celery beat raised exception <class '_dbm.error'>: error('cannot add item to database',）错误解决方法

╰半橙微兮° 2022-05-27 04:19 233阅读 0赞

在一次重启python中的celery-beat任务中，发现celery-beat启动不起来了。报错信息如下：

celery beat v4.1.0 (latentcall) is starting.
    __    -    ... __   -        _
    LocalTime -> 2018-04-11 15:04:12
    Configuration ->
        . broker -> redis://127.0.0.1:9736/4
        . loader -> celery.loaders.app.AppLoader
        . scheduler -> celery.beat.PersistentScheduler
        . db -> celerybeat-schedule
        . logfile -> [stderr]@%WARNING
        . maxinterval -> 5.00 minutes (300s)
    [2018-04-11 15:04:12,478: CRITICAL/MainProcess] beat raised exception <class '_dbm.error'>: error('cannot add item to database',)
    Traceback (most recent call last):
      File "/usr/local/lib/python3.6/site-packages/kombu/utils/objects.py", line 42, in __get__
        return obj.__dict__[self.__name__]
    KeyError: 'scheduler'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "/usr/local/lib/python3.6/shelve.py", line 111, in __getitem__
        value = self.cache[key]
    KeyError: 'entries'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 485, in _create_schedule
        self._store[str('entries')]
      File "/usr/local/lib/python3.6/shelve.py", line 113, in __getitem__
        f = BytesIO(self.dict[key.encode(self.keyencoding)])
    KeyError: b'entries'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "/usr/local/lib/python3.6/site-packages/celery/apps/beat.py", line 107, in start_scheduler
        service.start()
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 549, in start
        humanize_seconds(self.scheduler.max_interval))
      File "/usr/local/lib/python3.6/site-packages/kombu/utils/objects.py", line 44, in __get__
        value = obj.__dict__[self.__name__] = self.__get(obj)
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 593, in scheduler
        return self.get_scheduler()
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 588, in get_scheduler
        lazy=lazy,
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 428, in __init__
        Scheduler.__init__(self, *args, **kwargs)
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 206, in __init__
        self.setup_schedule()
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 456, in setup_schedule
        self._create_schedule()
      File "/usr/local/lib/python3.6/site-packages/celery/beat.py", line 489, in _create_schedule
        self._store[str('entries')] = {}
      File "/usr/local/lib/python3.6/shelve.py", line 125, in __setitem__
        self.dict[key.encode(self.keyencoding)] = f.getvalue()
    _dbm.error: cannot add item to database

解决办法：

1.删除启动目录中的celerybeat-schedule.db（我的项目地址为/data/www/master/project，在这目录下你发现有个 celerybeat-schedule.db文件，删除即可）

2.再重新启动 ( celery beat -A project.celery\_job )

原因：

当celerybeat启动的时候会带启动目录中生成 celerybeat-schedule.db作为数据存储的文件，当celerybeat异常关闭时，此文件没有被删除，在下一下启动的时候，被占用，导致\_dbm.error: cannot add item to database错误。所以把文件删除就可以了