Question

所以我有两个需要并行调用的任务，然后如果他们成功/失败我需要做一些事情，我还需要将他们的结果用于另一个任务。我会在这里试一试白板，试图让它更清晰：

      |                   |
      |                   |
     add               subtract
    /   \               /    \
   /     \             /      \
success   \           /       success
or fail    \         /        or fail
 task       \       /            task
             \     /
              \   /
               \ /
           email results

我认为和弦可能是最好的选择，因为我可以并行执行加法和减法，然后获取结果并执行另一个回调。

以下是我的任务代码：

@shared_task
def add(x):
    print 'adding'
    return x + 5

@shared_task
def subtract(x):
    print 'subtracting'
    return x - 5


@shared_task(ignore_result=True)
def add_subtract_task_success(result):
    if result == 10:
        print 'task_success'

@shared_task
def add_subtract_task_failure(parent_task_id):
    print 'link_error failure'

@shared_task
def email_results(dict):
    print 'This is to be emailed: ' + str(dict)

所以在django shell中玩，我尝试了以下内容：

>>> callback = email_results.s()
>>> header = [add.s(5).apply_async(link=add_subtract_task_success.s(), link_error=add_subtract_task_failure.s()), subtract.s(5).apply_async(link=add_subtract_task_success.s(), link_error=add_subtract_task_failure.s())]
>>> 
>>> result = chord(header)(callback)

这是它产生的例外：

Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/opt/rh/python27/root/usr/lib/python2.7/site-packages/celery-3.1.17-py2.7.egg/celery/canvas.py", line 636, in __call__
return self.apply_async((), {'body': body} if body else {}, **options)
File "/opt/rh/python27/root/usr/lib/python2.7/site-packages/celery-3.1.17-py2.7.egg/celery/canvas.py", line 631, in apply_async
parent = _chord(self.tasks, body, args, **options)
File "/opt/rh/python27/root/usr/lib/python2.7/site-packages/celery-3.1.17-py2.7.egg/celery/app/task.py", line 420, in __call__
return self.run(*args, **kwargs)
File "/opt/rh/python27/root/usr/lib/python2.7/site-packages/celery-3.1.17-py2.7.egg/celery/app/builtins.py", line 329, in run
maybe_signature(s, app=app).clone() for s in tasks
AttributeError: 'AsyncResult' object has no attribute 'clone'

欢迎任何想法和建议，非常感谢。

Celery - 如何在和弦中运行成功和错误回调？

0 个答案: