This document describes the current stable version of Celery (4.0). For development docs, go here.

Source code for celery.bin.worker

# -*- coding: utf-8 -*-
"""Program used to start a Celery worker instance.

The :program:`celery worker` command (previously known as ``celeryd``)

.. program:: celery worker

.. seealso::

    See :ref:`preload-options`.

.. cmdoption:: -c, --concurrency

    Number of child processes processing the queue.  The default
    is the number of CPUs available on your system.

.. cmdoption:: -P, --pool

    Pool implementation:

    prefork (default), eventlet, gevent or solo.

.. cmdoption:: -n, --hostname

    Set custom hostname (e.g., 'w1@%%h').  Expands: %%h (hostname),
    %%n (name) and %%d, (domain).

.. cmdoption:: -B, --beat

    Also run the `celery beat` periodic task scheduler.  Please note that
    there must only be one instance of this service.

    .. note::

        ``-B`` is meant to be used for development purposes. For production
        environment, you need to start :program:`celery beat` separately.

.. cmdoption:: -Q, --queues

    List of queues to enable for this worker, separated by comma.
    By default all configured queues are enabled.
    Example: `-Q video,image`

.. cmdoption:: -X, --exclude-queues

    List of queues to disable for this worker, separated by comma.
    By default all configured queues are enabled.
    Example: `-X video,image`.

.. cmdoption:: -I, --include

    Comma separated list of additional modules to import.
    Example: -I foo.tasks,bar.tasks

.. cmdoption:: -s, --schedule

    Path to the schedule database if running with the `-B` option.
    Defaults to `celerybeat-schedule`.  The extension ".db" may be
    appended to the filename.

.. cmdoption:: -O

    Apply optimization profile.  Supported: default, fair

.. cmdoption:: --prefetch-multiplier

    Set custom prefetch multiplier value for this worker instance.

.. cmdoption:: --scheduler

    Scheduler class to use.  Default is

.. cmdoption:: -S, --statedb

    Path to the state database.  The extension '.db' may
    be appended to the filename.  Default: {default}

.. cmdoption:: -E, --task-events

    Send task-related events that can be captured by monitors like
    :program:`celery events`, `celerymon`, and others.

.. cmdoption:: --without-gossip

    Don't subscribe to other workers events.

.. cmdoption:: --without-mingle

    Don't synchronize with other workers at start-up.

.. cmdoption:: --without-heartbeat

    Don't send event heartbeats.

.. cmdoption:: --heartbeat-interval

    Interval in seconds at which to send worker heartbeat

.. cmdoption:: --purge

    Purges all waiting tasks before the daemon is started.
    **WARNING**: This is unrecoverable, and the tasks will be
    deleted from the messaging server.

.. cmdoption:: --time-limit

    Enables a hard time limit (in seconds int/float) for tasks.

.. cmdoption:: --soft-time-limit

    Enables a soft time limit (in seconds int/float) for tasks.

.. cmdoption:: --max-tasks-per-child

    Maximum number of tasks a pool worker can execute before it's
    terminated and replaced by a new worker.

.. cmdoption:: --max-memory-per-child

    Maximum amount of resident memory, in KiB, that may be consumed by a
    child process before it will be replaced by a new one.  If a single
    task causes a child process to exceed this limit, the task will be
    completed and the child process will be replaced afterwards.
    Default: no limit.

.. cmdoption:: --autoscale

    Enable autoscaling by providing
    max_concurrency, min_concurrency. Example::


    (always keep 3 processes, but grow to 10 if necessary)

.. cmdoption:: --detach

    Start worker as a background process.

.. cmdoption:: -f, --logfile

    Path to log file.  If no logfile is specified, `stderr` is used.

.. cmdoption:: -l, --loglevel

    Logging level, choose between `DEBUG`, `INFO`, `WARNING`,
    `ERROR`, `CRITICAL`, or `FATAL`.

.. cmdoption:: --pidfile

    Optional file used to store the process pid.

    The program won't start if this file already exists
    and the pid is still alive.

.. cmdoption:: --uid

    User id, or user name of the user to run as after detaching.

.. cmdoption:: --gid

    Group id, or group name of the main group to change to after

.. cmdoption:: --umask

    Effective :manpage:`umask(1)` (in octal) of the process after detaching.
    Inherits the :manpage:`umask(1)` of the parent process by default.

.. cmdoption:: --workdir

    Optional directory to change to after detaching.

.. cmdoption:: --executable

    Executable to use for the detached process.
from __future__ import absolute_import, unicode_literals
import sys
from celery import concurrency
from celery.bin.base import Command, daemon_options
from celery.bin.celeryd_detach import detached_celeryd
from celery.five import string_t
from celery.platforms import maybe_drop_privileges
from celery.utils.log import LOG_LEVELS, mlevel
from celery.utils.nodenames import default_nodename

__all__ = ['worker', 'main']

HELP = __doc__

[docs]class worker(Command): """Start worker instance. Examples: .. code-block:: console $ celery worker --app=proj -l info $ celery worker -A proj -l info -Q hipri,lopri $ celery worker -A proj --concurrency=4 $ celery worker -A proj --concurrency=1000 -P eventlet $ celery worker --autoscale=10,0 """ doc = HELP # parse help from this too namespace = 'worker' enable_config_from_cmdline = True supports_args = False removed_flags = {'--no-execv', '--force-execv'}
[docs] def run_from_argv(self, prog_name, argv=None, command=None): argv = [x for x in argv if x not in self.removed_flags] command = sys.argv[0] if command is None else command argv = sys.argv[1:] if argv is None else argv # parse options before detaching so errors can be handled. options, args = self.prepare_args( *self.parse_options(prog_name, argv, command)) self.maybe_detach([command] + argv) return self(*args, **options)
[docs] def maybe_detach(self, argv, dopts=['-D', '--detach']): if any(arg in argv for arg in dopts): argv = [v for v in argv if v not in dopts] # will never return detached_celeryd( raise SystemExit(0)
[docs] def run(self, hostname=None, pool_cls=None, app=None, uid=None, gid=None, loglevel=None, logfile=None, pidfile=None, statedb=None, **kwargs): maybe_drop_privileges(uid=uid, gid=gid) # Pools like eventlet/gevent needs to patch libs as early # as possible. pool_cls = (concurrency.get_implementation(pool_cls) or if and kwargs.get('beat'): self.die('-B option does not work on Windows. ' 'Please run celery beat as a separate service.') hostname = self.host_format(default_nodename(hostname)) if loglevel: try: loglevel = mlevel(loglevel) except KeyError: # pragma: no cover self.die('Unknown level {0!r}. Please use one of {1}.'.format( loglevel, '|'.join( l for l in LOG_LEVELS if isinstance(l, string_t)))) worker = hostname=hostname, pool_cls=pool_cls, loglevel=loglevel, logfile=logfile, # node format handled by pidfile=self.node_format(pidfile, hostname), statedb=self.node_format(statedb, hostname), **kwargs) worker.start() return worker.exitcode
[docs] def with_pool_option(self, argv): # this command support custom pools # that may have to be loaded as early as possible. return (['-P'], ['--pool'])
[docs] def add_arguments(self, parser): conf = wopts = parser.add_argument_group('Worker Options') wopts.add_argument('-n', '--hostname') wopts.add_argument( '-D', '--detach', action='store_true', default=False, ) wopts.add_argument( '-S', '--statedb', default=conf.worker_state_db, ) wopts.add_argument('-l', '--loglevel', default='WARN') wopts.add_argument('-O', dest='optimization') wopts.add_argument( '--prefetch-multiplier', type=int, default=conf.worker_prefetch_multiplier, ) topts = parser.add_argument_group('Pool Options') topts.add_argument( '-c', '--concurrency', default=conf.worker_concurrency, type=int, ) topts.add_argument( '-P', '--pool', default=conf.worker_pool, ) topts.add_argument( '-E', '--task-events', '--events', action='store_true', default=conf.worker_send_task_events, ) topts.add_argument( '--time-limit', type=float, default=conf.task_time_limit, ) topts.add_argument( '--soft-time-limit', type=float, default=conf.task_soft_time_limit, ) topts.add_argument( '--max-tasks-per-child', '--maxtasksperchild', type=int, default=conf.worker_max_tasks_per_child, ) topts.add_argument( '--max-memory-per-child', '--maxmemperchild', type=int, default=conf.worker_max_memory_per_child, ) qopts = parser.add_argument_group('Queue Options') qopts.add_argument( '--purge', '--discard', action='store_true', default=False, ) qopts.add_argument('--queues', '-Q', default=[]) qopts.add_argument('--exclude-queues', '-X', default=[]) qopts.add_argument('--include', '-I', default=[]) fopts = parser.add_argument_group('Features') fopts.add_argument( '--without-gossip', action='store_true', default=False, ) fopts.add_argument( '--without-mingle', action='store_true', default=False, ) fopts.add_argument( '--without-heartbeat', action='store_true', default=False, ) fopts.add_argument('--heartbeat-interval', type=int) fopts.add_argument('--autoscale') daemon_options(parser) bopts = parser.add_argument_group('Embedded Beat Options') bopts.add_argument('-B', '--beat', action='store_true', default=False) bopts.add_argument( '-s', '--schedule-filename', '--schedule', default=conf.beat_schedule_filename, ) bopts.add_argument('--scheduler') user_options =['worker'] if user_options: uopts = parser.add_argument_group('User Options') self.add_compat_options(uopts, user_options)
[docs]def main(app=None): """Start worker.""" # Fix for setuptools generated scripts, so that it will # work with multiprocessing fork emulation. # (see multiprocessing.forking.get_preparation_data()) if __name__ != '__main__': # pragma: no cover sys.modules['__main__'] = sys.modules[__name__] from billiard import freeze_support freeze_support() worker(app=app).execute_from_commandline()
if __name__ == '__main__': # pragma: no cover main()