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fix: nemotron_nano_9b_squad_peft checkpoint robustness thresholds#1944

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fix: nemotron_nano_9b_squad_peft checkpoint robustness thresholds#1944
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@adil-a adil-a commented Apr 21, 2026

Summary

Fixes nemotron_nano_9b_squad_peft checkpoint robustness CI job (pipeline 48953745, job 301287621). Same Mamba-hybrid save/reload non-determinism that affects the SFT sibling (#1943) also hits the PEFT path. save_consolidated: true serializes and reloads the full NemotronH base (Mamba2 mixer state) regardless of whether a LoRA adapter is attached, so Phase 3 automodel-from-consolidated KL is ~1.7e-3 (>0) — identical class of failure as the SFT run.

Applies the same four YAML fixes as #1943:

  • kl_threshold=5e-3 (~3x observed 1.7e-3)
  • trust_remote_code=true so Phase 4's vanilla-HF load of nvidia/NVIDIA-Nemotron-Nano-9B-v2 uses the repo-shipped configuration_nemotron_h.py (transformers 5.5.4's builtin _pattern_to_list raises KeyError('-') on the hybrid pattern)
  • no_check_resume=true (Mamba hybrid resume is non-deterministic, matches the nemotron_nano_8b_v1_squad precedent)
  • dist_env.timeout_minutes: 1 -> 20 so Phase 4's rank-0-only base-model + adapter merge load doesn't trip the 60s NCCL barrier on other ranks

No code changes.

Test plan

  • Reproduced CI failure byte-identically on cw-dfw 8xH100: Phase 3 max KL = 1.732453e-03 (CI: 1.401710e-03), same class of failure.
  • Verified fix: Phase 3 max KL = 1.441502e-03 (≤ 5e-3), Phase 4 max KL = 7.076394e-04 (≤ 5e-3), 1 passed, 26 warnings in 142.18s.

🤖 Generated with Claude Code

@adil-a @claude
fix: nemotron_nano_9b_squad_peft checkpoint robustness thresholds
64e095b 
Same Mamba-hybrid save/reload non-determinism that affects the SFT
sibling (#1943) also hits the PEFT path: Phase 3 `automodel-from-
consolidated` KL is ~1.7e-3 (>0) because `save_consolidated: true`
still serializes and reloads the full NemotronH base (Mamba2 mixer
state), independent of LoRA. Apply the same four YAML fixes:

- kl_threshold=5e-3 (~3x observed 1.7e-3)
- trust_remote_code=True so Phase 4's vanilla-HF load of
  nvidia/NVIDIA-Nemotron-Nano-9B-v2 uses the repo-shipped
  configuration_nemotron_h.py (transformers 5.5.4's builtin
  _pattern_to_list raises KeyError('-') on the hybrid pattern)
- no_check_resume=True (Mamba hybrid resume is inherently
  non-deterministic, matches nemotron_nano_8b_v1_squad precedent)
- dist_env.timeout_minutes 1 -> 20 so Phase 4's rank-0-only base
  model + adapter merge load doesn't trip the 60s NCCL barrier

Verified on cw-dfw 8xH100 (TP=2, transformers 5.5.4, CI launcher
overrides): Phase 3 max KL = 1.441502e-03, Phase 4 max KL =
7.076394e-04, `1 passed`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: adil-a <adil.asif2000@hotmail.com>
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adil-a commented Apr 21, 2026

Superseded by #1971 (batched pipeline-48953745 fixes). Threshold/flag change for this recipe is included in that PR.

@adil-a adil-a closed this Apr 21, 2026
akoumpa added a commit that referenced this pull request Apr 22, 2026
@adil-a @akoumpa
fix: batch ckpt-robustness fixes for pipeline 48953745 (supersedes 9 …
0322787 
…PRs) (#1971)

* fix: unify hf_kl_threshold to 1e-1 for v5.5 transformers Phase 4 drift (pipeline 48953745)

Transformers v5.5 (#1734) introduced small forward-pass changes in
Llama/Gemma/Qwen that widen the observed Phase 4 HF KL without
changing correctness. Four recipes in pipeline 48953745 were failing the
pre-existing tight bounds for this reason; authors opened separate PRs
with per-recipe thresholds.

Unify the bound at 1e-1 so the whole family passes under one policy.
Observed Phase 4 KLs on the current nightly sqsh
(automodel_nightly_21-4-2026.sqsh) for reference:
- gemma_3_270m_squad             : 2.91e-2 (was 6e-3)
- gemma_3_270m_squad_peft        : 1.68e-2 (was 8e-3)
- qwen3_moe_30b_hellaswag        : 2.43e-2 (was 1e-2)
- customizer_nemotron_nano_full_sft_chat: already 1e-1 (was 7e-2)

All comfortably under the new 1e-1 bound (3-4x margin on the tightest).

Supersedes #1932, #1933, #1939, #1942.

Signed-off-by: adil-a <adil.asif2000@hotmail.com>

* fix: ckpt-robustness Phase 3 / resume / GBS-divisibility fixes for pipeline 48953745

Adds known-good test-harness flags for model families where the checkpoint
robustness test was failing for reasons other than Phase 4 threshold drift:

nemotron_nano_9b_squad{,_peft} (Mamba hybrid):
  - dist_env.timeout_minutes: 1 -> 20 (short timeout triggered on slow init)
  - ci.checkpoint_robustness.kl_threshold: 5e-3 (Phase 3 non-det from Mamba
    SSM state under FSDP all-reduce)
  - ci.checkpoint_robustness.trust_remote_code: true
  - ci.checkpoint_robustness.no_check_resume: true (Mamba resume non-det)

ministral3_3b_squad{,_peft} (FP8 + FSDP2):
  - ci.checkpoint_robustness.kl_threshold: 5e-3 (FP8 scalar scale params
    under FSDP2 aren't losslessly round-trippable)
  - ci.checkpoint_robustness.no_check_resume: true

nemotron_super_v3_hellaswag (multi-node DP=32):
  - ci.checkpoint_robustness.step_scheduler.global_batch_size: 64
    (prior gbs wasn't divisible by DP=32)

Supersedes #1943, #1944, #1946, #1947, #1949.

Signed-off-by: adil-a <adil.asif2000@hotmail.com>

* Apply suggestions from code review

Co-authored-by: Alexandros Koumparoulis <153118171+akoumpa@users.noreply.github.com>

---------

Signed-off-by: adil-a <adil.asif2000@hotmail.com>
Co-authored-by: Alexandros Koumparoulis <153118171+akoumpa@users.noreply.github.com>
akoumpa added a commit that referenced this pull request Apr 22, 2026
@svcnvidia-nemo-ci @adil-a @akoumpa
cp: `fix: batch ckpt-robustness fixes for pipeline 48953745 (supersed…
0364ea8 
…es 9 PRs) (1971)` into `r0.4.0` (#1979)

fix: batch ckpt-robustness fixes for pipeline 48953745 (supersedes 9 PRs) (#1971)

* fix: unify hf_kl_threshold to 1e-1 for v5.5 transformers Phase 4 drift (pipeline 48953745)

Transformers v5.5 (#1734) introduced small forward-pass changes in
Llama/Gemma/Qwen that widen the observed Phase 4 HF KL without
changing correctness. Four recipes in pipeline 48953745 were failing the
pre-existing tight bounds for this reason; authors opened separate PRs
with per-recipe thresholds.

Unify the bound at 1e-1 so the whole family passes under one policy.
Observed Phase 4 KLs on the current nightly sqsh
(automodel_nightly_21-4-2026.sqsh) for reference:
- gemma_3_270m_squad             : 2.91e-2 (was 6e-3)
- gemma_3_270m_squad_peft        : 1.68e-2 (was 8e-3)
- qwen3_moe_30b_hellaswag        : 2.43e-2 (was 1e-2)
- customizer_nemotron_nano_full_sft_chat: already 1e-1 (was 7e-2)

All comfortably under the new 1e-1 bound (3-4x margin on the tightest).

Supersedes #1932, #1933, #1939, #1942.



* fix: ckpt-robustness Phase 3 / resume / GBS-divisibility fixes for pipeline 48953745

Adds known-good test-harness flags for model families where the checkpoint
robustness test was failing for reasons other than Phase 4 threshold drift:

nemotron_nano_9b_squad{,_peft} (Mamba hybrid):
  - dist_env.timeout_minutes: 1 -> 20 (short timeout triggered on slow init)
  - ci.checkpoint_robustness.kl_threshold: 5e-3 (Phase 3 non-det from Mamba
    SSM state under FSDP all-reduce)
  - ci.checkpoint_robustness.trust_remote_code: true
  - ci.checkpoint_robustness.no_check_resume: true (Mamba resume non-det)

ministral3_3b_squad{,_peft} (FP8 + FSDP2):
  - ci.checkpoint_robustness.kl_threshold: 5e-3 (FP8 scalar scale params
    under FSDP2 aren't losslessly round-trippable)
  - ci.checkpoint_robustness.no_check_resume: true

nemotron_super_v3_hellaswag (multi-node DP=32):
  - ci.checkpoint_robustness.step_scheduler.global_batch_size: 64
    (prior gbs wasn't divisible by DP=32)

Supersedes #1943, #1944, #1946, #1947, #1949.



* Apply suggestions from code review



---------

Signed-off-by: adil-a <adil.asif2000@hotmail.com>
Signed-off-by: NeMo Bot <nemo-bot@nvidia.com>
Co-authored-by: Adil <47084919+adil-a@users.noreply.github.com>
Co-authored-by: Alexandros Koumparoulis <153118171+akoumpa@users.noreply.github.com>
linnanwang pushed a commit that referenced this pull request Apr 24, 2026
@adil-a @akoumpa @linnanwang
fix: batch ckpt-robustness fixes for pipeline 48953745 (supersedes 9 …
b0a5aab 
…PRs) (#1971)

* fix: unify hf_kl_threshold to 1e-1 for v5.5 transformers Phase 4 drift (pipeline 48953745)

Transformers v5.5 (#1734) introduced small forward-pass changes in
Llama/Gemma/Qwen that widen the observed Phase 4 HF KL without
changing correctness. Four recipes in pipeline 48953745 were failing the
pre-existing tight bounds for this reason; authors opened separate PRs
with per-recipe thresholds.

Unify the bound at 1e-1 so the whole family passes under one policy.
Observed Phase 4 KLs on the current nightly sqsh
(automodel_nightly_21-4-2026.sqsh) for reference:
- gemma_3_270m_squad             : 2.91e-2 (was 6e-3)
- gemma_3_270m_squad_peft        : 1.68e-2 (was 8e-3)
- qwen3_moe_30b_hellaswag        : 2.43e-2 (was 1e-2)
- customizer_nemotron_nano_full_sft_chat: already 1e-1 (was 7e-2)

All comfortably under the new 1e-1 bound (3-4x margin on the tightest).

Supersedes #1932, #1933, #1939, #1942.

Signed-off-by: adil-a <adil.asif2000@hotmail.com>

* fix: ckpt-robustness Phase 3 / resume / GBS-divisibility fixes for pipeline 48953745

Adds known-good test-harness flags for model families where the checkpoint
robustness test was failing for reasons other than Phase 4 threshold drift:

nemotron_nano_9b_squad{,_peft} (Mamba hybrid):
  - dist_env.timeout_minutes: 1 -> 20 (short timeout triggered on slow init)
  - ci.checkpoint_robustness.kl_threshold: 5e-3 (Phase 3 non-det from Mamba
    SSM state under FSDP all-reduce)
  - ci.checkpoint_robustness.trust_remote_code: true
  - ci.checkpoint_robustness.no_check_resume: true (Mamba resume non-det)

ministral3_3b_squad{,_peft} (FP8 + FSDP2):
  - ci.checkpoint_robustness.kl_threshold: 5e-3 (FP8 scalar scale params
    under FSDP2 aren't losslessly round-trippable)
  - ci.checkpoint_robustness.no_check_resume: true

nemotron_super_v3_hellaswag (multi-node DP=32):
  - ci.checkpoint_robustness.step_scheduler.global_batch_size: 64
    (prior gbs wasn't divisible by DP=32)

Supersedes #1943, #1944, #1946, #1947, #1949.

Signed-off-by: adil-a <adil.asif2000@hotmail.com>

* Apply suggestions from code review

Co-authored-by: Alexandros Koumparoulis <153118171+akoumpa@users.noreply.github.com>

---------

Signed-off-by: adil-a <adil.asif2000@hotmail.com>
Co-authored-by: Alexandros Koumparoulis <153118171+akoumpa@users.noreply.github.com>
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