Celery beat not sending crontab task when hour is set

Question

I'm using celery 4.1 and all my periodic tasks work correctly except where I set the hour in a crontab task. I was thinking it had something to do with the timezone setting, but I can't seem to work out where the problem is.

dashboard/celery.py

from __future__ import absolute_import, unicode_literals
from celery import Celery

app = Celery('dashboard',
         broker='redis://',
         backend='redis://localhost',
         include=['dashboard.tasks'])

app.conf.update(
    result_expires=3600,
    enable_utc = False,
    timezone = 'America/New_York'
)


if __name__ == '__main__':
    app.start()

This works:

@app.task
@periodic_task(run_every=(crontab()))
def shutdown_vms():
    inst = C2CManage(['stop','kube'])
    inst.run()
    return

This works:

@app.task
@periodic_task(run_every=(crontab(minute=30,hour='*')))
def shutdown_vms():
    inst = C2CManage(['stop','kube'])
    inst.run()
    return

This doesn't work:

@app.task
@periodic_task(run_every=(crontab(minute=30,hour=6)))
def shutdown_vms():
    inst = C2CManage(['stop','kube'])
    inst.run()
    return

Beat picks up the task just fine:

<ScheduleEntry: dashboard.tasks.shutdown_vms dashboard.tasks.shutdown_vms() <crontab: 30 6 * * * (m/h/d/dM/MY)>

But it never sends it. I've let the processes run over a weekend and it never submits the task. I don't know what I'm doing wrong. I do have other tasks that run on timedelta periodicity and they all work perfectly.

Any help would be awesome.

EDIT: host is set to use the America/New_York timezone.

EDIT2: running beat as a separate process:

celery -A dashboard worker -l info

celery -A dashboard beat -l debug

I run them detached mostly or use multi.

score 3 · Answer 1 · edited Feb 09 '23 at 14:29

3

An easy solution for the problem is

In celery settings update the following config

app.conf.enable_utc = False
app.conf.timezone = "Asia/Calcutta" #change to your timezone

edited Feb 09 '23 at 14:29

adhg

10,437
12
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94

answered Oct 22 '21 at 11:18

Anurag Misra

1,516
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24

HM is the hero of the day. How come I didn't see that :-) Thanks!!! – adhg Feb 09 '23 at 14:28

score 2 · Accepted Answer · answered Nov 07 '17 at 12:44

2

Looks like this bug is causing it.

https://github.com/celery/celery/issues/4177

And several others that indicate that scheduling is not calculated properly when not using UTC.

Switched celery to use UTC as timezone and enabled utc and it works fine.

answered Nov 07 '17 at 12:44

Drew

491
5
9

How did you do that? – MyopicVisage Dec 03 '18 at 22:54
Sorry for the late reply: `app.conf.update( result_expires=3600, enable_utc = true, timezone = 'UTC' )` – Drew Mar 19 '19 at 19:19

score 2 · Answer 3 · answered Nov 23 '17 at 03:06

2

I solve this problem by use celery==4.0.1

answered Nov 23 '17 at 03:06

guangyao

87
5

1

Fixed it for me too... It really irks me the dev team at celery has all the time in the world to add backend kind 12, exotic feature xyz and now change the entire settings naming convention to 'lower case' as if that really helps anyone when they can't even keep celery stable for its main purpose - running tasks on time. – Kevin Parker Dec 06 '17 at 06:12
For me I started with celery 4.1 and using UTC was a good solution. Whatever helps you get it working is the way to go though. I agree with you on the "priority" of the work getting done, but it's hard to complain when folks support things in their spare time... – Drew Dec 18 '17 at 19:19
When I use celery 4.1 and set timezone UTC, the time is not correct UTC time – guangyao Dec 21 '17 at 08:22

Celery beat not sending crontab task when hour is set

3 Answers3