摘要：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則可以不阻塞請求后臺處理這些任務并且可以使用的進行數據庫操作環境其他創建工程此時項目結構如下修改添加修改創建新創

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.

python models:

celery-4.1.1

redis-2.10.6

django-1.11.7

其他:

redis-3.2.9

macos

python3.6

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.

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

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 time
    time.sleep(5)
    from dc.main.models import Person
    person = 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 test
    test.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.