Celery - Completes task but never returns result

Question

I've just installed Celery and am trying to follow the tutorial:

I have a file called tasks.py with the following code:

from celery import Celery

app = Celery('tasks', backend='amqp', broker='amqp://')

@app.task
def add(x, y):
    return x + y

I installed RabitMQ (I did no configuring with it since the tutorial didn't mention anything of that sort).

I run the celery worker server as follows:

celery -A tasks worker --loglevel=info

It seems to start up normally (here is the output: http://i.imgur.com/qnoNCzJ.png)

Then I run a script with the following:

from tasks import add
from time import sleep

result = add.delay(2,2)

while not result.ready():
    sleep(10)

When I check result.ready() I always get False (so the while loop above runs forever). On the Celery logs, however, everything looks fine:

[2014-10-30 00:58:46,673: INFO/MainProcess] Received task: tasks.add[2bc4ceba-1319-49ce-962d-1ed0a424a2ce]
[2014-10-30 00:58:46,674: INFO/MainProcess] Task tasks.add[2bc4ceba-1319-49ce-962d-1ed0a424a2ce] succeeded in 0.000999927520752s: 4

So the task was recived and succeeds. Yet, result.ready() is still False. Any insight as to why this might be? I am on Windows 7, and am using RabbitMQ. Thanks in advance.

Answer 1

Should solve your problem

ignore_result=False

Answer 2

Okay, I've set up a clear VM with fresh celery install, set the following files:

tasks.py:

from celery import Celery

app = Celery('tasks', backend='amqp', broker='amqp://')

@app.task
def add(x, y):
    return x + y

And runme.py

from tasks import add
import time

result = add.delay(1,2)
while not result.ready():
  time.sleep(1)

print(result.get())

Then I set up celery with:

celery -A tasks worker --loglevel=info

And subsequently I run the runme.py which gives expected result:

[puciek@somewhere tmp]# python3.3 runme.py
3

So clearly the issue is within your setup, most likely somewhere in rabbit-mq installation, so I recommend reinstalling it with latest stable version from sources, which is what I am using, and as you can see - it works just fine.

Update:

Actually, your issue may be as trivial as imaginable - are you sure that you are using same version for celery run, and running your consumer? I just managed to reproduce it, where I've ran celery on Python3.3, and subsequently ran the runme.py with version 2.7. Result was as you've described.