Python | peewee.InterfaceError

Python | peewee.InterfaceError

1. 简介

服务器上运行的Python后台，每次到第二天就会出现后台管理账号无法登录情况。查看后台日志发现是数据库方面出现了问题，最先以为是数据库无法访问。因为后台有正在运行的任务，会经常访问数据库发现并没有报数据库方面的错，只有HTTP请求的线程无法访问。

(0, '') <class 'peewee.InterfaceError'>, (0, ''), [<FrameSummary file /flask/router/user.py, line 29 in login>, <FrameSummary file /flask/service/user.py, line 19 in login_user>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 6522 in get>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 6970 in get>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 1918 in inner>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 1989 in execute>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 2162 in _execute>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 3190 in execute>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 3174 in execute_sql>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 2950 in __exit__>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 191 in reraise>, <FrameSummary file /usr/local/lib/python3.10/site-packages/peewee.py, line 3177 in execute_sql>, <FrameSummary file /usr/local/lib/python3.10/site-packages/pymysql/cursors.py, line 148 in execute>, <FrameSummary file /usr/local/lib/python3.10/site-packages/pymysql/cursors.py, line 310 in _query>, <FrameSummary file /usr/local/lib/python3.10/site-packages/pymysql/connections.py, line 547 in query>, <FrameSummary file /usr/local/lib/python3.10/site-packages/pymysql/connections.py, line 793 in _execute_command>]

2. 原因

peewee会为每个线程分配一条数据库链接，当页面长时间没有收到HTTP请求数据操作数据库时，处理HTTP请求的线程的数据库连接就会失效，所有会出现页面无法登录，而后台运行的任务会经常访问数据库，所有连接不会失效。

3. 问题复现

第1步修改数据库wait_timeout时间

让连接更快失效，这里将超时时间设置为3秒。

# 查看数据库wait_timeout
show global variables like 'wait_timeout';

# 设置数据库wait_time
set global wait_timeout=3;

第2步执行测试代码

import time

from peewee import *

db = MySQLDatabase(
    'test',<