perf: 启动预热优化 - 解决容器重启后首批任务慢/失败

问题：容器重启后前两批任务明显变慢或失败
- 第一批：代理/目标服务器连接冷启动导致超时
- 第二批：浏览器池冷启动需要创建浏览器

解决方案：
- browser_pool_worker.py: 添加 pre_warm 参数，启动时预创建1个浏览器
- api_browser.py: 添加 warmup_api_connection() 预热 TCP/TLS 连接
- api_browser.py: 首次请求使用更长超时(10s)，后续恢复正常
- app.py: 启动时后台调用 API 预热

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

api_browser.py

@@ -71,6 +71,7 @@ class APIBrowser:
         self.log_callback = log_callback
         self.stop_flag = False
         self._closed = False  # 防止重复关闭
+        self._first_request = True
         self.last_total_records = 0
 
         # 设置代理
@@ -132,7 +133,12 @@ class APIBrowser:
 
     def _request_with_retry(self, method, url, max_retries=3, retry_delay=1, **kwargs):
         """带重试机制的请求方法"""
-        kwargs.setdefault('timeout', _API_REQUEST_TIMEOUT_SECONDS)
+        # 首次请求使用更长超时（10秒），后续使用配置的超时
+        if self._first_request:
+            kwargs.setdefault('timeout', 10.0)
+            self._first_request = False
+        else:
+            kwargs.setdefault('timeout', _API_REQUEST_TIMEOUT_SECONDS)
         last_error = None
         
         for attempt in range(1, max_retries + 1):
@@ -518,3 +524,28 @@ class APIBrowser:
         """Context manager支持 - 退出"""
         self.close()
         return False  # 不抑制异常
+
+
+def warmup_api_connection(proxy_config: Optional[dict] = None, log_callback: Optional[Callable] = None):
+    """预热 API 连接 - 建立 TCP/TLS 连接池"""
+
+    def log(msg: str):
+        if log_callback:
+            log_callback(msg)
+        else:
+            print(f"[API预热] {msg}")
+
+    log("正在预热 API 连接...")
+    try:
+        session = requests.Session()
+        if proxy_config and proxy_config.get("server"):
+            session.proxies = {"http": proxy_config["server"], "https": proxy_config["server"]}
+
+        # 发送一个轻量级请求建立连接
+        resp = session.get(f"{BASE_URL}/admin/login.aspx", timeout=10, allow_redirects=False)
+        log(f"✓ API 连接预热完成 (status={resp.status_code})")
+        session.close()
+        return True
+    except Exception as e:
+        log(f"API 连接预热失败: {e}")
+        return False

app.py

@@ -277,6 +277,21 @@ if __name__ == "__main__":
     except Exception as e:
         logger.warning(f"警告: 截图线程池初始化失败: {e}")
 
+    # 预热 API 连接（后台进行，不阻塞启动）
+    logger.info("预热 API 连接...")
+    try:
+        from api_browser import warmup_api_connection
+        import threading
+
+        threading.Thread(
+            target=warmup_api_connection,
+            kwargs={"log_callback": lambda msg: logger.info(msg)},
+            daemon=True,
+            name="api-warmup",
+        ).start()
+    except Exception as e:
+        logger.warning(f"API 预热失败: {e}")
+
     socketio.run(
         app,
         host=config.SERVER_HOST,

browser_pool_worker.py

@@ -38,7 +38,13 @@ BROWSER_MAX_USE_COUNT = int(os.environ.get('BROWSER_MAX_USE_COUNT', '0'))  # 每
 class BrowserWorker(threading.Thread):
     """浏览器工作线程 - 每个worker维护自己的浏览器"""
 
-    def __init__(self, worker_id: int, task_queue: queue.Queue, log_callback: Optional[Callable] = None):
+    def __init__(
+        self,
+        worker_id: int,
+        task_queue: queue.Queue,
+        log_callback: Optional[Callable] = None,
+        pre_warm: bool = False,
+    ):
         super().__init__(daemon=True)
         self.worker_id = worker_id
         self.task_queue = task_queue
@@ -48,6 +54,7 @@ class BrowserWorker(threading.Thread):
         self.idle = True
         self.total_tasks = 0
         self.failed_tasks = 0
+        self.pre_warm = pre_warm
 
     def log(self, message: str):
         """日志输出"""
@@ -124,19 +131,33 @@ class BrowserWorker(threading.Thread):
 
     def run(self):
         """工作线程主循环 - 按需启动浏览器模式"""
-        self.log("Worker启动（按需模式，等待任务时不占用浏览器资源）")
+        if self.pre_warm:
-        last_task_time = 0
+            self.log("Worker启动（预热模式，启动即创建浏览器）")
+        else:
+            self.log("Worker启动（按需模式，等待任务时不占用浏览器资源）")
+
+        last_activity_time = 0
+        if self.pre_warm and not self.browser_instance:
+            if self._create_browser():
+                last_activity_time = time.time()
+            self.pre_warm = False
 
         while self.running:
             try:
+                # 允许运行中触发预热（例如池在初始化后调用 warmup）
+                if self.pre_warm and not self.browser_instance:
+                    if self._create_browser():
+                        last_activity_time = time.time()
+                    self.pre_warm = False
+
                 # 从队列获取任务（带超时，以便能响应停止信号和空闲检查）
                 self.idle = True
                 try:
                     task = self.task_queue.get(timeout=TASK_QUEUE_TIMEOUT)
                 except queue.Empty:
                     # 检查是否需要关闭空闲的浏览器
-                    if self.browser_instance and last_task_time > 0:
+                    if self.browser_instance and last_activity_time > 0:
-                        idle_time = time.time() - last_task_time
+                        idle_time = time.time() - last_activity_time
                         if idle_time > BROWSER_IDLE_TIMEOUT:
                             self.log(f"空闲{int(idle_time)}秒，关闭浏览器释放资源")
                             self._close_browser()
@@ -171,13 +192,13 @@ class BrowserWorker(threading.Thread):
                     result = task_func(self.browser_instance, *task_args, **task_kwargs)
                     callback(result, None)
                     self.log(f"任务执行成功")
-                    last_task_time = time.time()
+                    last_activity_time = time.time()
 
                 except Exception as e:
                     self.log(f"任务执行失败: {e}")
                     callback(None, str(e))
                     self.failed_tasks += 1
-                    last_task_time = time.time()
+                    last_activity_time = time.time()
 
                     # 任务失败后，检查浏览器健康
                     if not self._check_browser_health():
@@ -223,7 +244,7 @@ class BrowserWorkerPool:
             print(f"[浏览器池] {message}")
 
     def initialize(self):
-        """初始化工作线程池（按需模式，启动时不创建浏览器）"""
+        """初始化工作线程池（按需模式，默认预热1个浏览器）"""
         with self.lock:
             if self.initialized:
                 return
@@ -236,7 +257,8 @@ class BrowserWorkerPool:
                 worker = BrowserWorker(
                     worker_id=i + 1,
                     task_queue=self.task_queue,
-                    log_callback=self.log_callback
+                    log_callback=self.log_callback,
+                    pre_warm=(i < 1),
                 )
                 worker.start()
                 self.workers.append(worker)
@@ -244,6 +266,39 @@ class BrowserWorkerPool:
             self.initialized = True
             self.log(f"✓ 工作线程池初始化完成（{self.pool_size}个worker就绪，浏览器将在有任务时按需启动）")
 
+        # 初始化完成后，默认预热1个浏览器，降低容器重启后前几批任务的冷启动开销
+        self.warmup(1)
+
+    def warmup(self, count: int = 1) -> int:
+        """预热浏览器池 - 预创建指定数量的浏览器"""
+        if count <= 0:
+            return 0
+
+        if not self.initialized:
+            self.log("警告：线程池未初始化，无法预热")
+            return 0
+
+        with self.lock:
+            target_workers = list(self.workers[: min(count, len(self.workers))])
+
+        self.log(f"预热浏览器池（预创建{len(target_workers)}个浏览器）...")
+
+        for worker in target_workers:
+            if not worker.browser_instance:
+                worker.pre_warm = True
+
+        # 等待预热完成（最多等待20秒，避免阻塞过久）
+        deadline = time.time() + 20
+        while time.time() < deadline:
+            warmed = sum(1 for w in target_workers if w.browser_instance)
+            if warmed >= len(target_workers):
+                break
+            time.sleep(0.1)
+
+        warmed = sum(1 for w in target_workers if w.browser_instance)
+        self.log(f"✓ 浏览器池预热完成（{warmed}个浏览器就绪）")
+        return warmed
+
     def submit_task(self, task_func: Callable, callback: Callable, *args, **kwargs) -> bool:
         """
         提交任务到队列