unsloth/studio/backend/routes/training.py
Sanat Bhargava 1fc8bf53c7
Add Hugging Face dataset streaming mode to Studio (#4946)
* Add HF dataset streaming mode to Studio

* Added default value for datasetStreaming in training-config-store.ts

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

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

* Handle None max_steps for streaming validation

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

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

* studio: fast-fail streaming validation and guard incompatible modes

Reject dataset_streaming at the API boundary when hf_dataset is empty,
the dataset is vision/audio, or max_steps is not set. Probe eval split
with get_dataset_split_names before the streaming load so typos fail
immediately instead of mid-training. Guard column_names=None after map
on iterables. Hide the UI toggle for non-text configurations and clear
the stale flag when config becomes incompatible.

* studio: add streaming dataset tests, iterable helper, and streaming template/format support (WIP)

Work-in-progress on top of feat/studio-dataset-streaming-mode (PR #4946):
- new test_training_streaming.py and iterable.py dataset helper
- streaming support in chat_templates.py and format_conversion.py
- additional streaming guards in trainer.py / models / routes
- frontend streaming wiring in params-section and training-config-store

Committed to preserve uncommitted work before merging latest main.

* studio: fix review-team findings for streaming + main merge

BLOCKER: streaming + raw-text/CPT crashed on len(IterableDataset). Guard it in the
start route (reject format_type=="raw" or training_type=="Continued Pretraining")
and in isStreamingSupported (datasetFormat !== "raw").

Also:
- models/training.py: validate hf_dataset/subset/split (charset+length, block ..//);
  cap dataset slice indices (le=1e9); note validator ordering
- chat_templates.py: guard _apply_custom_mapping .map() for streaming
- trainer.py: warn when packing+streaming
- training-config-store.ts: persist-migration bump to v11 (standalone datasetStreaming
  backfill); add isVisionModel to NON_PERSISTED; toast on silent streamingCompatiblePatch
  mutations in the 4 indirect setters
- tests: route rejections (max_steps, raw/cpt), slice cap, unsafe hf_dataset

* studio: enable raw-text/CPT dataset streaming + streaming UX polish

- raw_text: keep the lazy filter but skip len()-based row counting for
  IterableDatasets so raw-text / CPT can stream; guard the eval-size log
- routes/trainer: drop the raw/CPT streaming block; add a defensive
  not-streaming guard on the eval auto-split (train_test_split)
- dataset-section: streaming toggle is visible-but-disabled and lists the
  exact unmet requirement(s) in its tooltip; block embedding models
- training-start-overlay: show "streaming (no full download)" instead of a
  stuck download bar for streaming runs
- trim the streaming test suite to the high-value cases

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

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

* studio: address streaming review (MLX/embedding guards, sliced eval split, rehydrate timing)

- routes: reject dataset_streaming for embedding training and on Apple Silicon
  (MLX); both loaders materialize the full dataset instead of streaming
- trainer: validate the base eval split name so streaming eval accepts HF slice
  syntax such as "validation[:1000]"
- training-config-store: defer the onRehydrateStorage setState to a microtask so
  it doesn't hit the store's TDZ during synchronous hydration
- test: streaming start rejects embedding models

* studio: harden HF dataset streaming (column_names, split slicing, empty/eval bounds, gating)

Address a deeper streaming review:
- raw_text: resolve_column_names() guards IterableDataset.column_names=None
  (from_generator / unresolved features) so raw-text and CPT streaming no longer
  raise TypeError before training
- models/routes: reject HF slice syntax in train_split/eval_split when streaming
  (load_dataset(streaming=True) raises "Bad split"); reject mixed sources
  (local/S3) and embedding/MLX streaming at the API, not just in the UI
- trainer: an empty post-slice/filter stream fails preflight with a clear message;
  streaming eval is capped (STREAMING_EVAL_MAX_SAMPLES) so each eval terminates;
  the manual-slice shortcut falls back to a regular load when train_split is sliced
- format_conversion: streaming conversions preflight the first mapped row so
  format errors surface before training, not mid-iteration
- frontend: block streaming on Apple Silicon; clear datasetStreaming when a
  dataset is detected as image/audio at start

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

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

* studio: fix CI for streaming PR (lint blocker + no-torch sandbox + preflight test)

- trainer.py: drop unused `IterableDataset` import (hoist safety-net blocker).
- test_training_streaming.py: only select real classes (isinstance type) when
  locating the trainer class, so a MagicMock-stubbed global is never passed to
  object.__new__ (fixes TypeError on the Python 3.10-3.13 jobs).
- no-torch import sandboxes (test_e2e_no_torch_sandbox.py,
  test_studio_import_no_torch.py): teach the chat_templates/format_conversion
  exec stubs and the full-import-chain copy list about the new `.iterable`
  module so the AFTER/runtime cases import without torch again.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Roland Tannous <115670425+rolandtannous@users.noreply.github.com>
Co-authored-by: Roland Tannous <rolandtannous@gravityq.ai>
Co-authored-by: Etherll <61019402+Etherll@users.noreply.github.com>
2026-06-22 17:48:18 +03:00

979 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 API routes
"""
import sys
from pathlib import Path
from fastapi import APIRouter, Depends, HTTPException, Request
from fastapi.responses import StreamingResponse
from typing import Dict, Optional, Any
import structlog
from loggers import get_logger
import asyncio
from datetime import datetime
import uuid as _uuid
# Add backend directory to path.
backend_path = Path(__file__).parent.parent.parent
if str(backend_path) not in sys.path:
sys.path.insert(0, str(backend_path))
try:
from core.training import get_training_backend
from core.training.resume import (
can_resume_run,
get_resume_checkpoint_path,
normalize_resume_output_dir,
)
from storage.studio_db import get_resumable_run_by_output_dir
from utils.models.model_config import load_model_defaults
from utils.paths import resolve_dataset_path
except ImportError:
# Fallback: parent directory.
parent_backend = backend_path.parent / "backend"
if str(parent_backend) not in sys.path:
sys.path.insert(0, str(parent_backend))
from core.training import get_training_backend
from core.training.resume import (
can_resume_run,
get_resume_checkpoint_path,
normalize_resume_output_dir,
)
from storage.studio_db import get_resumable_run_by_output_dir
from utils.models.model_config import load_model_defaults
from utils.paths import resolve_dataset_path
# Auth
from auth.authentication import get_current_subject
from utils.utils import log_and_http_error
from models import (
TrainingStartRequest,
TrainingJobResponse,
TrainingStatus,
TrainingProgress,
)
from models.responses import TrainingStopResponse, TrainingMetricsResponse
from pydantic import BaseModel as PydanticBaseModel
class TrainingStopRequest(PydanticBaseModel):
save: bool = True
router = APIRouter()
logger = get_logger(__name__)
def _validate_local_dataset_paths(paths: list[str], label: str = "Local dataset") -> list[str]:
"""Resolve and validate a list of local dataset paths. Returns validated absolute paths."""
validated = []
missing = []
for dataset_path in paths:
dataset_file = resolve_dataset_path(dataset_path)
if not dataset_file.exists():
missing.append(f"{dataset_path} (resolved: {dataset_file})")
continue
logger.info(f"Found {label.lower()} file: {dataset_file}")
validated.append(str(dataset_file))
if missing:
missing_detail = "; ".join(missing[:3])
raise HTTPException(
status_code = 400,
detail = f"{label} not found: {missing_detail}",
)
return validated
@router.get("/hardware")
async def get_hardware_utilization(current_subject: str = Depends(get_current_subject)):
"""
Live snapshot of GPU hardware utilization for the active backend.
Polled by the frontend during training.
"""
from utils.hardware import get_gpu_utilization
return get_gpu_utilization()
@router.get("/hardware/visible")
async def get_visible_hardware_utilization(current_subject: str = Depends(get_current_subject)):
from utils.hardware import get_visible_gpu_utilization
return get_visible_gpu_utilization()
@router.post("/start")
async def start_training(
request: TrainingStartRequest, current_subject: str = Depends(get_current_subject)
):
"""
Start a training job.
Initiates training in the background and returns immediately. Use /status
to check progress.
"""
try:
logger.info(f"Starting training job with model: {request.model_name}")
# No in-process ensure_transformers_version(): the subprocess
# (worker.py) activates the correct version before importing ML libs.
backend = get_training_backend()
# S3 dataset loading needs the optional boto3 dependency. Reject early
# with a clear message so credentials are never accepted and then
# silently dropped on a host without boto3 installed.
if request.s3_config is not None:
from core.training.s3_dataset import boto3_available
if not boto3_available():
raise HTTPException(
status_code = 501,
detail = "S3 dataset loading requires boto3. Install it with: pip install boto3",
)
# Check before mutating state.
if backend.is_training_active():
existing_job_id: Optional[str] = getattr(backend, "current_job_id", "")
return TrainingJobResponse(
job_id = existing_job_id or "",
status = "error",
message = (
"Training is already in progress. "
"Stop current training before starting a new one."
),
error = "Training already active",
)
# Job ID; start_training() sets it on the backend only after the old
# pump thread is dead.
job_id = f"job_{datetime.now().strftime('%Y%m%d_%H%M%S')}_{_uuid.uuid4().hex[:8]}"
# Validate dataset paths if provided.
if request.local_datasets:
request.local_datasets = _validate_local_dataset_paths(
request.local_datasets, "Local dataset"
)
if request.local_eval_datasets and request.eval_steps > 0:
request.local_eval_datasets = _validate_local_dataset_paths(
request.local_eval_datasets, "Local eval dataset"
)
resume_output_dir: Optional[str] = None
if request.resume_from_checkpoint:
try:
resume_output_dir = normalize_resume_output_dir(request.resume_from_checkpoint)
except ValueError as e:
# Deliberate user-facing validation message.
validation_message = str(e)
raise HTTPException(status_code = 400, detail = validation_message)
resume_run = get_resumable_run_by_output_dir(resume_output_dir)
if not resume_run or not can_resume_run(resume_run):
raise HTTPException(
status_code = 400,
detail = "Resume checkpoint must belong to a stopped run with saved trainer state.",
)
resume_checkpoint = get_resume_checkpoint_path(resume_output_dir)
if not resume_checkpoint:
raise HTTPException(
status_code = 400,
detail = "Resume checkpoint must include saved trainer state.",
)
request.resume_from_checkpoint = resume_checkpoint
# Validate streaming-mode compatibility before any expensive work.
# Streaming is supported only for Hugging Face text datasets.
if request.dataset_streaming:
if not request.hf_dataset:
raise HTTPException(
status_code = 400,
detail = "dataset_streaming requires hf_dataset; streaming is not supported for local datasets.",
)
if request.is_dataset_image or request.is_dataset_audio:
raise HTTPException(
status_code = 400,
detail = "dataset_streaming is not supported for vision or audio datasets.",
)
if request.is_embedding:
raise HTTPException(
status_code = 400,
detail = "dataset_streaming is not supported for embedding training; the embedding loader needs the full dataset.",
)
from utils.hardware import hardware as _hw
if _hw.DEVICE == _hw.DeviceType.MLX:
raise HTTPException(
status_code = 400,
detail = "dataset_streaming is not yet supported on Apple Silicon (MLX); the MLX loader materializes the full dataset.",
)
if request.max_steps is None or request.max_steps <= 0:
raise HTTPException(
status_code = 422,
detail = "dataset_streaming requires max_steps > 0 because streaming datasets have no known length.",
)
if request.train_on_completions:
raise HTTPException(
status_code = 422,
detail = "dataset_streaming is not supported with train_on_completions yet.",
)
if request.eval_steps > 0:
train_split = request.train_split or "train"
if not request.eval_split or request.eval_split == train_split:
raise HTTPException(
status_code = 422,
detail = "dataset_streaming with evaluation requires a separate eval_split.",
)
# Streaming is HF-only: reject when the request also carries a local
# dataset path or an S3 config; those sources cannot be streamed via
# HF's streaming loader.
if request.local_datasets:
raise HTTPException(
status_code = 400,
detail = (
"dataset_streaming is HF-only; remove local_datasets / S3 source. "
"Streaming is not supported with local file paths."
),
)
if request.s3_config is not None:
raise HTTPException(
status_code = 400,
detail = (
"dataset_streaming is HF-only; remove local_datasets / S3 source. "
"Streaming is not supported with S3 datasets."
),
)
# Convert request to backend kwargs.
training_kwargs = {
"model_name": request.model_name,
"training_type": request.training_type,
"hf_token": request.hf_token or "",
"load_in_4bit": request.load_in_4bit,
"max_seq_length": request.max_seq_length,
"vision_image_size": request.vision_image_size,
"hf_dataset": request.hf_dataset or "",
"local_datasets": request.local_datasets,
"local_eval_datasets": request.local_eval_datasets,
"format_type": request.format_type,
"subset": request.subset,
"train_split": request.train_split,
"dataset_streaming": request.dataset_streaming,
"eval_split": request.eval_split,
"eval_steps": request.eval_steps,
"dataset_slice_start": request.dataset_slice_start,
"dataset_slice_end": request.dataset_slice_end,
"custom_format_mapping": request.custom_format_mapping,
"num_epochs": request.num_epochs,
"learning_rate": request.learning_rate,
"embedding_learning_rate": request.embedding_learning_rate,
"batch_size": request.batch_size,
"gradient_accumulation_steps": request.gradient_accumulation_steps,
"warmup_steps": request.warmup_steps,
"warmup_ratio": request.warmup_ratio,
"max_steps": request.max_steps,
"save_steps": request.save_steps,
"weight_decay": request.weight_decay,
"max_grad_norm": request.max_grad_norm,
"max_grad_value": request.max_grad_value,
"max_grad_leaf_norm": request.max_grad_leaf_norm,
"cast_norm_output_to_input_dtype": request.cast_norm_output_to_input_dtype,
"random_seed": request.random_seed,
"packing": request.packing,
"optim": request.optim,
"lr_scheduler_type": request.lr_scheduler_type,
"use_lora": request.use_lora,
"lora_r": request.lora_r,
"lora_alpha": request.lora_alpha,
"lora_dropout": request.lora_dropout,
"target_modules": request.target_modules if request.target_modules else None,
"gradient_checkpointing": request.gradient_checkpointing.strip()
if request.gradient_checkpointing and request.gradient_checkpointing.strip()
else "unsloth",
"use_rslora": request.use_rslora,
"use_loftq": request.use_loftq,
"train_on_completions": request.train_on_completions,
"finetune_vision_layers": request.finetune_vision_layers,
"finetune_language_layers": request.finetune_language_layers,
"finetune_attention_modules": request.finetune_attention_modules,
"finetune_mlp_modules": request.finetune_mlp_modules,
"is_dataset_image": request.is_dataset_image,
"is_dataset_audio": request.is_dataset_audio,
"is_embedding": request.is_embedding,
"enable_wandb": request.enable_wandb,
"wandb_token": request.wandb_token or "",
"wandb_project": request.wandb_project or "",
"enable_tensorboard": request.enable_tensorboard,
"tensorboard_dir": request.tensorboard_dir or "",
"output_dir": resume_output_dir,
"resume_from_checkpoint": request.resume_from_checkpoint,
"trust_remote_code": request.trust_remote_code,
"approved_remote_code_fingerprint": request.approved_remote_code_fingerprint,
"subject": current_subject,
"gpu_ids": request.gpu_ids,
"s3_config": request.s3_config.model_dump() if request.s3_config else None,
}
# Training page has no trust_remote_code toggle, so honor the YAML default
# -- but only for genuine first-party (unsloth/nvidia) Hub repos, never a
# local path or a name merely starting with "unsloth/".
if not training_kwargs["trust_remote_code"]:
from utils.security.trusted_org import is_trusted_org_repo
model_defaults = load_model_defaults(request.model_name)
yaml_trust = model_defaults.get("training", {}).get("trust_remote_code", False)
if yaml_trust and is_trusted_org_repo(
request.model_name, hf_token = request.hf_token or None
):
logger.info(f"YAML config sets trust_remote_code=True for {request.model_name}")
training_kwargs["trust_remote_code"] = True
elif yaml_trust:
logger.warning(
"YAML sets trust_remote_code=True for %s but it is not a trusted "
"first-party repo; leaving disabled (user can opt in explicitly).",
request.model_name,
)
# Free VRAM for training: stop export, unload chat unless it can coexist.
# A before_spawn hook -> runs only after start_training's guards pass, so
# we never tear down chat/export VRAM for a start that is then refused.
def _free_vram_for_training() -> None:
try:
from core.export import get_export_backend
exp_backend = get_export_backend()
# Tear down the export subprocess whenever an export is in flight,
# not just once a checkpoint is loaded: during the load phase
# current_checkpoint is still unset while the worker is already
# allocating GPU memory, so gate on is_export_active() too.
if exp_backend.current_checkpoint or exp_backend.is_export_active():
logger.info("Shutting down export subprocess to free GPU memory for training")
exp_backend._shutdown_subprocess()
exp_backend.current_checkpoint = None
exp_backend.is_vision = False
exp_backend.is_peft = False
except Exception as e:
logger.warning("Could not shut down export subprocess: %s", e)
try:
from routes.training_vram import (
can_keep_chat_during_training,
free_chat_models_for_training,
summarize_resident_chat,
)
resident = summarize_resident_chat()
if not resident["any"]:
return
if resident.get("loading"):
# In-flight load can't be sized -> free rather than risk OOM.
freed = free_chat_models_for_training(reason = "chat model still loading")
logger.info("Freed in-flight chat load for training: %s", freed)
return
keep, info = can_keep_chat_during_training(
model_name = training_kwargs["model_name"],
hf_token = training_kwargs["hf_token"],
training_type = training_kwargs["training_type"],
load_in_4bit = training_kwargs["load_in_4bit"],
batch_size = training_kwargs["batch_size"],
max_seq_length = training_kwargs["max_seq_length"],
lora_rank = training_kwargs["lora_r"],
target_modules = training_kwargs["target_modules"],
gradient_checkpointing = training_kwargs["gradient_checkpointing"],
optimizer = training_kwargs["optim"],
gpu_ids = training_kwargs["gpu_ids"],
)
if keep:
logger.info(
"Keeping chat model(s) loaded during training "
"(free ~%s GB, needs ~%s GB): %s",
info.get("usable_gb"),
info.get("required_gb"),
resident,
)
else:
freed = free_chat_models_for_training(
reason = "insufficient VRAM to run training alongside chat",
)
logger.info("Freed chat model(s) for training: %s", freed)
except Exception as e:
logger.warning("Chat/training VRAM coordination failed; proceeding: %s", e)
# The hook runs only once start guards pass -> VRAM freed iff training starts.
success = backend.start_training(
job_id = job_id, before_spawn = _free_vram_for_training, **training_kwargs
)
if not success:
progress_error = backend.trainer.training_progress.error
return TrainingJobResponse(
job_id = backend.current_job_id or "",
status = "error",
message = progress_error or "Failed to start training subprocess",
error = progress_error or "subprocess_start_failed",
)
return TrainingJobResponse(
job_id = job_id,
status = "queued",
message = "Training job queued and starting in subprocess",
error = None,
)
except HTTPException:
# Deliberate rejections (S3 not implemented, resume validation) must
# reach the client with their original status, not a generic 500.
raise
except ValueError as e:
logger.warning("Rejected training GPU selection: %s", e)
# Deliberate user-facing GPU-selection validation message.
validation_message = str(e)
raise HTTPException(status_code = 400, detail = validation_message)
except Exception as e:
raise log_and_http_error(
e,
500,
"Failed to start training",
event = "training.start_failed",
log = logger,
)
@router.post("/stop", response_model = TrainingStopResponse)
async def stop_training(
body: TrainingStopRequest = TrainingStopRequest(),
current_subject: str = Depends(get_current_subject),
):
"""
Stop the currently running training job.
Body:
save (bool): If True (default), save the model at the current checkpoint.
"""
try:
backend = get_training_backend()
is_active = backend.is_training_active()
logger.info("Stop requested: save=%s is_active=%s", body.save, is_active)
if not is_active:
return TrainingStopResponse(
status = "idle", message = "No training job is currently running"
)
backend.stop_training(save = body.save)
return TrainingStopResponse(
status = "stopped",
message = "Stop requested. Training will stop at the next safe step.",
)
except Exception as e:
raise log_and_http_error(
e,
500,
"Failed to stop training",
event = "training.stop_failed",
log = logger,
)
@router.post("/reset")
async def reset_training(current_subject: str = Depends(get_current_subject)):
"""Reset training state so the user can return to configuration."""
try:
backend = get_training_backend()
is_active = backend.is_training_active()
if is_active:
if backend._cancel_requested:
# Cancel (save=False) requested — force-terminate to reset immediately.
logger.info("Force-terminating subprocess for immediate reset (cancel path)")
backend.force_terminate()
else:
logger.warning("Rejected reset while training active: is_active=%s", is_active)
raise HTTPException(
status_code = 409,
detail = "Training is still running. Stop training and wait for it to finish before resetting.",
)
logger.info("Reset training state: clearing runtime + metric history")
backend._should_stop = False # Clear stop flag so status returns to idle
backend.trainer._update_progress(
is_training = False,
is_completed = False,
error = None,
status_message = "Ready to train",
step = 0,
loss = None,
epoch = 0,
total_steps = 0,
)
backend.loss_history = []
backend.lr_history = []
backend.step_history = []
backend.grad_norm_history = []
backend.grad_norm_step_history = []
return {"status": "ok"}
except HTTPException:
raise
except Exception as e:
raise log_and_http_error(
e,
500,
"Failed to reset training",
event = "training.reset_failed",
log = logger,
)
@router.get("/status")
async def get_training_status(current_subject: str = Depends(get_current_subject)):
"""
Get the current training status.
"""
try:
backend = get_training_backend()
job_id: str = getattr(backend, "current_job_id", "") or ""
is_active = backend.is_training_active()
try:
progress = backend.trainer.get_training_progress()
except Exception:
progress = None
status_message = (
getattr(progress, "status_message", None) if progress else None
) or "Ready to train"
error_message = getattr(progress, "error", None) if progress else None
trainer_stopped = getattr(backend, "_should_stop", False)
# Derive high-level phase
if error_message:
phase = "error"
elif is_active:
msg_lower = status_message.lower()
if "loading" in msg_lower or "importing" in msg_lower:
phase = "loading_model"
elif any(k in msg_lower for k in ["preparing", "initializing", "configuring"]):
phase = "configuring"
else:
phase = "training"
elif trainer_stopped:
phase = "stopped"
elif progress and getattr(progress, "is_completed", False):
phase = "completed"
else:
phase = "idle"
details = None
if progress:
details = {
"epoch": getattr(progress, "epoch", 0),
"step": getattr(progress, "step", 0),
"total_steps": getattr(progress, "total_steps", 0),
"loss": getattr(progress, "loss", None),
"learning_rate": getattr(progress, "learning_rate", None),
}
output_dir = getattr(backend, "_output_dir", None)
if output_dir:
details["output_dir"] = output_dir
# Metric history for chart recovery after SSE reconnection.
metric_history = None
if backend.step_history:
metric_history = {
"steps": list(backend.step_history),
"loss": list(backend.loss_history),
"lr": list(backend.lr_history),
"grad_norm": list(getattr(backend, "grad_norm_history", [])),
"grad_norm_steps": list(getattr(backend, "grad_norm_step_history", [])),
"eval_loss": list(backend.eval_loss_history),
"eval_steps": list(backend.eval_step_history),
}
return TrainingStatus(
job_id = job_id,
phase = phase,
is_training_running = is_active,
eval_enabled = backend.eval_enabled,
message = status_message,
error = error_message,
details = details,
metric_history = metric_history,
)
except Exception as e:
raise log_and_http_error(
e,
500,
"Failed to get training status",
event = "training.status_failed",
log = logger,
)
@router.get("/metrics", response_model = TrainingMetricsResponse)
async def get_training_metrics(current_subject: str = Depends(get_current_subject)):
"""
Get training metrics (loss, learning rate, steps).
"""
try:
backend = get_training_backend()
loss_history = backend.loss_history
lr_history = backend.lr_history
step_history = backend.step_history
grad_norm_history = getattr(backend, "grad_norm_history", [])
grad_norm_step_history = getattr(backend, "grad_norm_step_history", [])
current_loss = loss_history[-1] if loss_history else None
current_lr = lr_history[-1] if lr_history else None
current_step = step_history[-1] if step_history else None
return TrainingMetricsResponse(
loss_history = loss_history,
lr_history = lr_history,
step_history = step_history,
grad_norm_history = grad_norm_history,
grad_norm_step_history = grad_norm_step_history,
current_loss = current_loss,
current_lr = current_lr,
current_step = current_step,
)
except Exception as e:
raise log_and_http_error(
e,
500,
"Failed to get training metrics",
event = "training.metrics_failed",
log = logger,
)
@router.get("/progress")
async def stream_training_progress(
request: Request, current_subject: str = Depends(get_current_subject)
):
"""
Stream training progress via Server-Sent Events (SSE).
Real-time progress with reconnection support per the SSE spec:
- `id:` per event so the browser tracks position.
- `retry:` to control reconnection interval.
- Named `event:` types (progress, heartbeat, complete, error).
- Reads `Last-Event-ID` on reconnect to replay missed steps.
"""
# Read Last-Event-ID header for reconnection resume.
last_event_id = request.headers.get("last-event-id")
resume_from_step: Optional[int] = None
if last_event_id is not None:
try:
resume_from_step = int(last_event_id)
logger.info(f"SSE reconnect: resuming from step {resume_from_step}")
except ValueError:
logger.warning(f"Invalid Last-Event-ID: {last_event_id}")
async def event_generator():
backend = get_training_backend()
job_id: str = getattr(backend, "current_job_id", "") or ""
# ── Helpers ──────────────────────────────────────────────
def build_progress(
step: int,
loss: Optional[float],
learning_rate: Optional[float],
total_steps: int,
epoch: Optional[float] = None,
progress: Optional[Any] = None,
grad_norm_override: Optional[float] = None,
eval_loss_override: Optional[float] = None,
) -> TrainingProgress:
total = max(total_steps, 0)
if step < 0 or total == 0:
progress_percent = 0.0
else:
progress_percent = float(step) / float(total) * 100.0 if total > 0 else 0.0
# Pull values from the progress object if available.
elapsed_seconds = getattr(progress, "elapsed_seconds", None) if progress else None
eta_seconds = getattr(progress, "eta_seconds", None) if progress else None
grad_norm = grad_norm_override
if grad_norm is None and progress:
grad_norm = getattr(progress, "grad_norm", None)
num_tokens = getattr(progress, "num_tokens", None) if progress else None
eval_loss = eval_loss_override
if eval_loss is None and progress:
eval_loss = getattr(progress, "eval_loss", None)
return TrainingProgress(
job_id = job_id,
step = step,
total_steps = total,
loss = loss,
learning_rate = learning_rate,
progress_percent = progress_percent,
epoch = epoch,
elapsed_seconds = elapsed_seconds,
eta_seconds = eta_seconds,
grad_norm = grad_norm,
num_tokens = num_tokens,
eval_loss = eval_loss,
)
def format_sse(
data: str,
event: str = "progress",
event_id: Optional[int] = None,
) -> str:
"""Format a single SSE message with id/event/data fields."""
lines = []
if event_id is not None:
lines.append(f"id: {event_id}")
lines.append(f"event: {event}")
lines.append(f"data: {data}")
lines.append("") # trailing blank line
lines.append("") # double newline terminates the event
return "\n".join(lines)
# ── Retry directive ──────────────────────────────────────
# Reconnect after 3 seconds if the connection drops.
yield "retry: 3000\n\n"
# ── Replay missed steps on reconnect ─────────────────────
if resume_from_step is not None and backend.step_history:
replayed = 0
grad_norm_by_step = {
step_val: grad_val
for step_val, grad_val in zip(
getattr(backend, "grad_norm_step_history", []),
getattr(backend, "grad_norm_history", []),
)
}
for i, step_val in enumerate(backend.step_history):
if step_val > resume_from_step:
loss_val = backend.loss_history[i] if i < len(backend.loss_history) else None
lr_val = backend.lr_history[i] if i < len(backend.lr_history) else None
tp_replay = getattr(
getattr(backend, "trainer", None), "training_progress", None
)
total_replay = (
getattr(tp_replay, "total_steps", step_val) if tp_replay else step_val
)
epoch_replay = getattr(tp_replay, "epoch", None) if tp_replay else None
payload = build_progress(
step_val,
loss_val,
lr_val,
total_replay,
epoch_replay,
progress = tp_replay,
grad_norm_override = grad_norm_by_step.get(step_val),
)
yield format_sse(payload.model_dump_json(), event = "progress", event_id = step_val)
replayed += 1
if replayed:
logger.info(f"SSE reconnect: replayed {replayed} missed steps")
# ── Initial status (only on fresh connections) ───────────
if resume_from_step is None:
is_active = backend.is_training_active()
tp = getattr(getattr(backend, "trainer", None), "training_progress", None)
initial_total_steps = getattr(tp, "total_steps", 0) if tp else 0
initial_epoch = getattr(tp, "epoch", None) if tp else None
initial_progress = build_progress(
step = 0,
loss = None,
learning_rate = None,
total_steps = initial_total_steps,
epoch = initial_epoch,
progress = tp,
)
yield format_sse(initial_progress.model_dump_json(), event = "progress", event_id = 0)
# If not active, send final state and exit
if not is_active:
_live = (getattr(tp, "step", 0) or 0) if tp else 0
if backend.step_history or _live > 0:
final_step = backend.step_history[-1] if backend.step_history else 0
final_loss = backend.loss_history[-1] if backend.loss_history else None
final_lr = backend.lr_history[-1] if backend.lr_history else None
# Histories skip non-finite steps; report the live step with
# loss=None instead of the last finite pair.
if _live > final_step:
final_step = _live
final_loss = getattr(tp, "loss", None)
final_lr = getattr(tp, "learning_rate", final_lr)
final_total_steps = getattr(tp, "total_steps", final_step) if tp else final_step
final_epoch = getattr(tp, "epoch", None) if tp else None
payload = build_progress(
final_step,
final_loss,
final_lr,
final_total_steps,
final_epoch,
progress = tp,
)
yield format_sse(
payload.model_dump_json(), event = "complete", event_id = final_step
)
else:
yield format_sse(
build_progress(-1, None, None, 0, progress = tp).model_dump_json(),
event = "complete",
event_id = 0,
)
return
# ── Live polling loop ────────────────────────────────────
last_step = resume_from_step if resume_from_step is not None else -1
no_update_count = 0
max_no_updates = 1800 # Timeout after 30 min (large models need compile time)
while backend.is_training_active():
try:
tp_inner = getattr(getattr(backend, "trainer", None), "training_progress", None)
live_step = (getattr(tp_inner, "step", 0) or 0) if tp_inner else 0
if backend.step_history or live_step > 0:
current_step = backend.step_history[-1] if backend.step_history else 0
current_loss = backend.loss_history[-1] if backend.loss_history else None
current_lr = backend.lr_history[-1] if backend.lr_history else None
# Histories skip non-finite steps; follow the live progress
# step and report its loss (None until it recovers).
if live_step > current_step:
current_step = live_step
current_loss = getattr(tp_inner, "loss", None)
current_lr = getattr(tp_inner, "learning_rate", current_lr)
current_total_steps = (
getattr(tp_inner, "total_steps", current_step) if tp_inner else current_step
)
current_epoch = getattr(tp_inner, "epoch", None) if tp_inner else None
# Only send if the step changed.
if current_step != last_step:
progress_payload = build_progress(
current_step,
current_loss,
current_lr,
current_total_steps,
current_epoch,
progress = tp_inner,
)
yield format_sse(
progress_payload.model_dump_json(),
event = "progress",
event_id = current_step,
)
last_step = current_step
no_update_count = 0
else:
no_update_count += 1
# Heartbeat every 10 seconds.
if no_update_count % 10 == 0:
heartbeat_payload = build_progress(
current_step,
current_loss,
current_lr,
current_total_steps,
current_epoch,
progress = tp_inner,
)
yield format_sse(
heartbeat_payload.model_dump_json(),
event = "heartbeat",
event_id = current_step,
)
else:
# No steps yet, but training is active (model loading, etc.).
no_update_count += 1
if no_update_count % 5 == 0:
# Pull total_steps + status so the frontend can show
# "Tokenizing…" etc.
tp_prep = getattr(
getattr(backend, "trainer", None),
"training_progress",
None,
)
prep_total = getattr(tp_prep, "total_steps", 0) if tp_prep else 0
preparing_payload = build_progress(
0,
None,
None,
prep_total,
progress = tp_prep,
)
yield format_sse(
preparing_payload.model_dump_json(),
event = "heartbeat",
event_id = 0,
)
# Timeout check
if no_update_count > max_no_updates:
logger.warning("Progress stream timeout - no updates received")
tp_timeout = getattr(
getattr(backend, "trainer", None), "training_progress", None
)
timeout_payload = build_progress(last_step, None, None, 0, progress = tp_timeout)
yield format_sse(
timeout_payload.model_dump_json(),
event = "error",
event_id = last_step if last_step >= 0 else 0,
)
break
await asyncio.sleep(1) # Poll every second
except Exception as e:
logger.error(f"Error in progress stream: {e}", exc_info = True)
tp_error = getattr(getattr(backend, "trainer", None), "training_progress", None)
error_payload = build_progress(0, None, None, 0, progress = tp_error)
yield format_sse(
error_payload.model_dump_json(),
event = "error",
event_id = last_step if last_step >= 0 else 0,
)
break
# ── Final "complete" event ───────────────────────────────
final_step = backend.step_history[-1] if backend.step_history else last_step
final_loss = backend.loss_history[-1] if backend.loss_history else None
final_lr = backend.lr_history[-1] if backend.lr_history else None
final_tp = getattr(getattr(backend, "trainer", None), "training_progress", None)
# If the run ended on a non-finite stretch, report the live step with
# loss=None instead of rolling back to the last finite pair.
_final_live_step = (getattr(final_tp, "step", 0) or 0) if final_tp else 0
if _final_live_step > (final_step if final_step is not None else -1):
final_step = _final_live_step
final_loss = getattr(final_tp, "loss", None)
final_lr = getattr(final_tp, "learning_rate", final_lr)
final_total_steps = getattr(final_tp, "total_steps", final_step) if final_tp else final_step
final_epoch = getattr(final_tp, "epoch", None) if final_tp else None
final_payload = build_progress(
final_step,
final_loss,
final_lr,
final_total_steps,
final_epoch,
progress = final_tp,
)
yield format_sse(
final_payload.model_dump_json(),
event = "complete",
event_id = final_step if final_step >= 0 else 0,
)
return StreamingResponse(
event_generator(),
media_type = "text/event-stream",
headers = {
"Cache-Control": "no-cache",
"Connection": "keep-alive",
"X-Accel-Buffering": "no",
},
)