芹菜预定列表返回无 [英] Celery scheduled list returns None

问题描述

我对Celery并不陌生，我一直在尝试设置一个简单的脚本来安排和取消安排任务。但是，我感觉好像遇到了一个奇怪的问题。我有以下设置

I'm fairly new to Celery and I've been attempting setup a simple script to schedule and unschedule tasks. However I feel like I'm running into a weird issue. I have the following setup

from celery import Celery
app = Celery('celery_test',
             broker='amqp://',
             backend='amqp')

@app.task
def add(x, y):
    return x + y

我很好地启动了celery服务器并可以添加任务。现在，当我想获取活动任务列表时，事情似乎变得很奇怪。当我转到使用inspect获取计划任务的列表时，它仅工作一次，然后每次都返回None。

I start up my celery server just fine and can add tasks. Now when I want to get a list of active tasks things seem to get weird. When I goto use inspect to get a list of scheduled tasks it works exactly once then returns None every time afterwards.

>>> i = app.control.inspect()
>>> print i.scheduled()
{u'celery@mymachine': []}
>>> print i.scheduled()
None
>>>

无论我是否添加任务，都会发生这种情况。我想找到一种从西芹队列中连续返回任务列表的方法。我想这样做，以便可以找到先前排队的任务，将其吊销，然后重新计划。我觉得这里缺少基本的东西。

This happens whether I add tasks or not. I want to find a way to consistently return a list of tasks from my celery queue. I want to do this so I can find a previously queued task, revoke it, and reschedule it. I feel like I'm missing something basic here.

推荐答案

要重复调用以获取队列中必须创建的任务列表Celery对象的新实例。我试图通过调用 ./ manage.py celery inspect schedule 调试执行的代码来弄清楚为什么有必要，但是没有任何运气。也许有人会对此有更多的经验，并在此答案中添加一些其他信息。

To repeat call to get list of tasks in queues you have to create new instance of Celery object. I was trying to figure out why it's necessary by debugging code executed by calling ./manage.py celery inspect scheduled but without any luck. Maybe someone will have more experience with that and add some additional informations to this answer.

尝试使用以下简单代码段检查计划任务列表：

Try this simple snippet for checking list of scheduled tasks:

from celery import Celery

def inspect(method):
    app = Celery('app', broker='amqp://')
    return getattr(app.control.inspect(), method)()

print inspect('scheduled')
print inspect('active')

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