【celery】不发送任务“beat: Waking up in 5.00 minutes”

问题

项目中的celery突然就不能正常工作了，排查了很久，发现就是celery一直不发送出数据出来，启动beat进程后控制台最后输出了“beat: Waking up in 5.00 minutes”，然后一直在阻塞中：

$ celery beat -A tasks.tasks -l debug
celery beat v4.3.0 (rhubarb) is starting.
__    -    ... __   -        _
LocalTime -> 2021-08-11 18:47:59
Configuration ->
    . broker -> redis://:**@127.0.0.1:6378/8
    . loader -> celery.loaders.app.AppLoader
    . scheduler -> celery.beat.PersistentScheduler
    . db -> celerybeat-schedule
    . logfile -> [stderr]@%DEBUG
    . maxinterval -> 5.00 minutes (300s)
[2021-08-11 18:47:59,767: DEBUG/MainProcess] Setting default socket timeout to 30
[2021-08-11 18:47:59,767: INFO/MainProcess] beat: Starting...
[2021-08-11 18:47:59,792: DEBUG/MainProcess] Current schedule:



[2021-08-11 18:47:59,792: DEBUG/MainProcess] beat: Ticking with max interval->5.00 minutes
[2021-08-11 18:47:59,793: DEBUG/MainProcess] beat: Waking up in 5.00 minutes.

解决方案：
问题的原因没有找到为什么，但是通过网上的有些讨论，将celery项目目录下的celerybeat-schedule删除掉即可。