CODEWITHSUNDEEP
djangocelery
Meikelwis Wijaya
Meikelwis Wijaya

Reputation: 95

Execute group task after one group task finished in celery

right now i am implementing celery tasks in my appplication. I want that my task perform chaining But somehow, the chain doesn't work, the group work but the chain doesn't work. The process that I want is I want that the GROUP_A will be processed after i process the GROUP_B and so on. I have tried using chord but still got no idea. Below is my simple chain performing group task in celery. Thank for your attention guys. 

GROUP_A = []

GROUP_B = []

GROUP_C = []

GROUP_D = []


for i in range(3):

    GROUP_A.append(A.s(i+1))
    GROUP_B.append(B.s(i+1))
    GROUP_C.append(C.s(i+1))
    GROUP_D.append(D.s(i+1))

job = chain(

 group(GROUP_A),

 group(GROUP_B),

 group(GROUP_C),

 group(GROUP_D)

)
job.apply_async()

Regards,

Meikelwis Wijaya

Upvotes: 1

Views: 1000

Answers (2)

2ps
2ps

Reputation: 15926

The issue that you have is that you have to get the immutable signature of each group when you pass them up into a subsequent chain because each group is itself a task (and not an invocation of a task):


job = chain(
 group(GROUP_A).si(),
 group(GROUP_B).si(),
 group(GROUP_C).si(),
 group(GROUP_D).si()
)
job.apply_async()

Upvotes: 2

shipperizer
shipperizer

Reputation: 1669

Not sure I understand in full, but when you call tasks with s() they will pass on their results.

In your case for task A you are executing 3 parallel tasks (the group) with nothing passed in, and feeding that to the B task's group.

Not really sure what you are trying to achieve bit if you want just to chain them a simple 

chain([D.si(i, 1), C.s(1), B.s(1), A.s(1)])

Should do, provided that the tasks all accept 2 arguments

Upvotes: 0

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