# sqlalchemy.exc.TimeoutError：QueuePool 大小限制 5，溢出 10 已达到，连接超时，超时时间 30

- **ID:** `python/sqlalchemy-timeout-connection-pool`
- **领域:** python
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

连接池耗尽，由于并发请求过多或查询缓慢。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 3.x | active | — | — |

## 解决方案

1. **Optimize pool settings based on load.** (85% 成功率)
   ```
   engine = create_engine(url, pool_size=10, max_overflow=20, pool_timeout=60)
   ```
2. **Use connection pooling monitoring and release connections promptly.** (90% 成功率)
   ```
   with engine.connect() as conn:
    # use connection
    pass  # automatically returned to pool
   ```

## 无效尝试

- **Increasing pool_size and max_overflow to very high values.** — May overwhelm database server with too many connections. (60% 失败率)
- **Disabling connection pooling entirely.** — Creates new connection for each request, increasing latency. (70% 失败率)