xsl
3350e0ad77
- 全局槽换为 _PrioritySemaphore：priority 大者排到等待队列最前，同级 FIFO， 无等待者时才允许直接获取（收紧 asyncio.Semaphore 的 barging）； 授予槽位瞬间请求被取消时归还槽位，防泄漏 - worker 池 Condition FIFO 等待改为显式优先级等待队列，release 唤醒队首； 被唤醒但 worker 被抢时按原序号重排；授予/取消竞态时转手唤醒下一位 - forward.py 新增 PRIORITY_PATHS（现仅接口5 /api/v1/hairline/generate） - 新增 4 个单测：两级队列的插队 + 同级 FIFO
462 lines
18 KiB
Python
462 lines
18 KiB
Python
"""Worker 健康池 + 空闲派发。
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- 后台 asyncio 任务周期性探测每个 worker 的 /health
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- 连续失败 N 次 → 下线；连续成功 N 次 → 上线
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- 每个 worker 一个 busy 标志（per_worker_concurrency=1）
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- acquire_worker() 从在线池挑空闲 worker；全忙排队；池空→NoWorkerAvailable
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- release_worker() 释放 worker
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- 两级排队（全局槽 / worker 池）均支持优先级：priority 大者插到队列最前，
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同优先级 FIFO；已有等待者时新请求不得越过（严格按优先级排序）
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"""
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import asyncio
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import logging
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import time
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from dataclasses import dataclass, field
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from typing import Dict, List, Optional
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import httpx
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logger = logging.getLogger("gateway.pool")
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def _cooldown_seconds() -> float:
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"""被动摘除后的隔离期时长（秒），配置 health_check.cooldown_seconds，默认 60。"""
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try:
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from gateway.config import get_config
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return float(get_config()["health_check"].get("cooldown_seconds", 60))
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except Exception: # noqa: BLE001
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return 60.0
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# ---------------------------------------------------------------------------
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# 异常
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# ---------------------------------------------------------------------------
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class NoWorkerAvailable(Exception):
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"""无可用 worker（池空或全忙排队超时）。"""
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pass
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# ---------------------------------------------------------------------------
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# 数据结构
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# ---------------------------------------------------------------------------
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@dataclass
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class WorkerState:
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"""单个 worker 的运行时状态。"""
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url: str
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online: bool = False # 初始 offline，等健康检查通过后上线
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busy: bool = False
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primary: bool = True # 主 worker（True 优先派发）；全部主 worker 下线才用备组
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consecutive_failures: int = 0
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consecutive_successes: int = 0
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offline_until: float = 0.0 # 被动摘除后的隔离截止时刻（time.monotonic() 基准）
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# ---------------------------------------------------------------------------
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# 全局状态
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# ---------------------------------------------------------------------------
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_workers: Dict[str, WorkerState] = {}
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_pool_condition: Optional[asyncio.Condition] = None
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_health_task: Optional[asyncio.Task] = None
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_shutdown_event: Optional[asyncio.Event] = None
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# worker 池等待者：[(-priority, 入队序号, future)]，按 (-priority, 序号) 升序排列。
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# 等待者在持有 _pool_condition 锁时增删；release_worker() 唤醒队首（优先级最高者）。
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_worker_waiters: List[tuple] = []
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_waiter_seq: int = 0
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# 全局串行槽：同一时间最多 max_global_concurrency 个请求进入 worker 派发，其余排队。
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# ⚠️ 依赖单进程 uvicorn 部署（hair-gateway.service 无 --workers）。
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# 若改多 worker / gunicorn，进程内信号量会失效，需换成跨进程锁（文件锁/Redis）。
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_global_sem: Optional["_PrioritySemaphore"] = None
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_global_max: int = 1
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_global_busy: int = 0
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_global_waiting: int = 0
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# ---------------------------------------------------------------------------
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# 优先级信号量
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# ---------------------------------------------------------------------------
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class _PrioritySemaphore:
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"""带插队优先级的信号量（替代 asyncio.Semaphore，后者不支持优先级）。
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等待者按 (-priority, 入队序号) 排序：priority 大者先获得槽位（插队到最前），
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同优先级 FIFO。仅当无等待者时才允许直接获取——防止新请求越过排队者
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（asyncio.Semaphore 本身允许这种插队，这里收紧以保证优先级语义）。
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"""
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def __init__(self, value: int) -> None:
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self._value = value
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self._waiters: List[tuple] = [] # [(-priority, seq, future)]
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self._seq = 0
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async def acquire(self, priority: int = 0) -> None:
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if self._value > 0 and not self._waiters:
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self._value -= 1
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return
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loop = asyncio.get_running_loop()
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fut = loop.create_future()
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self._seq += 1
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entry = (-priority, self._seq, fut)
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idx = 0
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while idx < len(self._waiters) and self._waiters[idx][:2] <= entry[:2]:
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idx += 1
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self._waiters.insert(idx, entry)
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if priority > 0 and idx < len(self._waiters) - 1:
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logger.info("优先级请求插队到全局队列第 %d 位（超越 %d 个等待者）",
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idx + 1, len(self._waiters) - 1 - idx)
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try:
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await fut
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except asyncio.CancelledError:
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if fut.done() and not fut.cancelled():
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# 已被 release 授予槽位、但本任务随后被取消 → 归还槽位
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self.release()
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else:
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try:
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self._waiters.remove(entry)
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except ValueError:
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pass
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raise
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def release(self) -> None:
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while self._waiters:
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_, _, fut = self._waiters.pop(0)
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if not fut.done():
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fut.set_result(None)
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return
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self._value += 1
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# ---------------------------------------------------------------------------
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# 健康检查后台任务
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# ---------------------------------------------------------------------------
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def _try_revive(w: WorkerState, healthy_threshold: int) -> bool:
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"""探测成功后是否允许将该 worker 复活上线。
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条件：未在线 + 连续成功达到阈值 + **不在被动摘除隔离期内**
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（offline_until 之前即使 /health 探测成功也压着不上线，防横跳）。
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"""
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if w.online or w.consecutive_successes < healthy_threshold:
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return False
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if time.monotonic() < w.offline_until:
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logger.debug("Worker %s 探测成功但处于隔离期，暂不复活", w.url)
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return False
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return True
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async def _health_check_loop(cfg: dict) -> None:
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"""后台循环：周期性探测所有 worker 健康状态。"""
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hc_cfg = cfg["health_check"]
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interval = hc_cfg["interval_seconds"]
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unhealthy_threshold = hc_cfg["unhealthy_threshold"]
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healthy_threshold = hc_cfg["healthy_threshold"]
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token = cfg["shared_password"]
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logger.info(
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"健康检查循环启动 | 间隔=%ds | 下线阈值=%d | 上线阈值=%d | 隔离期=%.0fs | workers=%d",
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interval, unhealthy_threshold, healthy_threshold, _cooldown_seconds(), len(_workers),
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)
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async with httpx.AsyncClient() as client:
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while not _shutdown_event.is_set():
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for w in _workers.values():
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url = f"{w.url}{hc_cfg['path']}"
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try:
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resp = await client.get(
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url,
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headers={"X-Internal-Token": token},
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timeout=hc_cfg["timeout_seconds"],
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)
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if resp.status_code == 200:
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w.consecutive_failures = 0
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w.consecutive_successes += 1
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if _try_revive(w, healthy_threshold):
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w.online = True
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logger.info("✅ Worker 上线: %s", w.url)
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else:
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w.consecutive_successes = 0
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w.consecutive_failures += 1
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if w.consecutive_failures >= unhealthy_threshold and w.online:
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w.online = False
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logger.warning("⚠ Worker 下线: %s（HTTP %d，连续失败 %d 次）",
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w.url, resp.status_code, w.consecutive_failures)
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except Exception as exc:
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w.consecutive_successes = 0
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w.consecutive_failures += 1
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if w.consecutive_failures >= unhealthy_threshold and w.online:
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w.online = False
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logger.warning("⚠ Worker 下线: %s（%s，连续失败 %d 次）",
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w.url, exc, w.consecutive_failures)
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# 等待下一次探测（支持快速关闭）
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try:
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await asyncio.wait_for(_shutdown_event.wait(), timeout=interval)
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break # shutdown signaled
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except asyncio.TimeoutError:
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pass # 正常的 interval 到期
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logger.info("健康检查循环已停止")
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# ---------------------------------------------------------------------------
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# 初始化 / 关闭
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# ---------------------------------------------------------------------------
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async def init_pool(cfg: dict) -> None:
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"""初始化 worker 池并启动健康检查后台任务。"""
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global _workers, _pool_condition, _health_task, _shutdown_event
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# 主 worker 分组：配置了 primary_workers 则按其标记，否则全部视为主 worker
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primary_set = set(cfg.get("primary_workers") or cfg["workers"])
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_workers = {url: WorkerState(url=url, primary=url in primary_set)
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for url in cfg["workers"]}
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n_primary = sum(1 for w in _workers.values() if w.primary)
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_pool_condition = asyncio.Condition()
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_shutdown_event = asyncio.Event()
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# 全局串行槽（独立于 worker busy 标志）
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init_global_slot(cfg)
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# 立即做一轮健康检查以快速上线
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hc_cfg = cfg["health_check"]
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token = cfg["shared_password"]
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async with httpx.AsyncClient() as client:
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for w in _workers.values():
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try:
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resp = await client.get(
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f"{w.url}{hc_cfg['path']}",
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headers={"X-Internal-Token": token},
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timeout=hc_cfg["timeout_seconds"],
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)
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if resp.status_code == 200:
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w.consecutive_successes = 1
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if hc_cfg["healthy_threshold"] <= 1:
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w.online = True
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else:
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w.consecutive_failures = 1
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except Exception:
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w.consecutive_failures = 1
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# 对于 healthy_threshold == 1 的情况，已在上面的检查中上线
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# 标记初始在线状态
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online_count = sum(1 for w in _workers.values() if w.online)
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logger.info("Worker 池初始化完成 | 总数=%d | 在线=%d | 主worker=%d",
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len(_workers), online_count, n_primary)
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# 启动后台健康检查
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_health_task = asyncio.create_task(_health_check_loop(cfg))
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async def shutdown_pool() -> None:
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"""关闭健康检查任务，释放资源。"""
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global _shutdown_event, _health_task
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if _shutdown_event:
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_shutdown_event.set()
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if _health_task:
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_health_task.cancel()
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try:
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await _health_task
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except asyncio.CancelledError:
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pass
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_health_task = None
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logger.info("Worker 池已关闭")
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# ---------------------------------------------------------------------------
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# 全局串行槽
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# ---------------------------------------------------------------------------
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def init_global_slot(cfg: dict) -> None:
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"""初始化全局串行信号量。
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max_global_concurrency=N → 同一时间最多 N 个请求进入 worker 派发，其余排队。
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priority>0 的请求可插队到等待队列最前（见 _PrioritySemaphore）。
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依赖单进程 uvicorn 部署；多进程需换跨进程锁。
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"""
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global _global_sem, _global_max, _global_busy, _global_waiting
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n = int(cfg.get("dispatch", {}).get("max_global_concurrency", 1))
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if n < 1:
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n = 1
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_global_sem = _PrioritySemaphore(n)
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_global_max = n
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_global_busy = 0
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_global_waiting = 0
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logger.info("全局并发槽初始化: max=%d（单进程生效）", n)
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async def acquire_global_slot(cfg: dict, priority: int = 0) -> bool:
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"""获取一个全局处理槽。True=获得；False=排队超时。
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priority>0 的请求插队到等待队列最前，同优先级 FIFO。
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超时由 dispatch.max_queue_wait_seconds 控制（需 < nginx proxy_read_timeout 600s）。
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"""
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global _global_busy, _global_waiting
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if _global_sem is None:
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return True # 未初始化，不限流
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timeout = float(cfg.get("dispatch", {}).get("max_queue_wait_seconds", 590))
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_global_waiting += 1
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try:
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await asyncio.wait_for(_global_sem.acquire(priority), timeout=timeout)
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_global_busy += 1
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return True
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except asyncio.TimeoutError:
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logger.warning("全局排队超时（%.1fs），拒绝请求 | waiting=%d", timeout, _global_waiting)
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return False
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finally:
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_global_waiting -= 1
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def release_global_slot() -> None:
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"""释放全局处理槽。"""
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global _global_busy
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if _global_sem is not None:
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_global_busy -= 1
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_global_sem.release()
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# ---------------------------------------------------------------------------
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# 派发
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# ---------------------------------------------------------------------------
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async def mark_worker_unhealthy(w: WorkerState) -> None:
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"""被动标记：转发失败时立即将该 worker 下线，并进入隔离期。
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隔离期内即使 /health 探测成功也不复活（由 _try_revive 守卫），
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避免"摘除→8 秒复活→再失败"的横跳。
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"""
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async with _pool_condition:
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if w.online:
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w.online = False
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w.consecutive_failures += 1
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cooldown = _cooldown_seconds()
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w.offline_until = time.monotonic() + cooldown
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logger.warning("⚠ Worker 被动下线: %s（转发失败，隔离 %.0fs）",
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w.url, cooldown)
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def _insert_worker_waiter(key: tuple, fut: asyncio.Future) -> tuple:
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"""按 (-priority, 序号) 升序插入等待者（须在持有 _pool_condition 锁时调用）。"""
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entry = (key[0], key[1], fut)
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idx = 0
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while idx < len(_worker_waiters) and _worker_waiters[idx][:2] <= entry[:2]:
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idx += 1
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_worker_waiters.insert(idx, entry)
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return entry
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def _wake_best_worker_waiter() -> None:
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"""唤醒优先级最高的等待者（须在持有 _pool_condition 锁时调用）。"""
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while _worker_waiters:
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_, _, fut = _worker_waiters.pop(0)
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if not fut.done():
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fut.set_result(None)
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return
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async def acquire_worker(cfg: dict, priority: int = 0) -> WorkerState:
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"""从在线池中获取一个空闲 worker。
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主备分组：只要还有主 worker（primary）在线，就只在主组内挑空闲
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（全忙则排队等待，不用备组）；只有主组全部下线时才用备用 worker。
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全忙则排队等待，最多 queue_wait_seconds；池空立即抛异常。
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排队按 (-priority, 入队序号) 排序：priority 大者插队到最前，同优先级 FIFO；
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已有等待者时新请求不得越过（保证优先级语义，防饿死）。
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"""
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queue_wait = cfg["dispatch"]["queue_wait_seconds"]
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deadline = time.monotonic() + queue_wait
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my_key: Optional[tuple] = None # (-priority, seq)，被唤醒后重排仍用原序号
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woken = False # 是否刚被 release_worker 唤醒（被唤醒者直接参与挑选）
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while True:
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async with _pool_condition:
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online = [w for w in _workers.values() if w.online]
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primary_online = [w for w in online if w.primary]
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# 主组有在线 → 只在主组内挑；主组全挂 → 才轮到备组
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candidates = primary_online if primary_online else online
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idle = [w for w in candidates if not w.busy]
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if idle and (woken or not _worker_waiters):
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# 取第一个空闲 worker
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w = idle[0]
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w.busy = True
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if not w.primary:
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logger.info("主 worker 全部下线，使用备用 worker: %s", w.url)
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logger.debug("Worker 分配: %s", w.url)
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return w
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if not online:
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raise NoWorkerAvailable("后端服务暂不可用，请稍后重试")
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remaining = deadline - time.monotonic()
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if remaining <= 0:
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raise NoWorkerAvailable("后端服务繁忙，请稍后重试")
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if my_key is None:
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global _waiter_seq
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_waiter_seq += 1
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my_key = (-priority, _waiter_seq)
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first_enqueue = True
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else:
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first_enqueue = False
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fut = asyncio.get_running_loop().create_future()
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entry = _insert_worker_waiter(my_key, fut)
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if first_enqueue:
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pos = _worker_waiters.index(entry) + 1
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if not idle:
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logger.info("所有可用 worker 全忙（%d 在线），等待 %.1fs...",
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len(candidates), remaining)
|
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if priority > 0 and pos < len(_worker_waiters):
|
||
logger.info("优先级请求插队到 worker 队列第 %d 位（超越 %d 个等待者）",
|
||
pos, len(_worker_waiters) - pos)
|
||
|
||
try:
|
||
await asyncio.wait_for(fut, timeout=remaining)
|
||
woken = True
|
||
except asyncio.TimeoutError:
|
||
async with _pool_condition:
|
||
try:
|
||
_worker_waiters.remove(entry)
|
||
except ValueError:
|
||
# 授予与取消竞态：已被弹出授予（worker 空闲），转手唤醒下一位
|
||
if fut.done() and not fut.cancelled():
|
||
_wake_best_worker_waiter()
|
||
raise NoWorkerAvailable("后端服务繁忙，请稍后重试")
|
||
|
||
|
||
async def release_worker(w: WorkerState) -> None:
|
||
"""释放 worker，标记为空闲并唤醒优先级最高的等待者。"""
|
||
async with _pool_condition:
|
||
w.busy = False
|
||
logger.debug("Worker 释放: %s", w.url)
|
||
_wake_best_worker_waiter()
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# 状态查询
|
||
# ---------------------------------------------------------------------------
|
||
|
||
def get_pool_status() -> dict:
|
||
"""返回当前池状态（供 /gateway-health 使用）。"""
|
||
global_info = {
|
||
"global_max": _global_max,
|
||
"global_busy": _global_busy,
|
||
"global_waiting": _global_waiting,
|
||
}
|
||
if not _workers:
|
||
return {"total": 0, "healthy": 0, "busy": 0,
|
||
"primary_total": 0, "primary_healthy": 0, **global_info}
|
||
total = len(_workers)
|
||
healthy = sum(1 for w in _workers.values() if w.online)
|
||
busy = sum(1 for w in _workers.values() if w.busy)
|
||
primary_total = sum(1 for w in _workers.values() if w.primary)
|
||
primary_healthy = sum(1 for w in _workers.values() if w.primary and w.online)
|
||
return {"total": total, "healthy": healthy, "busy": busy,
|
||
"primary_total": primary_total, "primary_healthy": primary_healthy,
|
||
**global_info}
|