From Detection to Recovery: Operational Analysis on LLM Pre-training with 504 GPUs

Fuente: arXiv
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Autores principales: Kang, Daemyung, Hwang, Eunjin, Lee, Hanjeong, Kim, HyeokJin, Koo, Hyunhoi, Shin, Jeongkyu, Kang, Jeongseok, Kang, Jihyun, Kim, Joongi, Lee, Junbum, Yang, Jungseung, Cho, Kyujin, Song, Youngsook
Formato: Preprint
Publicado: 2026
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author Kang, Daemyung
Hwang, Eunjin
Lee, Hanjeong
Kim, HyeokJin
Koo, Hyunhoi
Shin, Jeongkyu
Kang, Jeongseok
Kang, Jihyun
Kim, Joongi
Lee, Junbum
Yang, Jungseung
Cho, Kyujin
Song, Youngsook
author_facet Kang, Daemyung
Hwang, Eunjin
Lee, Hanjeong
Kim, HyeokJin
Koo, Hyunhoi
Shin, Jeongkyu
Kang, Jeongseok
Kang, Jihyun
Kim, Joongi
Lee, Junbum
Yang, Jungseung
Cho, Kyujin
Song, Youngsook
contents Large-scale AI training is now fundamentally a distributed systems problem, and hardware failures have become routine operating conditions rather than rare exceptions. Public operational evidence from production training clusters, however, remains scarce. This technical report presents an empirical analysis of a 63-node NVIDIA B200 production cluster (504 GPUs), using 55 days of Prometheus time-series data and 73 days of operational logs covering 224 multi-node training sessions. The cluster operates within a cross-organizational environment in which five parties (SKT, Upstage, Lablup, NVIDIA Korea, and VAST Data) share a unified monitoring pipeline. This arrangement enabled joint diagnosis of a 60-node-scale storage I/O bottleneck that did not appear at 2-4-node scale, a production-scale phenomenon no single team could isolate alone. Drawing on a months-long pre-training campaign, we perform three quantitative analyses yielding four findings. First, statistical analysis over 751 Prometheus metrics and 10 XID-identified GPU failures achieves a 10/10 detection rate (2/10 pre-XID) at ~0.84 false positives per day. No single metric is consistently dominant across failure types, motivating a multi-signal detection strategy. Second, profiling 523 checkpoint events along the GPU VRAM to NFS path attributes the "bandwidth paradox" (1.4-10.4% utilization of 200 Gbps RoCE) to saturation of the 128-slot NFS RPC layer. Third, multi-node failure response shows concentrated exclusions (top 3 of 63 nodes account for >50% of all exclusions) and an auto-retry chain success rate of 33.3% over 12 chains (73 attempts), 2.7x the 12.5% manual recovery rate; the median retry interval is 11 min (IQR 10-11). All analyses are grounded in production infrastructure providing session-level workload management, GPU-centric scheduling, and unified observability.
format Preprint
id arxiv_https___arxiv_org_abs_2605_09370
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle From Detection to Recovery: Operational Analysis on LLM Pre-training with 504 GPUs
Kang, Daemyung
Hwang, Eunjin
Lee, Hanjeong
Kim, HyeokJin
Koo, Hyunhoi
Shin, Jeongkyu
Kang, Jeongseok
Kang, Jihyun
Kim, Joongi
Lee, Junbum
Yang, Jungseung
Cho, Kyujin
Song, Youngsook
Distributed, Parallel, and Cluster Computing
Artificial Intelligence
C.4; D.4.5; I.2.11
Large-scale AI training is now fundamentally a distributed systems problem, and hardware failures have become routine operating conditions rather than rare exceptions. Public operational evidence from production training clusters, however, remains scarce. This technical report presents an empirical analysis of a 63-node NVIDIA B200 production cluster (504 GPUs), using 55 days of Prometheus time-series data and 73 days of operational logs covering 224 multi-node training sessions. The cluster operates within a cross-organizational environment in which five parties (SKT, Upstage, Lablup, NVIDIA Korea, and VAST Data) share a unified monitoring pipeline. This arrangement enabled joint diagnosis of a 60-node-scale storage I/O bottleneck that did not appear at 2-4-node scale, a production-scale phenomenon no single team could isolate alone. Drawing on a months-long pre-training campaign, we perform three quantitative analyses yielding four findings. First, statistical analysis over 751 Prometheus metrics and 10 XID-identified GPU failures achieves a 10/10 detection rate (2/10 pre-XID) at ~0.84 false positives per day. No single metric is consistently dominant across failure types, motivating a multi-signal detection strategy. Second, profiling 523 checkpoint events along the GPU VRAM to NFS path attributes the "bandwidth paradox" (1.4-10.4% utilization of 200 Gbps RoCE) to saturation of the 128-slot NFS RPC layer. Third, multi-node failure response shows concentrated exclusions (top 3 of 63 nodes account for >50% of all exclusions) and an auto-retry chain success rate of 33.3% over 12 chains (73 attempts), 2.7x the 12.5% manual recovery rate; the median retry interval is 11 min (IQR 10-11). All analyses are grounded in production infrastructure providing session-level workload management, GPU-centric scheduling, and unified observability.
title From Detection to Recovery: Operational Analysis on LLM Pre-training with 504 GPUs
topic Distributed, Parallel, and Cluster Computing
Artificial Intelligence
C.4; D.4.5; I.2.11
url https://arxiv.org/abs/2605.09370