django —— Celery实现异步和定时任务

1. 环境

python==2.7

djang==1.11.2  # 1.8, 1.9, 1.10应该都没问题

celery-with-redis==3.0  # 需要用到redis作为中间人服务(Broker)
celery==3.1.25  # 安装上面的会自动安装
kombu==3.0.37
billiard==3.3.0.23

django-celery==3.2.2  # celery插件, 实现定时任务

celery>=4.0 对此环境会有报错, 暂不建议在此环境下使用

2. 安装

pip install django==1.11.2 celery-with-redis==3.0 django-celery==3.2.2

3. 安装Redis, 用作Broker (RabbitMQ 官方推荐, 但安装麻烦点)

教程很多, 略

4. 新建django项目

- Demo
  - Demo
    setting.py
    wsgi.py
    urls.py
  - app
    - migrations
    models.py
    views.py
    ...

• 配置settings.py

INSTALLED_APPS = (
    ...
    'app',
    'djcelery',# django-celery 可以在admin后台定义定时任务, 开始前需要直接migrate
)

BROKER_URL = 'redis://127.0.0.1:6379/0'
BROKER_TRANSPORT = 'redis'

CELERYBEAT_SCHEDULER = 'djcelery.schedulers.DatabaseScheduler'  # 数据库调度

• 新建文件Demo/Demo/celery.py

from __future__ import absolute_import

import os

from celery import Celery

# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'Demo.settings')

from django.conf import settings  # noqa

app = Celery('Demo')

# Using a string here means the worker will not have to
# pickle the object when using Windows.
app.config_from_object('django.conf:settings')
app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)

@app.task(bind=True)
def debug_task(self):
    print('Request: {0!r}'.format(self.request))

• 新建Demo/app/tasks.py

from Demo.celery import app

@app.task
def cus_task(*arg):
    print('This is a test task')

• 编辑Demo/app/views.py

from django.shortcuts import render, HttpResponse

from .tasks import cus_task

def index(request):
    cus_task.delay()
    return HttpResponse("Test async task")

• 启动django和celery

# django
python manage.py runserver

# celery
celery -A Demo worker -l debug

admin后台中配置celery计划

• 配置

• # 如上settings.py中的设置, 后执行
  python manage.py migrate djcelery

• 登陆admin后台进行配置

• # Djcelery模块列表
  
  Crontabs  # 同linux crontab
  Intervals  # 间隔
  Periodic tasks  # 周期任务
  Tasks
  Workers

　　配置一个periodic task任务内容 app.tasks.cus_task 用crontab或interval设置每5s执行一次

• 启动django和celery, 并查看日志

• celery -A Demo worker -l debug
  
  # 另一个窗口
  celery -A Demo beat -l debug --max-interval=10  # 每10s扫描一次djcelery任务

nohup 后台启动

nohup celery -A Demo worker -l debug > abc.log &