celery beat 按照间隔运行任务，被集群中可用的工作进程来运行。

添加周期任务：

from celery import Celery
from celery.schedules import crontab

app = Celery()

@app.on_after_configure.connect
def setup_periodic_tasks(sender, **kwargs):
    # Calls test('hello') every 10 seconds.
    sender.add_periodic_task(10.0, test.s('hello'), name='add every 10')

    # Calls test('world') every 30 seconds
    sender.add_periodic_task(30.0, test.s('world'), expires=10)

    # Executes every Monday morning at 7:30 a.m.
    sender.add_periodic_task(
        crontab(hour=7, minute=30, day_of_week=1),
        test.s('Happy Mondays!'),
    )

@app.task
def test(arg):
    print(arg)

或

app.conf.beat_schedule = {
    'add-every-30-seconds': {
        'task': 'tasks.add',
        'schedule': 30.0,
        'args': (16, 16)
    },
}
app.conf.timezone = 'UTC'

crontab

app.conf.beat_schedule = {
    # Executes every Monday morning at 7:30 a.m.
    'add-every-monday-morning': {
        'task': 'tasks.add',
        'schedule': crontab(hour=7, minute=30, day_of_week=1),
        'args': (16, 16),
    },
}

例子：

crontab() Execute every minute.
crontab(minute=0, hour=0) Execute daily at midnight.
crontab(minute=0, hour='/3') Execute every three hours: midnight, 3am, 6am, 9am, noon, 3pm, 6pm, 9pm.
crontab(minute=0,
hour='0,3,6,9,12,15,18,21')
Same as previous.
crontab(minute='/15') Execute every 15 minutes.
crontab(day_of_week='sunday') Execute every minute (!) at Sundays.
crontab(minute='',
hour='', day_of_week='sun')
Same as previous.
crontab(minute='/10',
hour='3,17,22', day_of_week='thu,fri')
Execute every ten minutes, but only between 3-4 am, 5-6 pm, and 10-11 pm on Thursdays or Fridays.
crontab(minute=0, hour='/2,/3') Execute every even hour, and every hour divisible by three. This means: at every hour except: 1am, 5am, 7am, 11am, 1pm, 5pm, 7pm, 11pm
crontab(minute=0, hour='/5') Execute hour divisible by 5. This means that it is triggered at 3pm, not 5pm (since 3pm equals the 24-hour clock value of “15”, which is divisible by 5).
crontab(minute=0, hour='/3,8-17') Execute every hour divisible by 3, and every hour during office hours (8am-5pm).
crontab(0, 0, day_of_month='2') Execute on the second day of every month.
crontab(0, 0,
day_of_month='2-30/3')
Execute on every even numbered day.
crontab(0, 0,
day_of_month='1-7,15-21')
Execute on the first and third weeks of the month.
crontab(0, 0, day_of_month='11',
month_of_year='5')
Execute on the eleventh of May every year.
crontab(0, 0,
month_of_year='/3')
Execute on the first month of every quarter.

solar schedules

from celery.schedules import solar

app.conf.beat_schedule = {
    # Executes at sunset in Melbourne
    'add-at-melbourne-sunset': {
        'task': 'tasks.add',
        'schedule': solar('sunset', -37.81753, 144.96715),
        'args': (16, 16),
    },
}

根据日出日落时间，指定经纬度

dawn_astronomical Execute at the moment after which the sky is no longer completely dark. This is when the sun is 18 degrees below the horizon.
dawn_nautical Execute when there’s enough sunlight for the horizon and some objects to be distinguishable; formally, when the sun is 12 degrees below the horizon.
dawn_civil Execute when there’s enough light for objects to be distinguishable so that outdoor activities can commence; formally, when the Sun is 6 degrees below the horizon.
sunrise Execute when the upper edge of the sun appears over the eastern horizon in the morning.
solar_noon Execute when the sun is highest above the horizon on that day.
sunset Execute when the trailing edge of the sun disappears over the western horizon in the evening.
dusk_civil Execute at the end of civil twilight, when objects are still distinguishable and some stars and planets are visible. Formally, when the sun is 6 degrees below the horizon.
dusk_nautical Execute when the sun is 12 degrees below the horizon. Objects are no longer distinguishable, and the horizon is no longer visible to the naked eye.
dusk_astronomical Execute at the moment after which the sky becomes completely dark; formally, when the sun is 18 degrees below the horizon.

启动

celery -A proj beat

或者可以在启动普通工作进程时把定时任务工作进程嵌入

celery -A proj worker -B

因为需要记录上次运行时间，以上命令需要celery在当前路径有读写权限，也可以指定：

celery -A proj beat -s /home/celery/var/run/celerybeat-schedule

默认使用的scheduler类是 [celery.beat.PersistentScheduler]是把上次运行时间保存在了本地的shelve数据库，可以把它存在django的数据库中这样好管理。

pip install django-celery-beat

INSTALLED_APPS = (
    ...,
    'django_celery_beat',
)

python manage.py migrate

celery -A proj beat -l info -S django