AttributeError when I'm running Celery worker

Question

I'm trying to use celery for background process in my Django application. Django version is 1.4.8 and latest suitable celery version is 3.1.25.

I use Redis (3.1.0) as broker and backend, json as serializer.

When I start the worker celery -A celery_app worker -l info I'm getting Attribute error 'unicode' object has no attribute 'iteritems'

My settings.py file:

BROKER_URL = 'redis://localhost'
CELERY_RESULT_BACKEND = 'redis://localhost/'
CELERY_ACCEPT_CONTENT = ['json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'
CELERY_STORE_ERRORS_EVEN_IF_IGNORED = True

celery_app.py:

import sys
from django.conf import settings
from celery import Celery

project_root = os.path.dirname(__file__)
sys.path.insert(0, os.path.join(project_root, '../env'))
sys.path.insert(0, os.path.join(project_root, '../'))
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'project.settings')
app = Celery('project')
app.config_from_object('project.settings')
app.autodiscover_tasks(lambda: settings.INSTALLED_APPS, force=True)

tasks.py:

@celery_app.task
def sample_task(x):
    return 'Test response'

and that's how I run this task:

sample_task.delay({'key': 'test'})

And I get the following error:

File "/Users/user/project/venv/lib/python2.7/site-packages/redis/_compat.py", line 94, in iteritems
    return x.iteritems()
AttributeError: 'unicode' object has no attribute 'iteritems'

full traceback:

[2019-01-31 16:43:08,909: ERROR/MainProcess] Unrecoverable error: AttributeError("'unicode' object has no attribute 'iteritems'",)
Traceback (most recent call last):
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/worker/__init__.py", line 206, in start
    self.blueprint.start(self)
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/bootsteps.py", line 123, in start
    step.start(parent)
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/bootsteps.py", line 374, in start
    return self.obj.start()
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/worker/consumer.py", line 280, in start
    blueprint.start(self)
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/bootsteps.py", line 123, in start
    step.start(parent)
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/worker/consumer.py", line 884, in start
    c.loop(*c.loop_args())
  File "/Users/user/project/venv/lib/python2.7/site-packages/celery/worker/loops.py", line 76, in asynloop
    next(loop)
  File "/Users/user/project/venv/lib/python2.7/site-packages/kombu/async/hub.py", line 340, in create_loop
    cb(*cbargs)
  File "/Users/user/project/venv/lib/python2.7/site-packages/kombu/transport/redis.py", line 1019, in on_readable
    self._callbacks[queue](message)
  File "/Users/user/project/venv/lib/python2.7/site-packages/kombu/transport/virtual/__init__.py", line 534, in _callback
    self.qos.append(message, message.delivery_tag)
  File "/Users/user/project/venv/lib/python2.7/site-packages/kombu/transport/redis.py", line 146, in append
    pipe.zadd(self.unacked_index_key, delivery_tag, time()) \
  File "/Users/user/project/venv/lib/python2.7/site-packages/redis/client.py", line 2320, in zadd
    for pair in iteritems(mapping):
  File "/Users/user/project/venv/lib/python2.7/site-packages/redis/_compat.py", line 94, in iteritems
    return x.iteritems()
AttributeError: 'unicode' object has no attribute 'iteritems'

I tried to find the issue on the internet, tried to pass another params to task. I don't know how to debug celery process and could not find the solution by myself. Please help me

Answer 1

Seems that this Celery version doesn't support Redis 3 . Try to install Redis 2.10.6 .