After that gunicorn will call system's fork method. # I run scheduler - It will create a new thread!Īfter running this code the master gunicorn process will load the whole django project in memory, so it will execute `start_scheduler` once and a new thread is spun up in the background, which is responsible for scheduling jobs. Why is this will help? Because look at start_scheduler() def start_scheduler(): So our code will be executed in main process and only after that it will be forked. This option means Load application code before the worker processes are forked. Well, you can start gunicorn with -preload option. How can I change Gunicorn settings to run only one BackgroundScheduler? (not a good idea too) In production I use Gunicorn so it will fork the main process into additional worker processes and I will have 5 copies (depending on settings) of my BackgroundScheduler, and every task will be enqueued 5 times. It's because manage.py runserver runs django twice in two separate processes (one for serving requests and another to auto-reload), and each process executed our ready() function. And background tasks will be executed twice. periodic_tasks import start_schedulerīut if you will start your django dev server - you will see two Starting background scheduler lines. Scheduler.add_job(periodically_run_job, every_minute)Īnd then: from django.apps import AppConfigįrom. Scheduler = BackgroundScheduler(timezone=UTC)Įvery_minute = CronTrigger(minute=1, timezone=UTC) Logging.warning(f'Starting background scheduler.') Logging.warning('Starting dramatiq task') I updated periodic_tasks.py as follows: import loggingįrom import BackgroundSchedulerįrom import CronTrigger This scheduler runs in the background using a separate thread. If you need my final solution - just click here Simple and naive approach (not a good idea)Īt first I've decided to use BackgroundScheduler class from apscheduler. Logging.warning('It is time to start the dramatiq task')ĭirectory structure of task_scheduler django app. It can prepare some data and parameters and then enqueue background task.""" Logging.warning('Task is ended') tasks.py (djang-dramatiq will auto-discover functions in this file) import logging Logging.warning('Start my long-running task') """Very simple task for demonstrating purpose.""" I configured django-dramatiq and started to work on periodical tasks.įor this article I will be using very simple task import logging.You can read about in django documentation. (NOTE - I use this form instead of just writing task_scheduler to be able to use `AppConfig.ready()` function. I created new django app via python manage.py startapp task_scheduler. ![]() I installed the dramatiq, django-dramatiq, and APScheduler packages from pypi.Here are some approaches I've used and my discoveries. APScheduler is the recommended scheduler to use with Dramatiq (dramatiq documentation) So I needed some kind of scheduler to start those tasks on time. For that I decided to use dramatiq - a very nice background task processing library.Īfter that I had a new task - we needed to run periodical processing tasks (import some data, calculate some statistics, etc.). Working on one of my django projects I had to do long-running computations in the background.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |