Run Telemetry, Gradient Spikes, & Crash Recovery Engines
Pre-training across 20,000+ GPUs running continuously for 3 months suffers from inevitable hardware node crashes, cosmic ray bit flips, stragglers, and sudden loss spikes.
Monitoring Critical Telemetry Signals
Real-time dashboards track: 1. Loss curve & gradient norm ||g||. 2. Model FLOPs Utilization (MFU %). 3. Token throughput (tokens/sec/GPU). 4. HBM temperature & ECC memory errors.
Loss Spike Rewind Strategy
When loss spikes to infinity or NaN due to bad data shards or numerical explosion, automated recovery engines rewind to a checkpoint 2,000 steps prior, discard the bad data shard window, adjust LR, and resume.
Asynchronous Distributed Checkpointing
Saving a 70B model checkpoint (1.1 TB) every 1,000 steps uses background host RAM buffering and fast parallel NVMe pipelines to prevent blocking GPU computation.
MATHEMATICAL FORMULATION · MODEL FLOPS UTILIZATION (MFU)
Measuring the ratio of achieved theoretical matrix FLOPs against maximum hardware peak specs.
REAL-WORLD PRODUCTION ENGINEERING
Meta's Llama 3 405B training run sustained 38%+ MFU across 16,384 H100 GPUs while automatically recovering from over 400 node hardware failures without manual intervention.