unsloth/studio/backend/core/training/training.py
Daniel Han d79fd92798
studio: scope cancel-cleanup to in-flight tmp dirs; walk back tool_call_id (#5488)
* studio: scope cancel-cleanup to in-flight tmp dirs; walk back tool_call_id

Two follow-ups to #5375's training and chat hardening.

_cleanup_cancelled_checkpoints used to rmtree every checkpoint-N
directory on Cancel. That is the opposite of what the user expects.
A user cancelling an 8h run with save_steps=2000 loses every
completed checkpoint they could have resumed from. The 67 MB residue
the audit memo flagged is the HF Trainer atomic-rename partial
(tmp-checkpoint-N), not the completed ones. The cleanup now targets
only tmp-checkpoint subdirs; completed checkpoint-N directories are
user-owned and stay. Symlinked output_dir and symlinked children are
skipped so the realpath containment cannot be levered into deleting
arbitrary content via a symlink trick.

ChatMessage._validate_role_shape stamped a random secrets.token_hex
id on tool messages with no tool_call_id. That id is uncorrelated
with the prior assistant tool_calls id, so strict passthrough
backends (OpenAI, Anthropic) reject the request as orphaned and
llama.cpp treats the tool result as "no preceding call" and
hallucinates. The synthesis moves up to ChatCompletionRequest, where
the whole conversation is visible: for each tool message missing an
id we walk back to the most recent assistant turn with tool_calls
(stopping at user turns), prefer a function.name match, otherwise
take the first unconsumed tool_call. Synthesis is the fallback when
no candidate assistant turn exists, preserving the prior round-trip
guarantee for orphaned tool messages.

Tests:
  - test_cleanup_cancelled_checkpoints.py (new): pins that completed
    checkpoint subdirs survive, tmp-checkpoint partials are removed,
    non-int suffixes (checkpoint-final, checkpoint-best) are left
    alone, output_dir outside outputs_root is refused, symlinked
    output_dir and symlinked child are both skipped, missing dir is
    a no-op.
  - test_inference_model_validation.py: 6 new walkback cases covering
    name-match preference, first-unconsumed fallback, explicit-id
    passthrough, multi-tool-result pairing, synth-on-no-parent, and
    no-cross-user-turn invariant.
  - test_openai_tool_passthrough.py: the two ChatMessage-level
    synth-on-missing tests are rewritten to assert that the per-
    message validator now leaves tool_call_id untouched; resolution
    coverage lives in the request-level tests above.

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

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

* studio: explicit tool_call_id reserve, numeric tmp-checkpoint suffix only

Reviewer follow-ups to the training-cleanup + tool_call_id walkback PR.

tool_call_id walkback: a mixed assistant turn with [call_a, call_b]
followed by a tool result that carried tool_call_id="call_a" and a
sibling tool result with no id resolved to ['call_a', 'call_a']
because the explicit id never reserved call_a in the consumed set.
Added a pre-pass over the message list that walks back from every
role="tool" message carrying an explicit id and marks the matching
(asst_idx, tc_idx) consumed, then the missing-id walkback runs against
that pre-populated set. The second result now resolves to call_b.

While here, also harden the function-shape check: if a provider
ships a malformed tool_call where `function` is a string rather than
a dict, the old `(tc.get("function") or {}).get("name")` raised
AttributeError on the string's .get; now isinstance-gated so the
walkback falls through to the fallback id without raising.

Cancel cleanup: `tmp-checkpoint-*` is too broad. HF Trainer's
in-flight partials are always `tmp-checkpoint-<integer-step>`, so
constrain the cleanup regex to `^tmp-checkpoint-\d+$`. A user folder
named `tmp-checkpoint-final`, `tmp-checkpoint-backup`, or
`tmp-checkpoint-user-notes` is now preserved.

ChatMessage docstring still pointed at the pre-PR contract that
required `tool_call_id` on every role="tool" message. Updated to say
missing ids are accepted at message scope and resolved at
ChatCompletionRequest scope. Inline comment above the cancel-cleanup
call now describes the actual behaviour (in-flight tmp partials,
completed checkpoints preserved).

Test:
  - python -m pytest studio/backend/tests/test_inference_model_validation.py
    studio/backend/tests/test_cleanup_cancelled_checkpoints.py
    studio/backend/tests/test_openai_tool_passthrough.py -q
    -> 76 passed (was 67 before this commit; +2 walkback regression
       tests, +1 numeric-suffix preservation test)

* studio: trim verbose comments in cleanup + tool_call_id walkback

Move the HF tmp-checkpoint regex to module scope as a named constant.
Drop the multi-paragraph docstring on _cleanup_cancelled_checkpoints
and the inline call-site rationale; the function name + the test
class already cover the why.

Compress _resolve_missing_tool_call_ids docstring from a six-line
explanation to two. Same logic, fewer in-flow tutorials.

76 tests in cleanup + inference-model-validation + tool-passthrough pass.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-05-18 00:01:48 -07:00

1015 lines
39 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 training job runs in a fresh subprocess (mp.get_context("spawn")),
solving the transformers version-switching problem. The old in-process
UnslothTrainer singleton is only used inside the subprocess (worker.py).
This file orchestrates the subprocess lifecycle, pumps events from the
worker's mp.Queue, and exposes the same API surface to routes/training.py.
Pattern follows core/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__)
_HF_TMP_CHECKPOINT_RE = re.compile(r"^tmp-checkpoint-\d+$")
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 and any non-numeric-suffix tmp dir
are user-owned and survive. Symlinked output_dir / children are skipped
so containment cannot 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 — kept here so the parent process
never needs to import the 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 training 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 was 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),
"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),
"random_seed": kwargs.get("random_seed", 3407),
"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"),
}
# Full finetuning always runs in 16-bit. LoRA/QLoRA and CPT preserve the
# explicit request so 4-bit adapter/raw-text runs remain possible.
if config["training_type"] == "Full Finetuning":
config["load_in_4bit"] = False
# Spawn subprocess — use 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 — safe because old pump thread is confirmed dead
# and 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 = {
k: v for k, v in config.items() if k not in {"hf_token", "wandb_token"}
}
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 the run appears in history during model loading
self._ensure_db_run_created()
# Start event pump thread
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 before returning
# (8s covers SQLite's default 5s lock timeout plus execution overhead)
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:
# Subprocess alive = active
if self._proc is not None and self._proc.is_alive():
return True
# Stop was requested and process exited → inactive
if self._should_stop:
return False
# Check progress state
p = self._progress
if p.is_training:
return True
if p.is_completed or p.error:
return False
# Check status message for activity indicators
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
# Try to read an event
event = self._read_queue(self._event_queue, timeout_sec = 0.25)
if event is not None:
self._handle_event(event)
continue
# No event — check if process is still alive
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 as 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 API endpoints are never 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 are sanitized below; update progress after coercion
_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
if _safe_loss is not None and not math.isfinite(_safe_loss):
_safe_loss = None
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
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 — reuse sanitized values from above
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 (loss/lr already sanitized above)
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"),
}
)
# Decide which DB action to take 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 []), "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 prevent unbounded 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 are preserved
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 (unchanged from original)
# ------------------------------------------------------------------
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.
With subprocess-based training, the model lives in the subprocess
and is freed when it exits. Inference must load from the saved
checkpoint on disk. This is a no-op placeholder.
"""
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