This document describes Celery 3.0. For development docs, go here.

Celery Deprecation Timeline

Removals for version 4.0

Old Task API

Compat Task Modules

• Module celery.decorators will be removed:

  Which means you need to change:

  from celery.decorators import task
  

Into:

from celery import task

• Module celery.task may be removed (not decided)

  This means you should change:

  from celery.task import task
  

  into:

  from celery import task
  

  —and::

  from celery.task import Task

  into:

  from celery import Task
  

Note that the new Task class no longer uses classmethods for these methods:

• delay
• apply_async
• retry
• apply
• AsyncResult
• subtask

This also means that you can’t call these methods directly on the class, but have to instantiate the task first:

>>> MyTask.delay()          # NO LONGER WORKS


>>> MyTask().delay()        # WORKS!

TaskSet

TaskSet has been renamed to group and TaskSet will be removed in version 4.0.

Old:

>>> from celery.task import TaskSet

>>> TaskSet(add.subtask((i, i)) for i in xrange(10)).apply_async()

New:

>>> from celery import group
>>> group(add.s(i, i) for i in xrange(10))()

Magic keyword arguments

The magic keyword arguments accepted by tasks will be removed in 4.0, so you should start rewriting any tasks using the celery.decorators module and depending on keyword arguments being passed to the task, for example:

from celery.decorators import task

@task()
def add(x, y, task_id=None):
    print("My task id is %r" % (task_id, ))

must be rewritten into:

from celery import task

@task()
def add(x, y):
    print("My task id is %r" % (add.request.id, ))

Task attributes

The task attributes:

• queue
• exchange
• exchange_type
• routing_key
• delivery_mode
• priority

is deprecated and must be set by CELERY_ROUTES instead.

celery.result

• BaseAsyncResult -> AsyncResult.
• TaskSetResult -> GroupResult.
• TaskSetResult.total -> len(GroupResult)
• TaskSetResult.taskset_id -> GroupResult.id

Apply to: AsyncResult, EagerResult:

- ``Result.wait()`` -> ``Result.get()``

• Result.task_id() -> Result.id
• Result.status -> Result.state.

celery.loader

• current_loader() -> current_app.loader
• load_settings() -> current_app.conf

Modules to Remove

• celery.execute

  This module only contains send_task, which must be replaced with celery.send_task instead.

• celery.decorators

  See Compat Task Modules

• celery.log

  Use celery.log instead.

• celery.messaging

  Use celery.amqp instead.

• celery.registry

  Use celery.app.registry instead.

• celery.task.control

  Use celery.control instead.

• celery.task.schedules

  Use celery.schedules instead.

• celery.task.chords

  Use celery.chord() instead.

Settings

BROKER Settings

Setting name	Replace with
BROKER_HOST	BROKER_URL
BROKER_PORT	BROKER_URL
BROKER_USER	BROKER_URL
BROKER_PASSWORD	BROKER_URL
BROKER_VHOST	BROKER_URL
BROKER_INSIST	no alternative

REDIS Result Backend Settings

Setting name	Replace with
CELERY_REDIS_HOST	CELERY_RESULT_BACKEND
CELERY_REDIS_PORT	CELERY_RESULT_BACKEND
CELERY_REDIS_DB	CELERY_RESULT_BACKEND
CELERY_REDIS_PASSWORD	CELERY_RESULT_BACKEND
REDIS_HOST	CELERY_RESULT_BACKEND
REDIS_PORT	CELERY_RESULT_BACKEND
REDIS_DB	CELERY_RESULT_BACKEND
REDIS_PASSWORD	CELERY_RESULT_BACKEND

Logging Settings

Setting name	Replace with
CELERYD_LOG_LEVEL	--loglevel
CELERYD_LOG_FILE	--logfile`
CELERYBEAT_LOG_LEVEL	--loglevel
CELERYBEAT_LOG_FILE	--loglevel`
CELERYMON_LOG_LEVEL	--loglevel
CELERYMON_LOG_FILE	--loglevel`

Other Settings

Setting name	Replace with
CELERY_TASK_ERROR_WITELIST	Annotate Task.ErrorMail
CELERY_AMQP_TASK_RESULT_EXPIRES	CELERY_TASK_RESULT_EXPIRES

Removals for version 2.0

• The following settings will be removed:

Setting name	Replace with
CELERY_AMQP_CONSUMER_QUEUES	CELERY_QUEUES
CELERY_AMQP_CONSUMER_QUEUES	CELERY_QUEUES
CELERY_AMQP_EXCHANGE	CELERY_DEFAULT_EXCHANGE
CELERY_AMQP_EXCHANGE_TYPE	CELERY_DEFAULT_AMQP_EXCHANGE_TYPE
CELERY_AMQP_CONSUMER_ROUTING_KEY	CELERY_QUEUES
CELERY_AMQP_PUBLISHER_ROUTING_KEY	CELERY_DEFAULT_ROUTING_KEY

• CELERY_LOADER definitions without class name.

  E.g. celery.loaders.default, needs to include the class name: celery.loaders.default.Loader.

• TaskSet.run(). Use celery.task.base.TaskSet.apply_async()

  instead.

• The module celery.task.rest; use celery.task.http instead.