Django日志模块logging进程报错

Django使用logging模块里的时间分割和文件大小分割记录日志

RotatingFileHandler和TimedRotatingFileHandler在生成新的文件时，会抛出 PermissionError 异常(其它分割文件的也同样会出现)

Watching for file changes with StatReloader
[INFO][2021-12-30 21:43:35,642] Watching for file changes with StatReloader
--- Logging error ---
Traceback (most recent call last):
  File "d:pythonpython3.8liblogginghandlers.py", line 69, in emit
    self.doRollover()
  File "d:pythonpython3.8liblogginghandlers.py", line 393, in doRollover
    self.rotate(self.baseFilename, dfn)
  File "d:pythonpython3.8liblogginghandlers.py", line 110, in rotate
    os.rename(source, dest)
PermissionError: [WinError 32] 另一个程序正在使用此文件，进程无法访问。: 'D:\python_sxt\Envs\django\logger_study\log\logging_study_timed.log' -> 'D:\python_sxt\Envs\django\logger_study\log\logging_study_timed.log.2021-12-30_21-42-38'
Call stack:
  File "manage.py", line 23, in 
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagement__init__.py", line 425, in execute_from_command_line
    utility.execute()
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagement__init__.py", line 419, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagementbase.py", line 373, in run_from_argv
    self.execute(*args, **cmd_options)
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagementcommandsrunserver.py", line 66, in execute
    super().execute(*args, **options)
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagementbase.py", line 417, in execute
    output = self.handle(*args, **options)
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagementcommandsrunserver.py", line 101, in handle
    self.run(**options)
  File "D:python_sxtEnvsdjango_envlibsite-packagesdjangocoremanagementcommandsrunserver.py", line 108, in run
Performing system checks...

4040
System check identified no issues (0 silenced).

如上图，通过查看资源管理器发现创建应用会启用两个python进程，因为我开启了pipenv所以图上是四个

DJango默认会开启两个进程：第一个是reload自动重载，第二个才是Django主应用

目前找到以下几种解决方案：

在manage文件后面加启动参数 --noreload  关闭自动重载

python manage.py runserver --noreload

效果：

 可以看到关闭自动重载后，python主进程之开了一个，而且没有报错

 缺点：一棒子打死，别的代码修改也不能自动重载，只能手动重启

使用模块concurrent_log_handler

pip install concurrent_log_handler #安装模块

#setting.py
import concurrent_log_handler    #导入模块

······

LOGGING = {
    ······
    'handlers': {
        ······
        },
        'file': {
            'level': 'INFO',
            'class': 'concurrent_log_handler.ConcurrentRotatingFileHandler',#修改这里
            'filename': os.path.join(base_LOG_DIR, "log_study.log"), 
            'maxBytes': 1024 * 1024 * 50,
            'backupCount': 3, 
            'formatter': 'standard',
            'encoding': 'utf-8',
        },
    },
    'loggers': {
        '': {
            'handlers': ['console', 'file'],
            'level': 'DEBUG',
        },
    },
}

concurrent_log_handler适用于windows系统

linux需要安装ConcurrentLogHandler

使用进程id 命名log文件

#setting.py
import os

base_LOG_DIR = os.path.join(base_DIR, "log")
loggerpid = str(os.getpid())
LOGGING = {
    ······
        'timed_file': {
        ······
            'filename': os.path.join(base_LOG_DIR,f"logging_study_timed{loggerpid}.log"),
            ······
        },
}

添加delay参数为True

'delay': True,