Question 121546 in Redis Question posted in
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Redis – Celery jobs not running on heroku (python/django app)

I have a Django app setup with some scheduled tasks. The app is deployed on Heroku with Redis. The task runs if invoked synchronously in the console, or locally when I also have redis and celery running. However, the scheduled jobs are not running on Heroku.

My task:

@shared_task(name="send_emails")
def send_emails():
.....

celery.py:

from __future__ import absolute_import, unicode_literals

import os
from celery import Celery
from celery.schedules import crontab

# set the default Django settings module for the 'celery' program.
# this is also used in manage.py
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'my_app.settings')

# Get the base REDIS URL, default to redis' default
BASE_REDIS_URL = os.environ.get('REDIS_URL', 'redis://localhost:6379')

app = Celery('my_app')

# Using a string here means the worker don't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
#   should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')

# Load task modules from all registered Django app configs.
app.autodiscover_tasks()

app.conf.broker_url = BASE_REDIS_URL

# this allows you to schedule items in the Django admin.
app.conf.beat_scheduler = 'django_celery_beat.schedulers.DatabaseScheduler'

# These are the scheduled jobs
app.conf.beat_schedule = {
    'send_emails_crontab': {
        'task': 'send_emails',
        'schedule': crontab(hour=9, minute=0),
        'args': (),
    }
}

In Procfile:
worker: celery -A my_app worker --beat -S django -l info

I’ve spun up the worker with heroku ps:scale worker=1 -a my-app.
I can see the registered tasks under [tasks] in the worker logs.
However, the scheduled tasks are not running at their scheduled time. Calling send_emails.delay() in the production console does work.
How do I get the worker to stay alive and / or run the job at the scheduled time?

I have a workaround using a command and heroku scheduler. Just unsure if that’s the best way to do it.

Tags:

2

Answers


  1. 0

    If you’re on free demo, you should know that heroku server sleeps and if your scheduled task becomes due when your server is sleeping, it won’t run.

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  2. 0

    I share you any ideas.

    1. Run console and get the datetime of Dyno. The Dyno use a localtime US.

    2. The DynoFree sleeps each 30 minutes and only 450 hours/month.

    3. Try change celery to BackgroundScheduler,
      you need add a script clock.py as:

       from myapp import myfunction
 from datetime import datetime
 from apscheduler.schedulers.background import BackgroundScheduler
 from apscheduler.schedulers.blocking import BlockingScheduler
 from time import monotonic, sleep, ctime
 import os

 sched = BlockingScheduler()
 hour = int(os.environ.get("SEARCH_HOUR"))
 minutes = int(os.environ.get("SEARCH_MINUTES"))

 @sched.scheduled_job('cron', day_of_week='mon-sun', hour=hour, minute = minutes)
 def scheduled_job():
     print('This job: Execute myfunction every at ', hour, ':', minutes)        
     #My function
     myfunction()

 sched.start(

    )

    In Procfile:

    clock: python clock.py

    and run:

    heroku ps:scale clock=1 --app thenameapp

    Regards.

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