Files
YG_FT/compute/engines/llama_factory/inference.py
wuyongtao 0292bf5138 fix: 模型评测异步加载等待与多节点路由修复
- eval_runner 等待异步模型加载完成(InferenceSession.wait_until_loaded),
  修复 "model load failed: unknown"
- 评测算力节点选择:优先页面选择的节点 / 模型所在节点(_select_eval_node),
  多节点时不再派发到不可达节点导致连接超时
- 前端评测 GPU 选择改为节点感知(节点:GPU 复合值),透传 compute_node_id,
  并检查 startEval 结果展示真实错误
- 大模型评价(judge)使用模型记录的真实 API 模型名(api_model),
  避免用平台内部名调用 LLM API 导致 HTTP 400
- 新增后端节点选择与 compute wait_until_loaded 单元测试

Co-Authored-By: Claude <noreply@anthropic.com>
2026-08-04 18:21:16 +08:00

273 lines
11 KiB
Python

from __future__ import annotations
import threading
import time
import uuid
from typing import Any, Iterator
class InferenceSession:
"""Manages a loaded model for inference with LLaMA-Factory ChatModel.
Model loading is asynchronous: ``load()`` spawns a background daemon thread
and returns immediately with ``status == "loading"``. ``info()`` (served by
``/inference/status``) is always responsive, so the platform backend can
poll loading progress without being blocked by a minutes-long model load —
which previously froze the whole compute node event loop.
State machine: idle -> loading -> ready | error, ready -> idle (unload),
loading -> idle (cancelled). Long operations (ChatModel build, teardown,
generation) never run while holding ``_state_lock``; they either run in the
worker thread or under ``_chat_lock`` only.
"""
def __init__(self) -> None:
self._state_lock = threading.Lock() # brief state transitions only
self._chat_lock = threading.Lock() # serialize chat/teardown
self._status: str = "idle"
self._error: str = ""
self._request_id: str = ""
self._load_args: dict[str, Any] = {}
self._teardown_old = False # load-while-ready: unload old before loading new
self._cancel_requested = False # unload-while-loading: tear down after load finishes
self._load_thread: threading.Thread | None = None
self._model: Any = None
self._tokenizer: Any = None
self._generating_args: dict[str, Any] = {}
self._model_name: str = ""
self._adapter_path: str = ""
self._loaded_at: float = 0.0
@property
def status(self) -> str:
with self._state_lock:
return self._status
def info(self) -> dict[str, Any]:
with self._state_lock:
return {
"loaded": self._status == "ready",
"status": self._status,
"model_name": self._model_name,
"adapter_path": self._adapter_path,
"loaded_at": self._loaded_at,
"request_id": self._request_id,
"error": self._error,
}
def wait_until_loaded(self, timeout: float | None = None) -> dict[str, Any]:
"""Wait for an in-flight async load to finish and return its outcome.
供同步消费方(如 eval_runner 子进程)使用:``load()`` 立即返回 loading 后,
调用本方法等待后台加载线程完成,拿到最终的 loaded/error 结果。
若在 timeout 秒内仍未加载完成,返回 ``status == "loading"`` 并附上超时提示。
"""
with self._state_lock:
thread = self._load_thread
if thread is not None and thread.is_alive():
thread.join(timeout=timeout)
with self._state_lock:
loaded = self._status == "ready"
status = self._status
error = self._error
if not loaded and status == "loading":
error = error or f"model load timed out after {timeout or 'N/A'}s"
return {
"loaded": loaded,
"status": status,
"model_name": self._model_name,
"adapter_path": self._adapter_path,
"error": error,
}
def load(
self,
model_name_or_path,
adapter_name_or_path="",
template="qwen",
infer_backend="huggingface",
infer_dtype="auto",
**kwargs,
) -> dict[str, Any]:
with self._state_lock:
if self._status == "loading":
# A model is already loading — dedupe, reuse the same request id.
return {"loaded": False, "status": "loading", "request_id": self._request_id}
self._teardown_old = self._status == "ready"
self._status = "loading"
self._error = ""
self._request_id = uuid.uuid4().hex[:12]
self._cancel_requested = False
self._load_args = {
"model_name_or_path": model_name_or_path,
"template": template,
"infer_backend": infer_backend,
"infer_dtype": infer_dtype,
}
if adapter_name_or_path:
self._load_args["adapter_name_or_path"] = adapter_name_or_path
self._load_args.update(kwargs)
self._model_name = model_name_or_path
self._adapter_path = adapter_name_or_path
self._load_thread = threading.Thread(target=self._load_worker, daemon=True)
self._load_thread.start()
return {"loaded": False, "status": "loading", "request_id": self._request_id}
def _load_worker(self) -> None:
"""Build the ChatModel off the state lock so info() never blocks."""
model = None
tokenizer = None
generating_args: dict[str, Any] = {}
error = ""
try:
if self._teardown_old:
self._release_model()
from llamafactory.chat import ChatModel
from llamafactory.hparams import get_infer_args
args = dict(self._load_args)
infer_result = get_infer_args(args)
model = ChatModel(args)
tokenizer = getattr(model, "tokenizer", None) or model.engine.tokenizer
generating_args = infer_result[-1]
if hasattr(generating_args, "__dataclass_fields__"):
generating_args = {
k: v for k, v in vars(generating_args).items() if not k.startswith("_")
}
else:
generating_args = dict(generating_args)
except Exception as exc: # noqa: BLE001 - surface load failure via status
error = str(exc)
with self._state_lock:
if error:
self._model = None
self._tokenizer = None
self._status = "error"
self._error = error
return
if self._cancel_requested:
# Unload was requested while loading — drop the fresh model.
model = None
tokenizer = None
self._model = None
self._tokenizer = None
self._status = "idle"
return
self._model = model
self._tokenizer = tokenizer
self._generating_args = generating_args
self._loaded_at = time.time()
self._status = "ready"
def _release_model(self) -> None:
with self._chat_lock:
with self._state_lock:
self._status = "unloading"
model = self._model
self._model = None
self._tokenizer = None
if model is not None:
try:
del model
except Exception: # noqa: BLE001 - best-effort teardown
pass
# 强制释放 PyTorch CUDA 缓存,真正归还 GPU 显存
try:
import gc
gc.collect()
import torch
if torch.cuda.is_available():
torch.cuda.empty_cache()
torch.cuda.synchronize()
except Exception: # noqa: BLE001 - teardown must not raise
pass
with self._state_lock:
self._status = "idle"
self._model_name = ""
self._adapter_path = ""
self._loaded_at = 0.0
self._error = ""
def unload(self) -> dict[str, Any]:
with self._state_lock:
if self._status == "loading":
# Ask the worker to tear down right after the load finishes.
self._cancel_requested = True
return {"unloaded": False, "status": "cancelling", "request_id": self._request_id}
was_ready = self._status == "ready"
if was_ready:
self._release_model()
else:
with self._state_lock:
self._model = None
self._tokenizer = None
self._status = "idle"
self._model_name = ""
self._adapter_path = ""
self._loaded_at = 0.0
self._error = ""
return {"unloaded": True, "status": "idle"}
def chat(self, messages, temperature=0.95, top_p=0.7, max_new_tokens=1024, do_sample=True, **kwargs) -> dict[str, Any]:
with self._chat_lock:
with self._state_lock:
if self._status == "loading":
return {
"error": f"model is still loading (request_id={self._request_id}); please retry",
"response": "",
}
if self._status == "error":
return {"error": f"model load failed: {self._error}", "response": ""}
if self._status != "ready" or self._model is None:
return {"error": "model not loaded", "response": ""}
try:
generate_kwargs = {
"temperature": temperature,
"top_p": top_p,
"max_new_tokens": max_new_tokens,
"do_sample": do_sample,
}
generate_kwargs.update(kwargs)
system = next((m["content"] for m in messages if m["role"] == "system"), None)
user_messages = [m for m in messages if m["role"] != "system"]
responses = []
for response in self._model.stream_chat(user_messages, system=system, **generate_kwargs):
responses.append(response)
full_response = "".join(str(r) for r in responses)
return {"response": full_response}
except Exception as exc: # noqa: BLE001 - return generation error to caller
return {"error": str(exc), "response": ""}
def chat_stream(self, messages, **kwargs) -> Iterator[str]:
with self._chat_lock:
with self._state_lock:
if self._status == "loading":
yield 'data: {"error": "model is still loading; please retry"}\n\n'
return
if self._status == "error":
yield 'data: {"error": "model load failed: ' + str(self._error) + '"}\n\n'
return
if self._status != "ready" or self._model is None:
yield 'data: {"error": "model not loaded"}\n\n'
return
try:
generate_kwargs = {**kwargs}
system = next((m["content"] for m in messages if m["role"] == "system"), None)
user_messages = [m for m in messages if m["role"] != "system"]
for new_text in self._model.stream_chat(user_messages, system=system, **generate_kwargs):
yield new_text
except Exception as exc: # noqa: BLE001 - stream error as SSE event
yield 'data: {"error": "' + str(exc) + '"}\n\n'
_inference_session = None
def get_inference_session() -> InferenceSession:
global _inference_session
if _inference_session is None:
_inference_session = InferenceSession()
return _inference_session