Running a task after all tasks have been completed

Question

I\'m writing an application which needs to run a series of tasks in parallel and then a single task with the results of all the tasks run:

@celery.task
def p         


        

Answer 1

Taking a look at this snippet from your question, it looks like you are passing a list as the chord header, rather than a group:

from time import sleep
import random

tasks = []

for i in xrange(10):
    tasks.append(power.s((i, 2)))
    sleep(random.randint(10, 1000) / 1000.0) # sleep for 10-1000ms

callback = amass.s()

r = chord(tasks)(callback)

Converting the list to a group should result in the behaviour you're expecting:

...

callback = amass.s()

tasks = group(tasks)

r = chord(tasks)(callback)