Creating PeriodicTask in celery django - django

I need to send notifications with certain interval when Ticket model instance has been created. For that I decided to use celery-beat.
I created signals.py where I create PeriodicTask intance. When I create new Ticket instance the PeriodicTask instance is created in DB but the task is not running. What do I do wrong?
signals.py
from datetime import datetime
from django.db.models.signals import post_save
from django.dispatch import receiver
from .models import Ticket
from django_celery_beat.models import PeriodicTask, IntervalSchedule
import json
#receiver(post_save,sender=Ticket)
def notification_handler(sender, instance, created, **kwargs):
if created:
interval, created = IntervalSchedule.objects.get_or_create(every=10, period='seconds')
task = PeriodicTask.objects.create(interval=interval,enabled=True, name='notification_' + str(instance.id), task="create", args=json.dumps((instance.id, )))
tasks.py
from celery import shared_task
#shared_task(name="create")
def create(data):
print("Some logic here")
celery.py
import os
from celery import Celery
# Set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'helpdesk.settings')
app = Celery('helpdesk')
# Using a string here means the worker doesn'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 apps.
app.autodiscover_tasks()
setting.py
CELERY_BROKER_URL = 'redis://redis:6379/0'
The commands I use for launching celery and celery-beat:
beat:
celery -A helpdesk beat
celery:
celery -A helpdesk worker -l INFO --pool=solo

It seems I found the answer. It's needed to launch celery-beat with that command:
celery -A <your_project_name> beat -l INFO --scheduler django_celery_beat.schedulers:DatabaseScheduler

Related

Django: How to run a celery task only on start up?

I have a django app that uses celery to run tasks.
Sometimes, I have a "hard shutdown" and a bunch of models aren't cleaned up.
I created a task called clean_up that I want to run on start up.
Here is the tasks.py
from my_app.core import utils
from celery import shared_task
#shared_task
def clean_up():
f_name = clean_up.__name__
utils.clean_up()
Here is what celery.py looks like:
import os
from celery import Celery
from celery.schedules import crontab
from datetime import timedelta
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "my_app.settings")
app = Celery("proj")
app.config_from_object("django.conf:settings", namespace="CELERY")
# Load task modules from all registered Django apps.
app.autodiscover_tasks()
app.conf.beat_schedule = {
"runs-on-startup": {
"task": "my_app.core.tasks.clean_up",
"schedule": timedelta(days=1000),
},
}
#app.task(bind=True)
def debug_task(self):
print(f"Request: {self.request!r}")
How can I change celery.py to run clean_up only on start up?
Extra info:
this is in a docker compose, so by "hard shutdown" I mean docker compose down
By "on start up" I mean docker compose up
you were looking for signal:
tasks.py add following code:
from celery import signals
#signals.worker_ready.connect
def clean(**kwargs):
...
loggert.info('worker_ready')

Celery beat sends scheduled task only once and then doesn't send task when restarted

I am using Celery beat to perform a task that is supposed to be executed at on specific time. I was trying to excute it now by changing the time just to see if it works correctly. What I have noticed is it sends the task correctly when I run a fresh command that is celery -A jgs beat -l INFO but then suppose I change the time in the schedule section from two minutes or three minutes from now and then again run the above command, beat does not send the task. Then I noticed something strange. If I go to the admin area and delete all the other old tasks that were created in the crontab table, and then run the command again it sends the task again to the worker.
The tasks are being traced by the worker correctly and also the celery worker is working correctly. Below are the codes that I wrote to perform the task.
celery.py
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
from django.conf import settings
from celery.schedules import crontab
from django.utils import timezone
from datetime import timezone
# Set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'jgs.settings')
app = Celery('jgs')
# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
# should have a `CELERY_` prefix.
app.conf.enable_utc = False
app.conf.update(timezone = 'Asia/Kolkata')
# app.conf.update(BROKER_URL=os.environ['REDIS_URL'],
# CELERY_RESULT_BACKEND=os.environ['REDIS_URL'])
app.config_from_object('django.conf:settings', namespace='CELERY')
# Celery beat settings
app.conf.beat_schedule = {
'send-expiry-email-everyday': {
'task': 'control.tasks.send_expiry_mail',
'schedule': crontab(hour=1, minute=5),
}
}
# Load task modules from all registered Django apps.
app.autodiscover_tasks()
#app.task(bind=True)
def debug_task(self):
print(f'Request: {self.request!r}')
control/tasks.py
from celery import shared_task
from django.core.mail import message, send_mail, EmailMessage
from django.conf import settings
from django.template.loader import render_to_string
from datetime import datetime, timedelta
from account.models import CustomUser
from home.models import Contract
#shared_task
def send_expiry_mail():
template = render_to_string('expiry_email.html')
email = EmailMessage(
'Registration Successfull', #subject
template, # body
settings.EMAIL_HOST_USER,
['emaiid#gmail.com'], # sender email
)
email.fail_silently = False
email.content_subtype = 'html' # WITHOUT THIS THE HTML WILL GET RENDERED AS PLAIN TEXT
email.send()
return "Done"
settings.py
############# CELERY SETTINGS #######################
CELERY_BROKER_URL = 'redis://127.0.0.1:6379'
# CELERY_BROKER_URL = os.environ['REDIS_URL']
CELERY_ACCEPT_CONTENT =['application/json']
CELERY_RESULT_SERIALIZER = 'json'
CELERY_TASK_SERIALIZER = 'json'
CELERY_TIMEZONE = 'Asia/Kolkata'
CELERY_RESULT_BACKEND = 'django-db'
# CELERY BEAT CONFIGURATIONS
CELERY_BEAT_SCHEDULER = 'django_celery_beat.schedulers:DatabaseScheduler'
commands that I am using
for worker
celery -A jgs.celery worker --pool=solo -l info
for beat
celery -A jgs beat -l INFO
Please correct me where I going wrong or what I am writing wrong, I completely in beginer phase in this async part.
I am really sorry if my sentences were confusing above.

celery not working in django and just waiting (pending)

i'm trying found how celery is working. i have a project that have about 10 app.now i want use celery .
setting.py:
CELERY_BROKER_URL = 'amqp://rabbitmq:rabbitmq#localhost:5672/rabbitmq_vhost'
CELERY_RESULT_BACKEND = 'redis://localhost'
i created a user in rabbitmq with this info:username: rabbitq and password:rabbitmq . then i create a vhost with name rabbitmq_vhost and add rabbitmq permission to it. all is fine i think because all of error about rabbitmq disappear .
here is my test.py:
from .task import when_task_expiration
def test_celery():
result = when_task_expiration.apply_async((2, 2), countdown=3)
print(result.get())
task.py:
from __future__ import absolute_import, unicode_literals
import logging
from celery import shared_task
from proj.celery import app
#app.task
def when_task_expiration(task, x):
print(task.id, 'task done')
return True
celery.py:
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'proj.settings')
app = Celery('proj')
# Using a string here means the worker doesn'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()
now when i call test_celery() in python shell it's pending.i try to replace #shared_task and #app.task(bind=True) but noting changed.even i try use .delay() instead apply_async((2, 2), countdown=3) and again nothing happend.
i'm trying to use celery to call a function in specific time during this quesation that i ask in past.thank you.
You most likely forgot to run at least one Celery worker process. To do so, execute the following in the shell: celery worker -A proj.celery -c 4 -l DEBUG (here I assumed your Celery application is defined in proj/celery.py as you have Celery('proj') in there)

if a task call with delay() when will execute exactly?

I'm new in celery and i want use it but i don't know when i call a task with delay() when exactly will execute? and after adding a new task what i must to do to this task work correctly? i use a present project and i extending it, but old task work correctly and my task doesn't .
present app1/task.py:
from __future__ import absolute_import, unicode_literals
import logging
logger = logging.getLogger('notification')
#shared_task
def send_message_to_users(users, client_type=None, **kwargs):
.
.
#doing something here
.
.
logger.info(
'notification_log',
exc_info=False,
)
)
and this is my code in app2/task.py:
#shared_task
def update_students_done_count(homework_id):
homework_students = HomeworkStudent.objects.filter(homework_id=homework_id)
students_done_count = 0
for homework_student in homework_students:
if homework_student.student_homework_status:
students_done_count += 1
homework = get_object_or_404(HomeWork, homework_id=homework_id)
homework.students_done_count = students_done_count
homework.save()
logger.info(
'update_students_done_count_log : with id {id}'.format(id=task_id),
exc_info=False,
)
sample of how both task calling:
send_message_to_users.delay(users = SomeUserList)
update_students_done_count.delay(homework_id=SomeHomeWorkId)
project/celery.py:
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'hamclassy.settings')
app = Celery('hamclassy')
# Using a string here means the worker doesn'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()
projetc/init.py:
from __future__ import absolute_import, unicode_literals
# This will make sure the app is always imported when
# Django starts so that shared_task will use this app.
from .celery import app as celery_app
__all__ = ['celery_app']
after any change to task i run workers by this command:
celery -A project worker -l info
when i calling update_students_done_count.delay(homework_id=1) in an endpoint the log shown me that recived task but how much i'm waiting the task not execute. any idea?thank you

Celery + Django not working at the same time

I have Django 2.0 project that is working fine, its integrated with Celery 4.1.0, I am using jquery to send ajax request to the backend but I just realized its loading endlessly due to some issues with celery.
Celery Settings (celery.py)
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'converter.settings')
app = Celery('converter', backend='amqp', broker='amqp://guest#localhost//')
# Using a string here means the worker doesn'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.task(bind=True)
def debug_task(self):
print('Request: {0!r}'.format(self.request))
Celery Tasks (tasks.py)
from __future__ import absolute_import, unicode_literals
from celery import shared_task
#shared_task(time_limit=300)
def add(number1, number2):
return number1 + number2
Django View (views.py)
class AddAjaxView(JSONResponseMixin, AjaxResponseMixin, View):
def post_ajax(self, request, *args, **kwargs):
url = request.POST.get('number', '')
task = tasks.convert.delay(url, client_ip)
result = AsyncResult(task.id)
data = {
'result': result.get(),
'is_ready': True,
}
if result.successful():
return self.render_json_response(data, status=200)
When I send ajax request to the Django app it is loading endlessly but when terminate Django server, and I run celery -A demoproject worker --loglevel=info that's when my tasks are running.
Question
How do I automate this so that when I run Django project my celery tasks will work automatically when I send ajax request?
If you are on development environment, you have to run manually celery worker as it does not run automatically on the background, in order to process the jobs in the queue. So if you want to have a flawless workflow, you need both Django default server and celery worker running. As stated in the documentation:
In a production environment you’ll want to run the worker in the background as a daemon - see Daemonization - but for testing and development it is useful to be able to start a worker instance by using the celery worker manage command, much as you’d use Django’s manage.py runserver:
celery -A proj worker -l info
You can read their documentation for daemonization.
http://docs.celeryproject.org/en/latest/userguide/daemonizing.html