0、目的
在开发项目中，经常有一些操作时间比较长（生产环境中超过了nginx的timeout时间），或者是间隔一段时间就要执行的任务。
在这种情况下，使用celery就是一个很好的选择。
celery是一个异步任务队列/基于分布式消息传递的作业队列。
Celery通过消息（message）进行通信，使用代理（broker）在客户端和工作执行者之间进行交互。
当开始一个任务时，客户端发送消息到队列并由代理将其发往响应的工作执行者处。
准备使用redis作为消息代理（broker），Django数据库作为结果存储（ResultStore）。
1、安装
redis：
windows：
linux：
yum install redis-server
PS：需要在cmd中运行，不能再powercmd。很奇怪。
pip install celery
pip install celery-with-redis
pip install django-celery
2、django代码（whthas_home为project，portal为app）
修改代码，whthas_home/__init__.py
1 from __future__ import absolute_import 2 3 from .celery import app as celery_app
修改代码，whthas_home/setting.py
1 # Celery settings 2 import djcelery 3 djcelery.setup_loader() 4 5 BROKER_URL = 'redis://127.0.0.1:6379/0' 6 CELERY_RESULT_BACKEND = 'redis://127.0.0.1:6379/0'##加密方式CELERY_RESULT_BACKEND = 'redis://:密码@127.0.0.1:6379/0' 7 CELERY_ACCEPT_CONTENT = ['json'] 8 CELERY_TASK_SERIALIZER = 'json' 9 CELERY_RESULT_SERIALIZER = 'json' 10 CELERYBEAT_SCHEDULER = 'djcelery.schedulers.DatabaseScheduler' 11 CELERY_TIMEZONE = 'Asia/Shanghai' 12 13 # Application definition 14 15 INSTALLED_APPS = [ 16 'django.contrib.auth', 17 'django.contrib.contenttypes', 18 'django.contrib.sessions', 19 'django.contrib.messages', 20 'django.contrib.staticfiles', 21 'suit', 22 'django.contrib.admin', 23 'DjangoUeditor', 24 'portal', 25 'djcelery', 26 ]
增加文件， whthas_home/celery.py
1 from __future__ import absolute_import 2 3 import os 4 from celery import Celery 5 from django.conf import settings 6 7 os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'whthas_home.settings') 8 9 app = Celery('portal') 10 11 app.config_from_object('django.conf:settings') 12 app.autodiscover_tasks(lambda: settings.INSTALLED_APPS) 13 14 15 @app.task(bind=True) 16 def debug_task(self): 17 print('Request: {0!r}'.format(self.request))
增加文件，portal/tasks.py
1 from celery import task 2 from time import sleep 3 4 5 @task() 6 def Task_A(message): 7 Task_A.update_state(state='PROGRESS', meta={'progress': 0}) 8 sleep(10) 9 Task_A.update_state(state='PROGRESS', meta={'progress': 30}) 10 sleep(10) 11 return message 12 13 14 def get_task_status(task_id): 15 task = Task_A.AsyncResult(task_id) 16 17 status = task.state 18 progress = 0 19 20 if status == u'SUCCESS': 21 progress = 100 22 elif status == u'FAILURE': 23 progress = 0 24 elif status == 'PROGRESS': 25 progress = task.info['progress'] 26 27 return {'status': status, 'progress': progress}
3、测试
启动broker：python manage.py celeryd -l info
进入shell：python manage.py shell，测试程序是否正常。
>>> from portal.tasks import * >>> t = TaskA.delay("heel2") >>> get_task_status(t.id) {'status': u'PROGRESS', 'progress': 0} >>> get_task_status(t.id) {'status': u'PROGRESS', 'progress': 0} >>> get_task_status(t.id) {'status': u'PROGRESS', 'progress': 30} >>> get_task_status(t.id) {'status': u'PROGRESS', 'progress': 30} >>> get_task_status(t.id) {'status': u'SUCCESS', 'progress': 100} >>>
同时broker侧能看到：
[2017-04-21 16:38:47,023: INFO/MainProcess] Received task: portal.tasks.Task_A[da948495-c64b-4ff9-882b-876721cd5017]
[2017-04-21 16:39:07,035: INFO/MainProcess] Task portal.tasks.Task_A[da948495-c64b-4ff9-882b-876721cd5017] succeeded in 20.0099999905s: heel
表示代码能正常运行。
使用redis-client看到任务状态：
127.0.0.1:6379> get "celery-task-meta-da948495-c64b-4ff9-882b-876721cd5017"
"{"status": "SUCCESS", "traceback": null, "result": "heel", "children": []}"
相关redis命令：keys *
4、django后台定义任务
进入后台
设置任务
5、执行任务
启动broker：python manage.py celeryd -l info
因为这里是个定时任务，所以还需要启动心跳 ：python manage.py celery beat
broker侧能看到：
[2017-04-21 16:56:33,216: INFO/MainProcess] Received task: portal.tasks.Task_A[d8a26977-8413-4bf0-b518-b53052af4cee] [2017-04-21 16:56:53,211: INFO/MainProcess] Received task: portal.tasks.Task_A[00f1cab7-eb56-4cc3-9979-a8a68aaaf2de] [2017-04-21 16:56:53,220: INFO/MainProcess] Task portal.tasks.Task_A[d8a26977-8413-4bf0-b518-b53052af4cee] succeeded in 20.003000021s: heel2 [2017-04-21 16:57:13,211: INFO/MainProcess] Received task: portal.tasks.Task_A[aa652612-8525-4110-94ea-9010085ec20b] [2017-04-21 16:57:13,223: INFO/MainProcess] Task portal.tasks.Task_A[00f1cab7-eb56-4cc3-9979-a8a68aaaf2de] succeeded in 20.0080001354s: heel2 [2017-04-21 16:57:33,213: INFO/MainProcess] Received task: portal.tasks.Task_A[9876890e-6a71-4501-bdae-775492ebae88] [2017-04-21 16:57:33,219: INFO/MainProcess] Task portal.tasks.Task_A[aa652612-8525-4110-94ea-9010085ec20b] succeeded in 20.0050001144s: heel2 [2017-04-21 16:57:53,211: INFO/MainProcess] Received task: portal.tasks.Task_A[c12fcffc-3910-4a22-93b3-0df740910728] [2017-04-21 16:57:53,221: INFO/MainProcess] Task portal.tasks.Task_A[9876890e-6a71-4501-bdae-775492ebae88] succeeded in 20.0069999695s: heel2 [2017-04-21 16:58:13,211: INFO/MainProcess] Received task: portal.tasks.Task_A[ccfad575-c0b4-48f5-9385-85ff5dac76fc] [2017-04-21 16:58:13,217: INFO/MainProcess] Task portal.tasks.Task_A[c12fcffc-3910-4a22-93b3-0df740910728] succeeded in 20.003000021s: heel2 [2017-04-21 16:58:33,211: INFO/MainProcess] Received task: portal.tasks.Task_A[0d6f77a6-a29c-4ead-9428-e3e758c754e1] [2017-04-21 16:58:33,221: INFO/MainProcess] Task portal.tasks.Task_A[ccfad575-c0b4-48f5-9385-85ff5dac76fc] succeeded in 20.007999897s: heel2 [2017-04-21 16:58:53,211: INFO/MainProcess] Received task: portal.tasks.Task_A[34b2b3a0-771c-4a28-94a1-92e25763fae1] [2017-04-21 16:58:53,217: INFO/MainProcess] Task portal.tasks.Task_A[0d6f77a6-a29c-4ead-9428-e3e758c754e1] succeeded in 20.0039999485s: heel2 [2017-04-21 16:59:13,211: INFO/MainProcess] Received task: portal.tasks.Task_A[d4be920f-376a-46a2-9edd-095234d29ef2] [2017-04-21 16:59:13,217: INFO/MainProcess] Task portal.tasks.Task_A[34b2b3a0-771c-4a28-94a1-92e25763fae1] succeeded in 20.0039999485s: heel2
可见：设置定时任务成功。
参考资料：
1、https://gist.github.com/tyrchen/1436486，Django-celery + Redis notes
2、http://www.cnblogs.com/aguncn/p/4947092.html，django celery redis简单测试
3、https://my.oschina.net/kinegratii/blog/292395?fromerr=2lvw3H0L，djcelery入门：实现运行定时任务