Celery: how to add a callback function when calling a remote task (with send_task)

Question

You can use celery to call a task by name, that is registered in a different process (or even on a different machine):

celery.send_task(task_name, args=args, kwargs=kwargs)

(http://celery.readthedocs.org/en/latest/reference/celery.html#celery.Celery.send_task)

I now would like to be able to add a callback that will be executed as soon as the task finished and that will be executed within the process that is calling the task.

My Setup

I have a server A, that runs a django powered website and I use a basic celery setup as described here. I don't run a celery worker on server A.

Then there is server B, that runs (several) celery worker.

So far, this setup seems to work pretty good. I can send tasks on server A and they get executed on the remote server B.

The Problem

The only problem is, that I'm not able to add a callback function.

In the docs it says, that you can add a callback by providing a follow-up task. So I could do something like this:

@celery.task
def result_handler(result):
    print "YEAH"

celery.send_task(task_name, args=args, kwargs=kwargs, link=result_handler.s())

然而，这意味着，我必须在服务器 A 上启动一个注册任务“result_handler”的工作程序。即使我这样做，处理程序也将在工作人员产生的进程中调用，而不是在调用任务的 django 进程中调用。

我能想出的唯一解决方案是无限循环，每 2 秒检查一次任务是否准备就绪，但我认为应该有一个更简单的解决方案。