如何使用芹菜按顺序执行独立任务

Question

我必须安排一些看起来非常复杂的任务来并行运行。它们不依赖于彼此的结果，该函数需要 3 个参数。

我已经尝试使用链，地图和星图方法。使用链，我得到此错误：

[2019-04-23 15:28:00,991: ERROR/PoolWorker-3] Task proj.apps.tasks.generate[112a7426-5ac3-4cd6-8416-5591c3c018a3] raised unexpected: TypeError('get expected at least 1 arguments, got 0',)
Traceback (most recent call last):
  File ".../local/lib/python2.7/site-packages/celery/app/trace.py", line 367, in trace_task
    R = retval = fun(*args, **kwargs)
  File ".../local/lib/python2.7/site-packages/celery/app/trace.py", line 622, in __protected_call__
    return self.run(*args, **kwargs)
  File ".../tasks.py", line 966, in generate
    return res.get()
TypeError: get expected at least 1 arguments, got 0

使用map我无法传递所有参数，并且starmap所有任务同时启动。

[2019-04-23 15:48:00,991: INFO/MainProcess] Received task: generate[..]
[2019-04-23 15:48:00,991: INFO/MainProcess] Received task: generate[..]
[2019-04-23 15:48:00,991: INFO/MainProcess] Received task: generate[..]

任务示例：

@shared_task
def generate(field1, field2, field3=None):
   if field3 is not None:
      return field1 + field2 + field3
   return field1 + field2

使用链的代码：

res = chain(generate.s(i, 5, j) for i in array1 for j in array2)
return res.get()

使用星图的代码：

arguments = [(i, 4, j) for i in array1 for j in array2]
~generate.starmap(arguments)

Answer 1

我需要做的就是制作一条链条，如下所示：

res = chain(generate(i, 2, j)for i in array1 for j in array2)()
return res.get()

然后使用设置最大线程数的附加参数运行 Celery

celery -A tasks worker --concurrency=1

Answer 2

如果任务真正独立，你应该使用.si而不是.s：

tasks = chain(generate.si(i, 5, j) for i in array1 for j in array2)
res = tasks()
return res.get()