ accelerators, making failures routine and elasticity mandatory. We posit that an elastic-native training system must jointly deliver (i) parameter consistency, (ii) low mean time to recovery (MTTR), (iii) high post-change throughput, and (iv) computation consistency. No prior system achieves all four simultaneously. To achieve these goals, we present ElasWave, which delivers per-step fault tolerance via multi-dimensional scheduling across graph, dataflow, DVFS, and RNG. ElasWave reshapes and reshards micro-batches while preserving the global batch size and gradient scale. It performs online pipeline resharding with asynchronous parameter migration and interleaves ZeRO partitions, reducing parameter recovery processes to disjoint rank-to-rank transfers. It further leverages DVFS to absorb pipeline bubbles and reshards RNG to keep computation consistency. Together, a dynamic communicator enables in-place communication group edits, while per-step in-memory snapshots support online verification and redistribution. We evaluate ElasWave on 96 NPUs and benchmark it against state-of-the-art baselines: throughput improves by $1.35\times$ over ReCycle and $1.60\times$ over TorchFT; communicator recovery completes within one second (up to $82\times/3.6\times$ faster than full/partial rebuilds); migration MTTR drops by as much as $51\%$; and convergence deviation is reduced by approximately $78\%$.