前言: 針對高延時任務, 直接在一次網絡請求中處理完畢會導致很不好的體驗, celery則可以不阻塞請求后臺處理這些任務, 并且可以使用django的models進行數據庫操作.

環境

python models:

• celery-4.1.1
• redis-2.10.6
• django-1.11.7

其他:

• redis-3.2.9
• macos
• python3.6

創建django工程

django-admin startproject dc
cd dc
django-admin startapp main

此時項目結構如下

dc
|-- __init__.py
|-- main
|   |-- __init__.py
|   |-- admin.py
|   |-- apps.py
|   |-- migrations
|   |   `-- __init__.py
|   |-- models.py
|   |-- tests.py
|   `-- views.py
|-- settings.py
|-- urls.py
`-- wsgi.py

修改settings.py, 添加app

INSTALLED_APPS = ['django.contrib.admin','django.contrib.auth','django.contrib.contenttypes','django.contrib.sessions','django.contrib.messages','django.contrib.staticfiles','dc.main' //new added
]

修改dc/main/models.py, 創建新models

from django.db import models# Create your models here.class Person(models.Model):first_name = models.CharField(max_length=30)last_name = models.CharField(max_length=30)

創建根訪問節點

dc/main/views.py

from django.shortcuts import render
from django.http import HttpResponse
# Create your views here.def hello(request):return HttpResponse('hello world')

dc/urls.py

urlpatterns = [url(r'^admin/', admin.site.urls),url(r'^$', hello) //new added
]

依次執行以下語句, 初始化django各功能模塊

python manage.py migrate
python manage.py makemigrations main
python manage.py sqlmigrate main 0001
python manage.py migrate

接下來python manage.py runserver, 訪問http://127.0.0.1:8000 即可看到hello world.

啟動redis

redis是作為celery中間件使用的, 用來存儲消息隊列.

redis解壓后, 直接運行src/redis-server即可啟動, 默認端口6379

配置celery

參考文檔

創建dc/celery.py

#-*- coding:utf-8 -*-import os
from celery import Celery# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'dc.settings')app = Celery('dc')# 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()

修改 dc/__init__.py

from .celery import app as celery_app__all__ = ['celery_app']

修改 dc/settings.py, 設定 redis URL

CELERY_BROKER_URL = 'redis://127.0.0.1:6379/3'

創建dc/main/tasks.py

#-*- coding:utf-8 -*-from celery import shared_task@shared_task
def test():import timetime.sleep(5)from dc.main.models import Personperson = Person(first_name='smith', last_name='jhon')person.save()c = Person.objects.count()print(f'person count is {c}')

修改dc/main/views.py

def hello(request):from dc.main.tasks import testtest.delay()return HttpResponse('hello world')

啟動celery進程

celery -A dc worker -l info

接下來訪問http://127.0.0.1:8000, 即可發現頁面立刻返回, 并沒有被time阻塞, 查看啟動celery的窗口, 即可發現log以及打印的信息, 確定models可以正常使用.

おわり.