unsloth/studio/backend/core/training/training.py
DoubleMathew f372da407b
MLX Training updates (#5656)
* Expose MLX grad value clipping in Studio

* update test

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* dataset ordering + wd

* fix mlx smoke step expectations

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* cast norm activation output back to original input dtype

* address mlx studio review feedback

* Fix present-but-None seed override for PR #5656

studio/backend/core/training/worker.py
  `config.get("model_random_state", random_seed)` only fills the
  default when the key is absent. When a caller passes
  `config["model_random_state"] = None` explicitly (which happens
  any time a JSON payload sends an explicit `null`), the old code
  forwarded `None` to FastMLXModel and disabled deterministic init
  silently. Same for `lora_random_state`. Treat absent and explicit
  None the same way: fall back to random_seed.

studio/backend/tests/test_training_raw_support.py
  Update the source-string assertions to match the new lines.

* Guard optional MLXTrainingConfig fields and normalize random_seed for PR #5656

The MLX worker now passes `cast_norm_output_to_input_dtype` and
`dataset_order` only when the linked unsloth-zoo dataclass actually
declares them. Released zoo trees that predate the paired PR can still
construct `MLXTrainingConfig` without raising
`TypeError: unexpected keyword argument`. Once the dependency floor is
bumped to a release that contains both fields, the feature-detect
guards become no-ops.

`random_seed = config.get("random_seed", 3407)` was unguarded against
explicit `None` from raw / backend callers. The same value seeded the
trainer and was the fallback target for `model_random_state` /
`lora_random_state`. Normalize once at the top of the function and use
the normalized value everywhere so an explicit `None` cannot reach
FastMLXModel / get_peft_model / MLXTrainingConfig.

Existing seed source-pattern test updated to match the new normalize
helper. New test asserts the feature-detection guards exist and that
the unconditional kwargs do not include the gated fields.

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* Normalize seed / cast / max_grad_value at TrainingBackend for PR #5656

Round-3 review consensus: the per-field guards that landed in the MLX
worker only protect the MLX path. The same `TrainingBackend.start_training`
config still reaches the CUDA/text trainer at `worker.py:2267`, the
embedding LoRA init at `worker.py:2450`, and embedding TrainingArguments
at `worker.py:2624` with raw `None` values, so an explicit
`random_seed=None` from a raw / backend caller still breaks non-MLX
training even after the previous fix.

Move the normalization into `TrainingBackend.start_training` itself,
where it runs once for every training mode:

- `_coerce_seed(value)`: explicit `None`, non-int, or absent all become
  3407. Every downstream worker now sees an int.
- `_coerce_optional_bool(value, default)`: explicit `None` falls back
  to `default` instead of `bool(None) == False`. Also normalizes the
  common raw-config / YAML string aliases ("true" / "false" / "0" /
  "1"). Used for `cast_norm_output_to_input_dtype`.
- `_coerce_optional_nonneg_float(name, value)`: rejects negative
  numerics from raw / backend callers, matching the Pydantic
  `ge=0` constraint the HTTP route already enforces. Used for
  `max_grad_value`.

worker.py MLX path: the existing `bool(config.get(key, True))` for
`cast_norm_output_to_input_dtype` was changed to also fall back on
explicit `None`, so direct worker callers (bypassing
`TrainingBackend.start_training`) are equally safe. `max_grad_value`
also raises on negative values inside the worker for the same reason.

TrainingStartRequest.random_seed default bumped from 42 to 3407 so
direct REST callers that omit the field receive the same default as
the Studio frontend and the MLX worker.

New regression test exercises the three new helpers across explicit
None, valid values, string aliases, and negative-value rejection.

* Tighten feature-detect test paren tracking for PR #5656

The block-extraction used , which stops at the
first inner closing paren (e.g. )
and would silently miss a future unconditional
/  added later in the same dict literal. Switched to
proper paren-depth tracking so the unconditional block is checked end-to-end.

* Shorten verbose comments in MLX Studio backend

* Handle MLX Studio EOS appending by mode

* Wire MLX leaf norm clipping through Studio

* Respect VLM layer filters for explicit LoRA targets

Rationale / guardrails for the local Studio/vision push:

When callers provide explicit VLM LoRA target_modules together with layer filters, FastVisionModel still needs to route the explicit targets through get_peft_regex. Otherwise the layer filters are ignored and adapters can be attached outside the requested language/vision scope.

Do not revert this to plain list(target_modules) for explicit module lists. The CUDA/Studio-facing contract is that explicit targets and layer filters compose: target_modules selects module names, while finetune_language_layers / finetune_vision_layers / finetune_attention_modules / finetune_mlp_modules constrain where those targets are allowed.

The regression test covers the language-only explicit q_proj case and source-checks that explicit targets are wrapped through get_peft_regex when filters are active.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Refresh MLX smoke clip-config note for leaf_norm default

Trim the 11-line comment block to 5 lines and correct the stale claim
that MLXTrainingConfig defaults to max_grad_value=1.0. The new default
is max_grad_leaf_norm=1.0 (same memory profile as elementwise but
direction-preserving). The smoke still pins max_grad_value=1.0
explicitly to keep the 13-seed pass-rate fixture stable.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Forward max_grad_leaf_norm through the training route and warn when layer filters constrain explicit target_modules for PR #5656

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Daniel Han-Chen <info@unsloth.ai>
Co-authored-by: Daniel Han <danielhanchen@gmail.com>
2026-06-14 04:58:50 -07:00

1054 lines
42 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
"""
Training backend — subprocess orchestrator.
Each job runs in a fresh spawn subprocess (solving transformers version-switching);
the in-process UnslothTrainer singleton is only used inside the worker. This file
orchestrates the subprocess lifecycle, pumps events from the worker's mp.Queue, and
exposes the same API to routes/training.py. Pattern follows data_recipe/jobs/manager.py.
"""
import json as _json
import math
import multiprocessing as mp
import os
import queue
import re
import shutil
import threading
import time
import structlog
from datetime import datetime, timezone
from loggers import get_logger
from dataclasses import dataclass, field
from pathlib import Path
from typing import Optional, Tuple, Any
import matplotlib.pyplot as plt
from utils.hardware import prepare_gpu_selection
from utils.native_path_leases import (
native_path_secret_removed_for_child_start,
run_without_native_path_secret,
)
from utils.paths import outputs_root
logger = get_logger(__name__)
def _coerce_seed(value, default = 3407) -> int:
"""Normalize None / non-int to `default` (transformers.set_seed(None) raises)."""
if value is None:
return int(default)
try:
return int(value)
except (TypeError, ValueError):
return int(default)
def _coerce_optional_bool(value, default: bool) -> bool:
"""Treat explicit None as `default` instead of `bool(None) == False`."""
if value is None:
return bool(default)
if isinstance(value, str):
normalized = value.strip().lower()
if normalized in ("true", "1", "yes", "on"):
return True
if normalized in ("false", "0", "no", "off", ""):
return False
return bool(value)
def _coerce_optional_nonneg_float(name: str, value):
"""Reject negatives; HTTP `ge=0` doesn't cover raw `**kwargs` callers."""
if value is None:
return None
try:
coerced = float(value)
except (TypeError, ValueError):
raise ValueError(f"Unsloth: {name}={value!r} must be a non-negative float or None.")
if coerced < 0:
raise ValueError(f"Unsloth: {name}={coerced} must be >= 0 (use 0 or None to disable).")
return coerced
_HF_TMP_CHECKPOINT_RE = re.compile(r"^tmp-checkpoint-\d+$")
def _sanitize_db_config(config: dict[str, Any]) -> dict[str, Any]:
db_config = {
k: v for k, v in config.items() if k not in {"hf_token", "wandb_token", "s3_config"}
}
s3_config = config.get("s3_config")
if hasattr(s3_config, "model_dump"):
s3_config = s3_config.model_dump()
if isinstance(s3_config, dict) and s3_config:
db_config["dataset_source"] = "s3"
db_config["s3_dataset"] = {
"bucket": s3_config.get("bucket"),
"region": s3_config.get("region"),
"prefix": s3_config.get("prefix"),
"use_iam_role": bool(s3_config.get("use_iam_role")),
}
return db_config
def _s3_dataset_name(s3_dataset: Any) -> Optional[str]:
if not isinstance(s3_dataset, dict):
return None
bucket = s3_dataset.get("bucket")
if not bucket:
return None
prefix = s3_dataset.get("prefix")
return f"s3://{bucket}/{prefix}" if prefix else f"s3://{bucket}"
def _cleanup_cancelled_checkpoints(output_dir: str | os.PathLike) -> None:
"""Remove only HF Trainer ``tmp-checkpoint-<step>/`` partials after a cancel.
Completed ``checkpoint-<int>/`` dirs survive. Symlinked output_dir / children
are skipped so containment can't be bypassed.
"""
out = Path(output_dir)
if not out.exists() or not out.is_dir() or out.is_symlink():
return
try:
out_real = out.resolve()
out_root_real = Path(outputs_root()).resolve()
except OSError:
return
try:
out_real.relative_to(out_root_real)
except ValueError:
logger.warning(
"Skipping checkpoint cleanup - %s is not under outputs_root %s",
out_real,
out_root_real,
)
return
removed = 0
for entry in out.iterdir():
if not entry.is_dir() or entry.is_symlink():
continue
if not _HF_TMP_CHECKPOINT_RE.match(entry.name):
continue
try:
shutil.rmtree(entry, ignore_errors = False)
removed += 1
except OSError as exc:
logger.warning("Could not remove %s: %s", entry, exc)
logger.info(
"Cancelled-run cleanup removed %d in-flight tmp-checkpoint dir(s) under %s",
removed,
out,
)
_CTX = mp.get_context("spawn")
# Plot styling constants
PLOT_WIDTH = 8
PLOT_HEIGHT = 3.5
@dataclass
class TrainingProgress:
"""Mirror of trainer.TrainingProgress so the parent never imports heavy ML modules."""
epoch: float = 0
step: int = 0
total_steps: int = 0
loss: Optional[float] = None
learning_rate: Optional[float] = None
is_training: bool = False
is_completed: bool = False
error: Optional[str] = None
status_message: str = "Ready to train"
elapsed_seconds: Optional[float] = None
eta_seconds: Optional[float] = None
grad_norm: Optional[float] = None
num_tokens: Optional[int] = None
eval_loss: Optional[float] = None
peak_memory_gb: Optional[float] = None
class TrainingBackend:
"""
Training orchestration backend — subprocess-based.
Launches a fresh subprocess per job, communicates via mp.Queue.
"""
FLUSH_THRESHOLD: int = 10
def __init__(self):
# Subprocess state
self._proc: Optional[mp.Process] = None
self._event_queue: Any = None
self._stop_queue: Any = None
self._pump_thread: Optional[threading.Thread] = None
self._lock = threading.Lock()
# Progress state (updated by pump thread from subprocess events)
self._progress = TrainingProgress()
self._should_stop = False
self._cancel_requested = False # True only for stop(save=False)
# Training metrics (consumed by routes for SSE and /metrics)
self.loss_history: list = []
self.lr_history: list = []
self.step_history: list = []
self.grad_norm_history: list = []
self.grad_norm_step_history: list = []
self.eval_loss_history: list = []
self.eval_step_history: list = []
self.eval_enabled: bool = False
self.current_theme: str = "light"
# Job metadata
self.current_job_id: Optional[str] = None
self._output_dir: Optional[str] = None
# DB persistence
self._metric_buffer: list[dict] = []
self._run_finalized: bool = False
self._db_run_created: bool = False
self._db_total_steps_set: bool = False
self._db_config: Optional[dict] = None
self._db_started_at: Optional[str] = None
logger.info("TrainingBackend initialized (subprocess mode)")
# ------------------------------------------------------------------
# Public API (called by routes/training.py)
# ------------------------------------------------------------------
def start_training(self, job_id: str, **kwargs) -> bool:
"""Spawn a subprocess to run the full training pipeline.
All kwargs are serialized into a config dict and sent to the worker.
Returns True if the subprocess started successfully.
"""
with self._lock:
if self._proc is not None and self._proc.is_alive():
logger.warning("Training subprocess already running")
return False
# Join prior pump thread — refuse to start if it won't die
if self._pump_thread is not None and self._pump_thread.is_alive():
self._pump_thread.join(timeout = 5.0)
if self._pump_thread.is_alive():
logger.warning("Previous pump thread did not exit within 5s — refusing to start")
return False
self._pump_thread = None
# Build config dict for the subprocess
config = {
"model_name": kwargs["model_name"],
"training_type": kwargs.get("training_type", "LoRA/QLoRA"),
"hf_token": kwargs.get("hf_token", ""),
"load_in_4bit": kwargs.get("load_in_4bit", True),
"max_seq_length": kwargs.get("max_seq_length", 2048),
"vision_image_size": kwargs.get("vision_image_size"),
"hf_dataset": kwargs.get("hf_dataset", ""),
"local_datasets": kwargs.get("local_datasets"),
"local_eval_datasets": kwargs.get("local_eval_datasets"),
"format_type": kwargs.get("format_type", ""),
"subset": kwargs.get("subset"),
"train_split": kwargs.get("train_split", "train"),
"eval_split": kwargs.get("eval_split"),
"eval_steps": kwargs.get("eval_steps", 0.00),
"dataset_slice_start": kwargs.get("dataset_slice_start"),
"dataset_slice_end": kwargs.get("dataset_slice_end"),
"custom_format_mapping": kwargs.get("custom_format_mapping"),
"is_dataset_image": kwargs.get("is_dataset_image", False),
"is_dataset_audio": kwargs.get("is_dataset_audio", False),
"is_embedding": kwargs.get("is_embedding", False),
"num_epochs": kwargs.get("num_epochs", 3),
"learning_rate": kwargs.get("learning_rate", "2e-4"),
"embedding_learning_rate": kwargs.get("embedding_learning_rate"),
"batch_size": kwargs.get("batch_size", 2),
"gradient_accumulation_steps": kwargs.get("gradient_accumulation_steps", 4),
"warmup_steps": kwargs.get("warmup_steps"),
"warmup_ratio": kwargs.get("warmup_ratio"),
"max_steps": kwargs.get("max_steps", 0),
"save_steps": kwargs.get("save_steps", 0),
"weight_decay": kwargs.get("weight_decay", 0.001),
"max_grad_norm": kwargs.get("max_grad_norm", 0.0),
"max_grad_value": _coerce_optional_nonneg_float(
"max_grad_value", kwargs.get("max_grad_value")
),
"max_grad_leaf_norm": _coerce_optional_nonneg_float(
"max_grad_leaf_norm", kwargs.get("max_grad_leaf_norm")
),
"cast_norm_output_to_input_dtype": _coerce_optional_bool(
kwargs.get("cast_norm_output_to_input_dtype"), True
),
# MLX/CUDA/embedding workers need an int (transformers.set_seed(None) raises).
"random_seed": _coerce_seed(kwargs.get("random_seed")),
"packing": kwargs.get("packing", False),
"optim": kwargs.get("optim", "adamw_8bit"),
"lr_scheduler_type": kwargs.get("lr_scheduler_type", "linear"),
"use_lora": kwargs.get("use_lora", True),
"lora_r": kwargs.get("lora_r", 16),
"lora_alpha": kwargs.get("lora_alpha", 16),
"lora_dropout": kwargs.get("lora_dropout", 0.0),
"target_modules": kwargs.get("target_modules"),
"gradient_checkpointing": kwargs.get("gradient_checkpointing", "unsloth"),
"use_rslora": kwargs.get("use_rslora", False),
"use_loftq": kwargs.get("use_loftq", False),
"train_on_completions": kwargs.get("train_on_completions", False),
"finetune_vision_layers": kwargs.get("finetune_vision_layers", True),
"finetune_language_layers": kwargs.get("finetune_language_layers", True),
"finetune_attention_modules": kwargs.get("finetune_attention_modules", True),
"finetune_mlp_modules": kwargs.get("finetune_mlp_modules", True),
"enable_wandb": kwargs.get("enable_wandb", False),
"wandb_token": kwargs.get("wandb_token"),
"wandb_project": kwargs.get("wandb_project", "unsloth-training"),
"enable_tensorboard": kwargs.get("enable_tensorboard", False),
"tensorboard_dir": kwargs.get("tensorboard_dir", "runs"),
"resume_from_checkpoint": kwargs.get("resume_from_checkpoint"),
"trust_remote_code": kwargs.get("trust_remote_code", False),
"gpu_ids": kwargs.get("gpu_ids"),
"s3_config": kwargs.get("s3_config"),
}
# Full finetuning always runs in 16-bit; LoRA/QLoRA/CPT keep the request.
if config["training_type"] == "Full Finetuning":
config["load_in_4bit"] = False
# Spawn into locals so state is untouched on failure.
from utils.hardware import hardware as _hw
if _hw.DEVICE == _hw.DeviceType.MLX:
config["resolved_gpu_ids"] = None
config["gpu_selection"] = None
else:
resolved_gpu_ids, gpu_selection = prepare_gpu_selection(
kwargs.get("gpu_ids"),
model_name = config["model_name"],
hf_token = config["hf_token"] or None,
training_type = config["training_type"],
load_in_4bit = config["load_in_4bit"],
batch_size = config.get("batch_size", 4),
max_seq_length = config.get("max_seq_length", 2048),
lora_rank = config.get("lora_r", 16),
target_modules = config.get("target_modules"),
gradient_checkpointing = config.get("gradient_checkpointing", "unsloth"),
optimizer = config.get("optim", "adamw_8bit"),
)
config["resolved_gpu_ids"] = resolved_gpu_ids
config["gpu_selection"] = gpu_selection
from .worker import run_training_process
try:
with native_path_secret_removed_for_child_start():
event_queue = _CTX.Queue()
stop_queue = _CTX.Queue()
proc = _CTX.Process(
target = run_without_native_path_secret,
args = (run_training_process,),
kwargs = {
"event_queue": event_queue,
"stop_queue": stop_queue,
"config": config,
},
daemon = True,
)
proc.start()
except Exception:
logger.error("Failed to start training subprocess", exc_info = True)
return False
logger.info("Training subprocess started (pid=%s)", proc.pid)
# Reset state (old pump thread dead, proc.start() succeeded).
self.current_job_id = job_id
self._should_stop = False
self._cancel_requested = False
self._progress = TrainingProgress(
is_training = True, status_message = "Initializing training..."
)
self.loss_history.clear()
self.lr_history.clear()
self.step_history.clear()
self.grad_norm_history.clear()
self.grad_norm_step_history.clear()
self.eval_loss_history.clear()
self.eval_step_history.clear()
self.eval_enabled = False
self._output_dir = None
self._metric_buffer.clear()
self._run_finalized = False
self._db_run_created = False
self._db_total_steps_set = False
self._db_config = _sanitize_db_config(config)
self._db_started_at = datetime.now(timezone.utc).isoformat()
# Assign subprocess handles after state reset.
self._event_queue = event_queue
self._stop_queue = stop_queue
self._proc = proc
# Eagerly create DB run row so it appears in history during model loading.
self._ensure_db_run_created()
self._pump_thread = threading.Thread(target = self._pump_loop, daemon = True)
self._pump_thread.start()
return True
def stop_training(self, save: bool = True) -> bool:
"""Send stop signal to the training subprocess."""
self._should_stop = True
if not save:
self._cancel_requested = True
with self._lock:
if self._stop_queue is not None:
try:
self._stop_queue.put({"type": "stop", "save": save})
except (OSError, ValueError):
pass
# Update progress immediately for responsive UI.
self._progress.status_message = (
"Stopping training and saving checkpoint..." if save else "Cancelling training..."
)
return True
def force_terminate(self) -> None:
"""Force-kill the training subprocess so state can be reset immediately."""
with self._lock:
if self._proc is not None and self._proc.is_alive():
logger.info("Force-terminating training subprocess (pid=%s)", self._proc.pid)
self._proc.terminate()
proc = self._proc
cancelled = self._cancel_requested
output_dir = self._output_dir
if proc is not None:
proc.join(timeout = 5.0)
if proc.is_alive():
proc.kill()
proc.join(timeout = 2.0)
# Wait for pump thread to finish DB finalization (8s covers SQLite's 5s lock timeout).
if self._pump_thread is not None and self._pump_thread.is_alive():
self._pump_thread.join(timeout = 8.0)
if cancelled and output_dir:
try:
_cleanup_cancelled_checkpoints(output_dir)
except Exception:
logger.exception(
"Failed to clean up cancelled-run checkpoints under %s",
output_dir,
)
def is_training_active(self) -> bool:
"""Check if training is currently active."""
with self._lock:
if self._proc is not None and self._proc.is_alive():
return True
if self._should_stop:
return False
p = self._progress
if p.is_training:
return True
if p.is_completed or p.error:
return False
# Infer activity from the status message.
status_lower = (p.status_message or "").lower()
if any(
k in status_lower
for k in [
"cancelled",
"canceled",
"stopped",
"completed",
"ready to train",
]
):
return False
if any(
k in status_lower
for k in [
"loading",
"preparing",
"training",
"configuring",
"tokenizing",
"starting",
"importing",
]
):
return True
return False
def get_training_status(self, theme: str = "light") -> Tuple:
"""Get current training status and loss plot."""
with self._lock:
progress = self._progress
if not (progress.is_training or progress.is_completed or progress.error):
return (None, progress)
plot = self._create_loss_plot(progress, theme)
return (plot, progress)
def refresh_plot_for_theme(self, theme: str) -> Optional[plt.Figure]:
"""Refresh plot with new theme."""
if theme and isinstance(theme, str) and theme in ["light", "dark"]:
self.current_theme = theme
if self.loss_history:
with self._lock:
progress = self._progress
return self._create_loss_plot(progress, self.current_theme)
return None
# ------------------------------------------------------------------
# Compatibility shims — routes/training.py accesses these
# ------------------------------------------------------------------
class _TrainerShim:
"""Minimal shim so routes that access backend.trainer.* still work."""
def __init__(self, backend: "TrainingBackend"):
self._backend = backend
self.should_stop = False
@property
def training_progress(self):
return self._backend._progress
@training_progress.setter
def training_progress(self, value):
self._backend._progress = value
def get_training_progress(self):
return self._backend._progress
def _update_progress(self, **kwargs):
with self._backend._lock:
for key, value in kwargs.items():
if hasattr(self._backend._progress, key):
setattr(self._backend._progress, key, value)
@property
def trainer(self):
"""Compatibility shim for routes that access backend.trainer.*"""
return self._TrainerShim(self)
# ------------------------------------------------------------------
# Event pump (background thread)
# ------------------------------------------------------------------
def _pump_loop(self) -> None:
"""Background thread: consume events from subprocess → update state."""
while True:
if self._proc is None or self._event_queue is None:
return
event = self._read_queue(self._event_queue, timeout_sec = 0.25)
if event is not None:
self._handle_event(event)
continue
if self._proc.is_alive():
continue
# Process exited — drain remaining events.
for e in self._drain_queue(self._event_queue):
self._handle_event(e)
# Mark done if no explicit complete/error was received.
with self._lock:
if self._progress.is_training:
if self._should_stop:
self._progress.is_training = False
self._progress.status_message = "Training stopped."
else:
self._progress.is_training = False
self._progress.error = (
self._progress.error or "Training process exited unexpectedly"
)
self._ensure_db_run_created()
self._finalize_run_in_db(
status = "stopped" if self._should_stop else "error",
error_message = None
if self._should_stop
else "Training process terminated unexpectedly",
)
return
def _handle_event(self, event: dict) -> None:
"""Apply a subprocess event to local state.
State updates happen inside self._lock; DB I/O happens after releasing
it so status-polling endpoints aren't blocked by slow SQLite writes.
"""
etype = event.get("type")
db_action: Optional[str] = None
db_action_kwargs: dict = {}
with self._lock:
if etype == "progress":
self._progress.step = event.get("step", self._progress.step)
self._progress.epoch = event.get("epoch", self._progress.epoch)
# loss/lr sanitized below.
_raw_loss = event.get("loss")
_raw_lr = event.get("learning_rate")
try:
_safe_loss = float(_raw_loss) if _raw_loss is not None else None
except (TypeError, ValueError):
logger.debug("Could not convert loss to float: %s", _raw_loss)
_safe_loss = None
_loss_is_nonfinite = _safe_loss is not None and not math.isfinite(_safe_loss)
if _loss_is_nonfinite:
# Drop the value rather than laundering it back to the last
# finite loss; clients see loss=None at this step so the NaN
# is not hidden behind a stale value. Training continues.
_safe_loss = None
if not getattr(self._progress, "_nonfinite_loss_warned", False):
self._progress._nonfinite_loss_warned = True
logger.warning(
"Training produced non-finite loss at step %s; "
"loss field will report null until it recovers.",
event.get("step", "?"),
)
try:
_safe_lr = float(_raw_lr) if _raw_lr is not None else None
except (TypeError, ValueError):
logger.debug("Could not convert learning_rate to float: %s", _raw_lr)
_safe_lr = None
if _safe_lr is not None and not math.isfinite(_safe_lr):
_safe_lr = None
if _safe_loss is not None:
self._progress.loss = _safe_loss
elif _loss_is_nonfinite:
# Clear stale finite loss so the API doesn't keep
# reporting the last good value while NaN is happening.
self._progress.loss = None
if _safe_lr is not None:
self._progress.learning_rate = _safe_lr
self._progress.total_steps = event.get("total_steps", self._progress.total_steps)
self._progress.elapsed_seconds = event.get("elapsed_seconds")
self._progress.eta_seconds = event.get("eta_seconds")
self._progress.grad_norm = event.get("grad_norm")
self._progress.num_tokens = event.get("num_tokens")
self._progress.eval_loss = event.get("eval_loss")
_peak = event.get("peak_memory_gb")
if _peak is not None:
try:
self._progress.peak_memory_gb = float(_peak)
except (TypeError, ValueError):
pass
self._progress.is_training = True
status = event.get("status_message", "")
if status:
self._progress.status_message = status
# Update metric histories using sanitized values.
step = event.get("step", 0)
loss = _safe_loss
lr = _safe_lr
if step > 0 and loss is not None:
self.loss_history.append(loss)
self.lr_history.append(lr if lr is not None else 0.0)
self.step_history.append(step)
grad_norm = event.get("grad_norm")
gn = None
if grad_norm is not None:
try:
gn = float(grad_norm)
except (TypeError, ValueError):
gn = None
if step > 0 and gn is not None and math.isfinite(gn):
self.grad_norm_history.append(gn)
self.grad_norm_step_history.append(step)
else:
gn = None
eval_loss = event.get("eval_loss")
if eval_loss is not None:
try:
eval_loss = float(eval_loss)
except (TypeError, ValueError):
logger.debug("Could not convert eval_loss to float: %s", eval_loss)
eval_loss = None
if step > 0 and eval_loss is not None and math.isfinite(eval_loss):
self.eval_loss_history.append(eval_loss)
self.eval_step_history.append(step)
self.eval_enabled = True
else:
eval_loss = None
# Buffer metric for DB flush.
self._metric_buffer.append(
{
"step": step,
"loss": loss,
"learning_rate": lr,
"grad_norm": gn,
"eval_loss": eval_loss,
"epoch": event.get("epoch"),
"num_tokens": event.get("num_tokens"),
"elapsed_seconds": event.get("elapsed_seconds"),
}
)
# Pick the DB action to run after releasing the lock.
if not self._db_run_created and self.current_job_id and self._db_config:
db_action = "create_run"
db_action_kwargs = {
"job_id": self.current_job_id,
"model_name": self._db_config["model_name"],
"dataset_name": self._db_config.get("hf_dataset")
or next(iter(self._db_config.get("local_datasets") or []), "unknown"),
"config_json": _json.dumps(self._db_config),
"started_at": self._db_started_at or datetime.now(timezone.utc).isoformat(),
"total_steps": event.get("total_steps"),
}
elif (
event.get("total_steps")
and self._db_run_created
and not self._db_total_steps_set
):
db_action = "update_total_steps"
db_action_kwargs = {
"job_id": self.current_job_id,
"total_steps": event["total_steps"],
}
elif len(self._metric_buffer) >= self.FLUSH_THRESHOLD:
db_action = "flush"
elif etype == "eval_configured":
self.eval_enabled = True
elif etype == "status":
self._progress.status_message = event.get("message", "")
self._progress.is_training = True
elif etype == "complete":
self._progress.is_training = False
self._progress.is_completed = True
self._output_dir = event.get("output_dir")
msg = event.get("status_message", "Training completed")
self._progress.status_message = msg
if not self._db_run_created and self.current_job_id and self._db_config:
db_action = "create_and_finalize"
else:
db_action = "finalize"
db_action_kwargs = {
"status": "stopped" if self._should_stop else "completed",
"output_dir": self._output_dir,
}
elif etype == "error":
self._progress.is_training = False
self._progress.error = event.get("error", "Unknown error")
logger.error("Training error: %s", event.get("error"))
stack = event.get("stack", "")
if stack:
logger.error("Stack trace:\n%s", stack)
if not self._db_run_created and self.current_job_id and self._db_config:
db_action = "create_and_finalize"
else:
db_action = "finalize"
db_action_kwargs = {
"status": "stopped" if self._should_stop else "error",
"error_message": event.get("error", "Unknown error"),
}
# --- DB I/O outside the lock ---
if db_action == "create_run":
try:
from storage.studio_db import create_run
create_run(
id = db_action_kwargs["job_id"],
model_name = db_action_kwargs["model_name"],
dataset_name = db_action_kwargs["dataset_name"],
config_json = db_action_kwargs["config_json"],
started_at = db_action_kwargs["started_at"],
total_steps = db_action_kwargs["total_steps"],
)
self._db_run_created = True
if db_action_kwargs["total_steps"]:
self._db_total_steps_set = True
except Exception:
logger.warning("Failed to create DB run record", exc_info = True)
elif db_action == "create_and_finalize":
self._ensure_db_run_created()
self._finalize_run_in_db(**db_action_kwargs)
elif db_action == "update_total_steps":
try:
from storage.studio_db import update_run_total_steps
update_run_total_steps(db_action_kwargs["job_id"], db_action_kwargs["total_steps"])
self._db_total_steps_set = True
except Exception:
logger.warning("Failed to update total_steps in DB", exc_info = True)
elif db_action == "flush":
self._flush_metrics_to_db()
elif db_action == "finalize":
self._finalize_run_in_db(**db_action_kwargs)
def _ensure_db_run_created(self) -> None:
"""Create the DB row if it doesn't exist yet. Called outside the lock."""
if self._db_run_created or not self.current_job_id or not self._db_config:
return
try:
from storage.studio_db import create_run
dataset_name = (
self._db_config.get("hf_dataset")
or next(iter(self._db_config.get("local_datasets") or []), None)
or _s3_dataset_name(self._db_config.get("s3_dataset"))
or "unknown"
)
create_run(
id = self.current_job_id,
model_name = self._db_config["model_name"],
dataset_name = dataset_name,
config_json = _json.dumps(self._db_config),
started_at = self._db_started_at or datetime.now(timezone.utc).isoformat(),
total_steps = self._progress.total_steps or None,
)
self._db_run_created = True
except Exception:
logger.warning("Failed to create DB run record for early failure", exc_info = True)
def _finalize_run_in_db(
self,
status: str,
error_message: Optional[str] = None,
output_dir: Optional[str] = None,
) -> None:
"""Flush remaining metrics and mark a run as finished in the DB."""
if not self.current_job_id or not self._db_run_created or self._run_finalized:
return
self._flush_metrics_to_db()
try:
from storage.studio_db import finish_run
from utils.downsample import downsample
sparkline = downsample(self.loss_history, 50)
finish_run(
id = self.current_job_id,
status = status,
ended_at = datetime.now(timezone.utc).isoformat(),
final_step = self._progress.step,
final_loss = self._progress.loss
if (self._progress.loss is not None and math.isfinite(self._progress.loss))
else None,
duration_seconds = self._progress.elapsed_seconds,
loss_sparkline = _json.dumps(sparkline),
output_dir = output_dir,
error_message = error_message,
)
self._run_finalized = True
except Exception:
logger.warning("Failed to finalize run in DB (status=%s)", status, exc_info = True)
def _flush_metrics_to_db(self) -> None:
"""Flush buffered metrics to the database and update live progress."""
if not self._metric_buffer or not self.current_job_id or not self._db_run_created:
return
# Cap buffer to bound memory growth.
if len(self._metric_buffer) > 500:
logger.warning(
"Metric buffer exceeded 500 entries (%d) — trimming oldest",
len(self._metric_buffer),
)
self._metric_buffer = self._metric_buffer[-500:]
# Snapshot before insert so metrics arriving during the write survive.
batch = list(self._metric_buffer)
try:
from storage.studio_db import insert_metrics_batch, update_run_progress
insert_metrics_batch(self.current_job_id, batch)
del self._metric_buffer[: len(batch)]
update_run_progress(
id = self.current_job_id,
step = self._progress.step,
loss = self._progress.loss
if (self._progress.loss is not None and math.isfinite(self._progress.loss))
else None,
duration_seconds = self._progress.elapsed_seconds,
)
except Exception:
# Leave buffer intact for retry on next flush
logger.warning("Failed to flush metrics to DB", exc_info = True)
@staticmethod
def _read_queue(q: Any, timeout_sec: float) -> Optional[dict]:
try:
return q.get(timeout = timeout_sec)
except queue.Empty:
return None
except (EOFError, OSError, ValueError):
return None
@staticmethod
def _drain_queue(q: Any) -> list:
events = []
while True:
try:
events.append(q.get_nowait())
except queue.Empty:
return events
except (EOFError, OSError, ValueError):
return events
# ------------------------------------------------------------------
# Plot generation
# ------------------------------------------------------------------
def _create_loss_plot(
self,
progress: TrainingProgress,
theme: str = "light",
) -> plt.Figure:
"""Create training loss plot with theme-aware styling."""
plt.close("all")
LIGHT_STYLE = {
"facecolor": "#ffffff",
"grid_color": "#d1d5db",
"line": "#16b88a",
"text": "#1f2937",
"empty_text": "#6b7280",
}
DARK_STYLE = {
"facecolor": "#292929",
"grid_color": "#404040",
"line": "#4ade80",
"text": "#e5e7eb",
"empty_text": "#9ca3af",
}
style = LIGHT_STYLE if theme == "light" else DARK_STYLE
fig, ax = plt.subplots(figsize = (PLOT_WIDTH, PLOT_HEIGHT))
fig.patch.set_facecolor(style["facecolor"])
ax.set_facecolor(style["facecolor"])
if self.loss_history:
steps = self.step_history
losses = self.loss_history
scatter_color = "#60a5fa"
ax.scatter(
steps,
losses,
s = 16,
alpha = 0.6,
color = scatter_color,
linewidths = 0,
label = "Training Loss (raw)",
)
MA_WINDOW = 20
window = min(MA_WINDOW, len(losses))
if window >= 2:
cumsum = [0.0]
for v in losses:
cumsum.append(cumsum[-1] + float(v))
ma = []
for i in range(len(losses)):
start = max(0, i - window + 1)
denom = i - start + 1
ma.append((cumsum[i + 1] - cumsum[start]) / denom)
ax.plot(
steps,
ma,
color = style["line"],
linewidth = 2.5,
alpha = 0.95,
label = f"Moving Avg ({ma[-1]:.4f})",
)
leg = ax.legend(frameon = False, fontsize = 9)
for t in leg.get_texts():
t.set_color(style["text"])
ax.set_xlabel("Steps", fontsize = 10, color = style["text"])
ax.set_ylabel("Loss", fontsize = 10, color = style["text"])
if progress.error:
title = f"Error: {progress.error}"
elif progress.is_completed:
loss_str = f"{progress.loss:.4f}" if progress.loss is not None else "--"
title = f"Training completed! Final loss: {loss_str}"
elif progress.status_message:
title = progress.status_message
elif progress.step > 0:
loss_str = f"{progress.loss:.4f}" if progress.loss is not None else "--"
title = f"Epoch: {progress.epoch} | Step: {progress.step}/{progress.total_steps} | Loss: {loss_str}"
else:
title = "Training Loss"
ax.set_title(title, fontsize = 11, fontweight = "bold", pad = 10, color = style["text"])
ax.grid(True, alpha = 0.4, linestyle = "--", color = style["grid_color"])
ax.tick_params(colors = style["text"], which = "both")
ax.spines["top"].set_visible(False)
ax.spines["right"].set_visible(False)
ax.spines["bottom"].set_color(style["text"])
ax.spines["left"].set_color(style["text"])
else:
display_msg = (
progress.status_message
if progress.status_message
else "Waiting for training data..."
)
ax.text(
0.5,
0.5,
display_msg,
ha = "center",
va = "center",
fontsize = 16,
color = style["empty_text"],
transform = ax.transAxes,
)
ax.set_xticks([])
ax.set_yticks([])
for spine in ax.spines.values():
spine.set_visible(False)
fig.tight_layout()
return fig
def _transfer_to_inference_backend(self) -> bool:
"""Transfer model to inference backend.
No-op: with subprocess training the model is freed on exit, so inference
must load from the saved checkpoint on disk.
"""
logger.info(
"_transfer_to_inference_backend: subprocess training — "
"model must be loaded from disk (output_dir=%s)",
self._output_dir,
)
return False
# ========== GLOBAL INSTANCE ==========
_training_backend = None
def get_training_backend() -> TrainingBackend:
"""Get global training backend instance"""
global _training_backend
if _training_backend is None:
_training_backend = TrainingBackend()
return _training_backend