.. _configuration: ============================ Configuration and defaults ============================ This document describes the configuration options available. If you're using the default loader, you must create the :file:`celeryconfig.py` module and make sure it is available on the Python path. .. contents:: :local: :depth: 2 .. _conf-example: Example configuration file ========================== This is an example configuration file to get you started. It should contain all you need to run a basic Celery set-up. .. code-block:: python # List of modules to import when celery starts. CELERY_IMPORTS = ("myapp.tasks", ) ## Result store settings. CELERY_RESULT_BACKEND = "database" CELERY_RESULT_DBURI = "sqlite:///mydatabase.db" ## Broker settings. BROKER_URL = "amqp://guest:guest@localhost:5672//" ## Worker settings ## If you're doing mostly I/O you can have more processes, ## but if mostly spending CPU, try to keep it close to the ## number of CPUs on your machine. If not set, the number of CPUs/cores ## available will be used. CELERYD_CONCURRENCY = 10 Configuration Directives ======================== .. _conf-concurrency: Concurrency settings -------------------- .. setting:: CELERYD_CONCURRENCY CELERYD_CONCURRENCY ~~~~~~~~~~~~~~~~~~~ The number of concurrent worker processes/threads/green threads, executing tasks. Defaults to the number of available CPUs. .. setting:: CELERYD_PREFETCH_MULTIPLIER CELERYD_PREFETCH_MULTIPLIER ~~~~~~~~~~~~~~~~~~~~~~~~~~~ How many messages to prefetch at a time multiplied by the number of concurrent processes. The default is 4 (four messages for each process). The default setting is usually a good choice, however -- if you have very long running tasks waiting in the queue and you have to start the workers, note that the first worker to start will receive four times the number of messages initially. Thus the tasks may not be fairly distributed to the workers. .. _conf-result-backend: Task result backend settings ---------------------------- .. setting:: CELERY_RESULT_BACKEND CELERY_RESULT_BACKEND ~~~~~~~~~~~~~~~~~~~~~ :Deprecated aliases: ``CELERY_BACKEND`` The backend used to store task results (tombstones). Disabled by default. Can be one of the following: * database Use a relational database supported by `SQLAlchemy`_. See :ref:`conf-database-result-backend`. * cache Use `memcached`_ to store the results. See :ref:`conf-cache-result-backend`. * mongodb Use `MongoDB`_ to store the results. See :ref:`conf-mongodb-result-backend`. * redis Use `Redis`_ to store the results. See :ref:`conf-redis-result-backend`. * tyrant Use `Tokyo Tyrant`_ to store the results. See :ref:`conf-tyrant-result-backend`. * amqp Send results back as AMQP messages See :ref:`conf-amqp-result-backend`. .. warning: While the AMQP result backend is very efficient, you must make sure you only receive the same result once. See :doc:`userguide/executing`). .. _`SQLAlchemy`: http://sqlalchemy.org .. _`memcached`: http://memcached.org .. _`MongoDB`: http://mongodb.org .. _`Redis`: http://code.google.com/p/redis/ .. _`Tokyo Tyrant`: http://1978th.net/tokyotyrant/ .. setting:: CELERY_RESULT_SERIALIZER CELERY_RESULT_SERIALIZER ~~~~~~~~~~~~~~~~~~~~~~~~ Result serialization format. Default is `"pickle"`. See :ref:`executing-serializers` for information about supported serialization formats. .. _conf-database-result-backend: Database backend settings ------------------------- .. setting:: CELERY_RESULT_DBURI CELERY_RESULT_DBURI ~~~~~~~~~~~~~~~~~~~ Please see `Supported Databases`_ for a table of supported databases. To use this backend you need to configure it with an `Connection String`_, some examples include: .. code-block:: python # sqlite (filename) CELERY_RESULT_DBURI = "sqlite:///celerydb.sqlite" # mysql CELERY_RESULT_DBURI = "mysql://scott:tiger@localhost/foo" # postgresql CELERY_RESULT_DBURI = "postgresql://scott:tiger@localhost/mydatabase" # oracle CELERY_RESULT_DBURI = "oracle://scott:tiger@127.0.0.1:1521/sidname" See `Connection String`_ for more information about connection strings. .. setting:: CELERY_RESULT_ENGINE_OPTIONS CELERY_RESULT_ENGINE_OPTIONS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To specify additional SQLAlchemy database engine options you can use the :setting:`CELERY_RESULT_ENGINE_OPTIONS` setting:: # echo enables verbose logging from SQLAlchemy. CELERY_RESULT_ENGINE_OPTIONS = {"echo": True} .. setting:: CELERY_RESULT_DB_SHORT_LIVED_SESSIONS CELERY_RESULT_DB_SHORT_LIVED_SESSIONS = True Short lived sessions are disabled by default. If enabled they can drastically reduce performance, especially on systems processing lots of tasks. This option is useful on low-traffic workers that experience errors as a result of cached database connections going stale through inactivity. For example, intermittent errors like `(OperationalError) (2006, 'MySQL server has gone away')` can be fixed by enabling short lived sessions. This option only affects the database backend. .. _`Supported Databases`: http://www.sqlalchemy.org/docs/core/engines.html#supported-databases .. _`Connection String`: http://www.sqlalchemy.org/docs/core/engines.html#database-urls Example configuration ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: python CELERY_RESULT_BACKEND = "database" CELERY_RESULT_DBURI = "mysql://user:password@host/dbname" .. _conf-amqp-result-backend: AMQP backend settings --------------------- .. note:: The AMQP backend requires RabbitMQ 1.1.0 or higher to automatically expire results. If you are running an older version of RabbitmQ you should disable result expiration like this: CELERY_TASK_RESULT_EXPIRES = None .. setting:: CELERY_RESULT_EXCHANGE CELERY_RESULT_EXCHANGE ~~~~~~~~~~~~~~~~~~~~~~ Name of the exchange to publish results in. Default is `"celeryresults"`. .. setting:: CELERY_RESULT_EXCHANGE_TYPE CELERY_RESULT_EXCHANGE_TYPE ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The exchange type of the result exchange. Default is to use a `direct` exchange. .. setting:: CELERY_RESULT_PERSISTENT CELERY_RESULT_PERSISTENT ~~~~~~~~~~~~~~~~~~~~~~~~ If set to :const:`True`, result messages will be persistent. This means the messages will not be lost after a broker restart. The default is for the results to be transient. Example configuration ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: python CELERY_RESULT_BACKEND = "amqp" CELERY_TASK_RESULT_EXPIRES = 18000 # 5 hours. .. _conf-cache-result-backend: Cache backend settings ---------------------- .. note:: The cache backend supports the `pylibmc`_ and `python-memcached` libraries. The latter is used only if `pylibmc`_ is not installed. .. setting:: CELERY_CACHE_BACKEND CELERY_CACHE_BACKEND ~~~~~~~~~~~~~~~~~~~~ Using a single memcached server: .. code-block:: python CELERY_CACHE_BACKEND = 'memcached://127.0.0.1:11211/' Using multiple memcached servers: .. code-block:: python CELERY_RESULT_BACKEND = "cache" CELERY_CACHE_BACKEND = 'memcached://172.19.26.240:11211;172.19.26.242:11211/' .. setting:: CELERY_CACHE_BACKEND_OPTIONS The "dummy" backend stores the cache in memory only: CELERY_CACHE_BACKEND = "dummy" CELERY_CACHE_BACKEND_OPTIONS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can set pylibmc options using the :setting:`CELERY_CACHE_BACKEND_OPTIONS` setting: .. code-block:: python CELERY_CACHE_BACKEND_OPTIONS = {"binary": True, "behaviors": {"tcp_nodelay": True}} .. _`pylibmc`: http://sendapatch.se/projects/pylibmc/ .. _conf-tyrant-result-backend: Tokyo Tyrant backend settings ----------------------------- .. note:: The Tokyo Tyrant backend requires the :mod:`pytyrant` library: http://pypi.python.org/pypi/pytyrant/ This backend requires the following configuration directives to be set: .. setting:: TT_HOST TT_HOST ~~~~~~~ Host name of the Tokyo Tyrant server. .. setting:: TT_PORT TT_PORT ~~~~~~~ The port the Tokyo Tyrant server is listening to. Example configuration ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: python CELERY_RESULT_BACKEND = "tyrant" TT_HOST = "localhost" TT_PORT = 1978 .. _conf-redis-result-backend: Redis backend settings ---------------------- .. note:: The Redis backend requires the :mod:`redis` library: http://pypi.python.org/pypi/redis/ To install the redis package use `pip` or `easy_install`:: $ pip install redis This backend requires the following configuration directives to be set. .. setting:: CELERY_REDIS_HOST CELERY_REDIS_HOST ~~~~~~~~~~~~~~~~~ Host name of the Redis database server. e.g. `"localhost"`. .. setting:: CELERY_REDIS_PORT CELERY_REDIS_PORT ~~~~~~~~~~~~~~~~~ Port to the Redis database server. e.g. `6379`. .. setting:: CELERY_REDIS_DB CELERY_REDIS_DB ~~~~~~~~~~~~~~~ Database number to use. Default is 0 .. setting:: CELERY_REDIS_PASSWORD CELERY_REDIS_PASSWORD ~~~~~~~~~~~~~~~~~~~~~ Password used to connect to the database. Example configuration ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: python CELERY_RESULT_BACKEND = "redis" CELERY_REDIS_HOST = "localhost" CELERY_REDIS_PORT = 6379 CELERY_REDIS_DB = 0 .. _conf-mongodb-result-backend: MongoDB backend settings ------------------------ .. note:: The MongoDB backend requires the :mod:`pymongo` library: http://github.com/mongodb/mongo-python-driver/tree/master .. setting:: CELERY_MONGODB_BACKEND_SETTINGS CELERY_MONGODB_BACKEND_SETTINGS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is a dict supporting the following keys: * host Host name of the MongoDB server. Defaults to "localhost". * port The port the MongoDB server is listening to. Defaults to 27017. * user User name to authenticate to the MongoDB server as (optional). * password Password to authenticate to the MongoDB server (optional). * database The database name to connect to. Defaults to "celery". * taskmeta_collection The collection name to store task meta data. Defaults to "celery_taskmeta". .. _example-mongodb-result-config: Example configuration ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: python CELERY_RESULT_BACKEND = "mongodb" CELERY_MONGODB_BACKEND_SETTINGS = { "host": "192.168.1.100", "port": 30000, "database": "mydb", "taskmeta_collection": "my_taskmeta_collection", } .. _conf-messaging: Message Routing --------------- .. _conf-messaging-routing: .. setting:: CELERY_QUEUES CELERY_QUEUES ~~~~~~~~~~~~~ The mapping of queues the worker consumes from. This is a dictionary of queue name/options. See :ref:`guide-routing` for more information. The default is a queue/exchange/binding key of `"celery"`, with exchange type `direct`. You don't have to care about this unless you want custom routing facilities. .. setting:: CELERY_ROUTES CELERY_ROUTES ~~~~~~~~~~~~~ A list of routers, or a single router used to route tasks to queues. When deciding the final destination of a task the routers are consulted in order. See :ref:`routers` for more information. .. setting:: CELERY_CREATE_MISSING_QUEUES CELERY_CREATE_MISSING_QUEUES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If enabled (default), any queues specified that is not defined in :setting:`CELERY_QUEUES` will be automatically created. See :ref:`routing-automatic`. .. setting:: CELERY_DEFAULT_QUEUE CELERY_DEFAULT_QUEUE ~~~~~~~~~~~~~~~~~~~~ The queue used by default, if no custom queue is specified. This queue must be listed in :setting:`CELERY_QUEUES`. The default is: `celery`. .. seealso:: :ref:`routing-changing-default-queue` .. setting:: CELERY_DEFAULT_EXCHANGE CELERY_DEFAULT_EXCHANGE ~~~~~~~~~~~~~~~~~~~~~~~ Name of the default exchange to use when no custom exchange is specified. The default is: `celery`. .. setting:: CELERY_DEFAULT_EXCHANGE_TYPE CELERY_DEFAULT_EXCHANGE_TYPE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Default exchange type used when no custom exchange is specified. The default is: `direct`. .. setting:: CELERY_DEFAULT_ROUTING_KEY CELERY_DEFAULT_ROUTING_KEY ~~~~~~~~~~~~~~~~~~~~~~~~~~ The default routing key used when sending tasks. The default is: `celery`. .. setting:: CELERY_DEFAULT_DELIVERY_MODE CELERY_DEFAULT_DELIVERY_MODE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Can be `transient` or `persistent`. The default is to send persistent messages. .. _conf-broker-settings: Broker Settings --------------- .. setting:: BROKER_TRANSPORT BROKER_TRANSPORT ~~~~~~~~~~~~~~~~ :Aliases: ``BROKER_BACKEND`` :Deprecated aliases: ``CARROT_BACKEND`` The Kombu transport to use. Default is ``amqplib``. You can use a custom transport class name, or select one of the built-in transports: ``amqplib``, ``pika``, ``redis``, ``beanstalk``, ``sqlalchemy``, ``django``, ``mongodb``, ``couchdb``. .. setting:: BROKER_URL BROKER_URL ~~~~~~~~~~ Default broker URL. This must be an URL in the form of:: transport://userid:password@hostname:port/virtual_host Only the scheme part (``transport://``) is required, the rest is optional, and defaults to the specific transports default values. If this setting is defined it will override a subset of the other ``BROKER`` options. These options are :setting:`BROKER_HOST`, :setting:`BROKER_USER`, :setting:`BROKER_PASSWORD`, :setting:`BROKER_PORT`, and :setting:`BROKER_VHOST`. See the Kombu documentation for more information about broker URLs. .. setting:: BROKER_HOST BROKER_HOST ~~~~~~~~~~~ Hostname of the broker. .. setting:: BROKER_PORT BROKER_PORT ~~~~~~~~~~~ Custom port of the broker. Default is to use the default port for the selected backend. .. setting:: BROKER_USER BROKER_USER ~~~~~~~~~~~ Username to connect as. .. setting:: BROKER_PASSWORD BROKER_PASSWORD ~~~~~~~~~~~~~~~ Password to connect with. .. setting:: BROKER_VHOST BROKER_VHOST ~~~~~~~~~~~~ Virtual host. Default is `"/"`. .. setting:: BROKER_USE_SSL BROKER_USE_SSL ~~~~~~~~~~~~~~ Use SSL to connect to the broker. Off by default. This may not be supported by all transports. .. setting:: BROKER_POOL_LIMIT BROKER_POOL_LIMIT ~~~~~~~~~~~~~~~~~ .. versionadded:: 2.3 The maximum number of connections that can be open in the connection pool. A good default value could be 10, or more if you're using eventlet/gevent or lots of threads. If set to :const:`None` or 0 the connection pool will be disabled and connections will be established and closed for every use. **Disabled by default.** .. setting:: BROKER_CONNECTION_TIMEOUT BROKER_CONNECTION_TIMEOUT ~~~~~~~~~~~~~~~~~~~~~~~~~ The default timeout in seconds before we give up establishing a connection to the AMQP server. Default is 4 seconds. .. setting:: BROKER_CONNECTION_RETRY BROKER_CONNECTION_RETRY ~~~~~~~~~~~~~~~~~~~~~~~ Automatically try to re-establish the connection to the AMQP broker if lost. The time between retries is increased for each retry, and is not exhausted before :setting:`BROKER_CONNECTION_MAX_RETRIES` is exceeded. This behavior is on by default. .. setting:: BROKER_CONNECTION_MAX_RETRIES BROKER_CONNECTION_MAX_RETRIES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Maximum number of retries before we give up re-establishing a connection to the AMQP broker. If this is set to :const:`0` or :const:`None`, we will retry forever. Default is 100 retries. .. setting:: BROKER_TRANSPORT_OPTIONS BROKER_TRANSPORT_OPTIONS ~~~~~~~~~~~~~~~~~~~~~~~~ .. versionadded:: 2.2 A dict of additional options passed to the underlying transport. See your transport user manual for supported options (if any). .. _conf-task-execution: Task execution settings ----------------------- .. setting:: CELERY_ALWAYS_EAGER CELERY_ALWAYS_EAGER ~~~~~~~~~~~~~~~~~~~ If this is :const:`True`, all tasks will be executed locally by blocking until the task returns. ``apply_async()`` and ``Task.delay()`` will return an :class:`~celery.result.EagerResult` instance, which emulates the API and behavior of :class:`~celery.result.AsyncResult`, except the result is already evaluated. That is, tasks will be executed locally instead of being sent to the queue. .. setting:: CELERY_EAGER_PROPAGATES_EXCEPTIONS CELERY_EAGER_PROPAGATES_EXCEPTIONS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If this is :const:`True`, eagerly executed tasks (applied by `task.apply()`, or when the :setting:`CELERY_ALWAYS_EAGER` setting is enabled), will propagate exceptions. It's the same as always running ``apply()`` with ``throw=True``. .. setting:: CELERY_IGNORE_RESULT CELERY_IGNORE_RESULT ~~~~~~~~~~~~~~~~~~~~ Whether to store the task return values or not (tombstones). If you still want to store errors, just not successful return values, you can set :setting:`CELERY_STORE_ERRORS_EVEN_IF_IGNORED`. .. setting:: CELERY_MESSAGE_COMPRESSION CELERY_MESSAGE_COMPRESSION ~~~~~~~~~~~~~~~~~~~~~~~~~~ Default compression used for task messages. Can be ``"gzip"``, ``"bzip2"`` (if available), or any custom compression schemes registered in the Kombu compression registry. The default is to send uncompressed messages. .. setting:: CELERY_TASK_RESULT_EXPIRES CELERY_TASK_RESULT_EXPIRES ~~~~~~~~~~~~~~~~~~~~~~~~~~ Time (in seconds, or a :class:`~datetime.timedelta` object) for when after stored task tombstones will be deleted. A built-in periodic task will delete the results after this time (:class:`celery.task.backend_cleanup`). .. note:: For the moment this only works with the amqp, database, cache, redis and MongoDB backends. When using the database or MongoDB backends, `celerybeat` must be running for the results to be expired. .. setting:: CELERY_MAX_CACHED_RESULTS CELERY_MAX_CACHED_RESULTS ~~~~~~~~~~~~~~~~~~~~~~~~~ Result backends caches ready results used by the client. This is the total number of results to cache before older results are evicted. The default is 5000. .. setting:: CELERY_TRACK_STARTED CELERY_TRACK_STARTED ~~~~~~~~~~~~~~~~~~~~ If :const:`True` the task will report its status as "started" when the task is executed by a worker. The default value is :const:`False` as the normal behaviour is to not report that level of granularity. Tasks are either pending, finished, or waiting to be retried. Having a "started" state can be useful for when there are long running tasks and there is a need to report which task is currently running. .. setting:: CELERY_TASK_SERIALIZER CELERY_TASK_SERIALIZER ~~~~~~~~~~~~~~~~~~~~~~ A string identifying the default serialization method to use. Can be `pickle` (default), `json`, `yaml`, `msgpack` or any custom serialization methods that have been registered with :mod:`kombu.serialization.registry`. .. seealso:: :ref:`executing-serializers`. .. setting:: CELERY_TASK_PUBLISH_RETRY CELERY_TASK_PUBLISH_RETRY ~~~~~~~~~~~~~~~~~~~~~~~~~ .. versionadded:: 2.2 Decides if publishing task messages will be retried in the case of connection loss or other connection errors. See also :setting:`CELERY_TASK_PUBLISH_RETRY_POLICY`. Disabled by default. .. setting:: CELERY_TASK_PUBLISH_RETRY_POLICY CELERY_TASK_PUBLISH_RETRY_POLICY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. versionadded:: 2.2 Defines the default policy when retrying publishing a task message in the case of connection loss or other connection errors. This is a mapping that must contain the following keys: * `max_retries` Maximum number of retries before giving up, in this case the exception that caused the retry to fail will be raised. A value of 0 or :const:`None` means it will retry forever. The default is to retry 3 times. * `interval_start` Defines the number of seconds (float or integer) to wait between retries. Default is 0, which means the first retry will be instantaneous. * `interval_step` On each consecutive retry this number will be added to the retry delay (float or integer). Default is 0.2. * `interval_max` Maximum number of seconds (float or integer) to wait between retries. Default is 0.2. With the default policy of:: {"max_retries": 3, "interval_start": 0, "interval_step": 0.2, "interval_max": 0.2} the maximum time spent retrying will be 0.4 seconds. It is set relatively short by default because a connection failure could lead to a retry pile effect if the broker connection is down: e.g. many web server processes waiting to retry blocking other incoming requests. .. setting:: CELERY_DEFAULT_RATE_LIMIT CELERY_DEFAULT_RATE_LIMIT ~~~~~~~~~~~~~~~~~~~~~~~~~ The global default rate limit for tasks. This value is used for tasks that does not have a custom rate limit The default is no rate limit. .. setting:: CELERY_DISABLE_RATE_LIMITS CELERY_DISABLE_RATE_LIMITS ~~~~~~~~~~~~~~~~~~~~~~~~~~ Disable all rate limits, even if tasks has explicit rate limits set. .. setting:: CELERY_ACKS_LATE CELERY_ACKS_LATE ~~~~~~~~~~~~~~~~ Late ack means the task messages will be acknowledged **after** the task has been executed, not *just before*, which is the default behavior. .. seealso:: FAQ: :ref:`faq-acks_late-vs-retry`. .. _conf-celeryd: Worker: celeryd --------------- .. setting:: CELERY_IMPORTS CELERY_IMPORTS ~~~~~~~~~~~~~~ A sequence of modules to import when the celery daemon starts. This is used to specify the task modules to import, but also to import signal handlers and additional remote control commands, etc. .. setting:: CELERYD_MAX_TASKS_PER_CHILD CELERYD_MAX_TASKS_PER_CHILD ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Maximum number of tasks a pool worker process can execute before it's replaced with a new one. Default is no limit. .. setting:: CELERYD_TASK_TIME_LIMIT CELERYD_TASK_TIME_LIMIT ~~~~~~~~~~~~~~~~~~~~~~~ Task hard time limit in seconds. The worker processing the task will be killed and replaced with a new one when this is exceeded. .. setting:: CELERYD_TASK_SOFT_TIME_LIMIT CELERYD_TASK_SOFT_TIME_LIMIT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Task soft time limit in seconds. The :exc:`~celery.exceptions.SoftTimeLimitExceeded` exception will be raised when this is exceeded. The task can catch this to e.g. clean up before the hard time limit comes. Example: .. code-block:: python from celery.task import task from celery.exceptions import SoftTimeLimitExceeded @task() def mytask(): try: return do_work() except SoftTimeLimitExceeded: cleanup_in_a_hurry() .. setting:: CELERY_STORE_ERRORS_EVEN_IF_IGNORED CELERY_STORE_ERRORS_EVEN_IF_IGNORED ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If set, the worker stores all task errors in the result store even if :attr:`Task.ignore_result ` is on. .. setting:: CELERYD_STATE_DB CELERYD_STATE_DB ~~~~~~~~~~~~~~~~ Name of the file used to stores persistent worker state (like revoked tasks). Can be a relative or absolute path, but be aware that the suffix `.db` may be appended to the file name (depending on Python version). Can also be set via the :option:`--statedb` argument to :mod:`~celery.bin.celeryd`. Not enabled by default. .. setting:: CELERYD_ETA_SCHEDULER_PRECISION CELERYD_ETA_SCHEDULER_PRECISION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Set the maximum time in seconds that the ETA scheduler can sleep between rechecking the schedule. Default is 1 second. Setting this value to 1 second means the schedulers precision will be 1 second. If you need near millisecond precision you can set this to 0.1. .. _conf-error-mails: Error E-Mails ------------- .. setting:: CELERY_SEND_TASK_ERROR_EMAILS CELERY_SEND_TASK_ERROR_EMAILS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The default value for the `Task.send_error_emails` attribute, which if set to :const:`True` means errors occurring during task execution will be sent to :setting:`ADMINS` by email. .. setting:: ADMINS ADMINS ~~~~~~ List of `(name, email_address)` tuples for the administrators that should receive error emails. .. setting:: SERVER_EMAIL SERVER_EMAIL ~~~~~~~~~~~~ The email address this worker sends emails from. Default is celery@localhost. .. setting:: EMAIL_HOST EMAIL_HOST ~~~~~~~~~~ The mail server to use. Default is `"localhost"`. .. setting:: EMAIL_HOST_USER EMAIL_HOST_USER ~~~~~~~~~~~~~~~ User name (if required) to log on to the mail server with. .. setting:: EMAIL_HOST_PASSWORD EMAIL_HOST_PASSWORD ~~~~~~~~~~~~~~~~~~~ Password (if required) to log on to the mail server with. .. setting:: EMAIL_PORT EMAIL_PORT ~~~~~~~~~~ The port the mail server is listening on. Default is `25`. .. setting:: EMAIL_USE_SSL EMAIL_USE_SSL ~~~~~~~~~~~~~ Use SSL when connecting to the SMTP server. Disabled by default. .. setting:: EMAIL_USE_TLS EMAIL_USE_TLS ~~~~~~~~~~~~~ Use TLS when connecting to the SMTP server. Disabled by default. .. setting:: EMAIL_TIMEOUT EMAIL_TIMEOUT ~~~~~~~~~~~~~ Timeout in seconds for when we give up trying to connect to the SMTP server when sending emails. The default is 2 seconds. .. _conf-example-error-mail-config: Example E-Mail configuration ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This configuration enables the sending of error emails to george@vandelay.com and kramer@vandelay.com: .. code-block:: python # Enables error emails. CELERY_SEND_TASK_ERROR_EMAILS = True # Name and email addresses of recipients ADMINS = ( ("George Costanza", "george@vandelay.com"), ("Cosmo Kramer", "kosmo@vandelay.com"), ) # Email address used as sender (From field). SERVER_EMAIL = "no-reply@vandelay.com" # Mailserver configuration EMAIL_HOST = "mail.vandelay.com" EMAIL_PORT = 25 # EMAIL_HOST_USER = "servers" # EMAIL_HOST_PASSWORD = "s3cr3t" .. _conf-events: Events ------ .. setting:: CELERY_SEND_EVENTS CELERY_SEND_EVENTS ~~~~~~~~~~~~~~~~~~ Send events so the worker can be monitored by tools like `celerymon`. .. setting:: CELERY_SEND_TASK_SENT_EVENT CELERY_SEND_TASK_SENT_EVENT ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. versionadded:: 2.2 If enabled, a `task-sent` event will be sent for every task so tasks can be tracked before they are consumed by a worker. Disabled by default. .. setting:: CELERY_EVENT_SERIALIZER CELERY_EVENT_SERIALIZER ~~~~~~~~~~~~~~~~~~~~~~~ Message serialization format used when sending event messages. Default is `"json"`. See :ref:`executing-serializers`. .. _conf-broadcast: Broadcast Commands ------------------ .. setting:: CELERY_BROADCAST_QUEUE CELERY_BROADCAST_QUEUE ~~~~~~~~~~~~~~~~~~~~~~ Name prefix for the queue used when listening for broadcast messages. The workers host name will be appended to the prefix to create the final queue name. Default is `"celeryctl"`. .. setting:: CELERY_BROADCAST_EXCHANGE CELERY_BROADCAST_EXCHANGE ~~~~~~~~~~~~~~~~~~~~~~~~~ Name of the exchange used for broadcast messages. Default is `"celeryctl"`. .. setting:: CELERY_BROADCAST_EXCHANGE_TYPE CELERY_BROADCAST_EXCHANGE_TYPE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Exchange type used for broadcast messages. Default is `"fanout"`. .. _conf-logging: Logging ------- .. setting:: CELERYD_HIJACK_ROOT_LOGGER CELERYD_HIJACK_ROOT_LOGGER ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. versionadded:: 2.2 By default any previously configured logging options will be reset, because the Celery programs "hijacks" the root logger. If you want to customize your own logging then you can disable this behavior. .. note:: Logging can also be customized by connecting to the :signal:`celery.signals.setup_logging` signal. .. setting:: CELERYD_LOG_COLOR CELERYD_LOG_COLOR ~~~~~~~~~~~~~~~~~ Enables/disables colors in logging output by the Celery apps. By default colors are enabled if 1) the app is logging to a real terminal, and not a file. 2) the app is not running on Windows. .. setting:: CELERYD_LOG_FORMAT CELERYD_LOG_FORMAT ~~~~~~~~~~~~~~~~~~ The format to use for log messages. Default is `[%(asctime)s: %(levelname)s/%(processName)s] %(message)s` See the Python :mod:`logging` module for more information about log formats. .. setting:: CELERYD_TASK_LOG_FORMAT CELERYD_TASK_LOG_FORMAT ~~~~~~~~~~~~~~~~~~~~~~~ The format to use for log messages logged in tasks. Can be overridden using the :option:`--loglevel` option to :mod:`~celery.bin.celeryd`. Default is:: [%(asctime)s: %(levelname)s/%(processName)s] [%(task_name)s(%(task_id)s)] %(message)s See the Python :mod:`logging` module for more information about log formats. .. setting:: CELERY_REDIRECT_STDOUTS CELERY_REDIRECT_STDOUTS ~~~~~~~~~~~~~~~~~~~~~~~ If enabled `stdout` and `stderr` will be redirected to the current logger. Enabled by default. Used by :program:`celeryd` and :program:`celerybeat`. .. setting:: CELERY_REDIRECT_STDOUTS_LEVEL CELERY_REDIRECT_STDOUTS_LEVEL ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The log level output to `stdout` and `stderr` is logged as. Can be one of :const:`DEBUG`, :const:`INFO`, :const:`WARNING`, :const:`ERROR` or :const:`CRITICAL`. Default is :const:`WARNING`. .. _conf-custom-components: Custom Component Classes (advanced) ----------------------------------- .. setting:: CELERYD_POOL CELERYD_POOL ~~~~~~~~~~~~ Name of the pool class used by the worker. You can use a custom pool class name, or select one of the built-in aliases: ``processes``, ``eventlet``, ``gevent``. Default is ``processes``. .. setting:: CELERYD_AUTOSCALER CELERYD_AUTOSCALER ~~~~~~~~~~~~~~~~~~ .. versionadded:: 2.2 Name of the autoscaler class to use. Default is ``"celery.worker.autoscale.Autoscaler"``. .. setting:: CELERYD_CONSUMER CELERYD_CONSUMER ~~~~~~~~~~~~~~~~ Name of the consumer class used by the worker. Default is :class:`celery.worker.consumer.Consumer` .. setting:: CELERYD_MEDIATOR CELERYD_MEDIATOR ~~~~~~~~~~~~~~~~ Name of the mediator class used by the worker. Default is :class:`celery.worker.controllers.Mediator`. .. setting:: CELERYD_ETA_SCHEDULER CELERYD_ETA_SCHEDULER ~~~~~~~~~~~~~~~~~~~~~ Name of the ETA scheduler class used by the worker. Default is :class:`celery.utils.timer2.Timer`, or one overrided by the pool implementation. .. _conf-celerybeat: Periodic Task Server: celerybeat -------------------------------- .. setting:: CELERYBEAT_SCHEDULE CELERYBEAT_SCHEDULE ~~~~~~~~~~~~~~~~~~~ The periodic task schedule used by :mod:`~celery.bin.celerybeat`. See :ref:`beat-entries`. .. setting:: CELERYBEAT_SCHEDULER CELERYBEAT_SCHEDULER ~~~~~~~~~~~~~~~~~~~~ The default scheduler class. Default is `"celery.beat.PersistentScheduler"`. Can also be set via the :option:`-S` argument to :mod:`~celery.bin.celerybeat`. .. setting:: CELERYBEAT_SCHEDULE_FILENAME CELERYBEAT_SCHEDULE_FILENAME ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Name of the file used by `PersistentScheduler` to store the last run times of periodic tasks. Can be a relative or absolute path, but be aware that the suffix `.db` may be appended to the file name (depending on Python version). Can also be set via the :option:`--schedule` argument to :mod:`~celery.bin.celerybeat`. .. setting:: CELERYBEAT_MAX_LOOP_INTERVAL CELERYBEAT_MAX_LOOP_INTERVAL ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The maximum number of seconds :mod:`~celery.bin.celerybeat` can sleep between checking the schedule. Default is 300 seconds (5 minutes). .. _conf-celerymon: Monitor Server: celerymon ------------------------- .. setting:: CELERYMON_LOG_FORMAT CELERYMON_LOG_FORMAT ~~~~~~~~~~~~~~~~~~~~ The format to use for log messages. Default is `[%(asctime)s: %(levelname)s/%(processName)s] %(message)s` See the Python :mod:`logging` module for more information about log formats. .. _conf-deprecated: Deprecated Settings ------------------- These settings have been deprecated and should no longer used, as they will be removed in future versions. .. setting:: CELERY_AMQP_TASK_RESULT_EXPIRES CELERY_AMQP_TASK_RESULT_EXPIRES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. deprecated:: 2.5 The time in seconds of which the task result queues should expire. This setting is deprecated, and will be removed in version 3.0. Please use :setting:`CELERY_TASK_RESULT_EXPIRES` instead. .. note:: AMQP result expiration requires RabbitMQ versions 2.1.0 and higher. .. setting:: CELERY_TASK_ERROR_WHITELIST CELERY_TASK_ERROR_WHITELIST ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. deprecated:: 2.5 A white list of exceptions to send error emails for. This option is pending deprecation and is scheduled for removal in version 3.0. .. setting:: CELERYD_LOG_FILE CELERYD_LOG_FILE ~~~~~~~~~~~~~~~~ .. deprecated:: 2.4 This option is deprecated and is scheduled for removal in version 3.0. Please use the :option:`--logfile` argument instead. The default file name the worker daemon logs messages to. Can be overridden using the :option:`--logfile` option to :mod:`~celery.bin.celeryd`. The default is :const:`None` (`stderr`) .. setting:: CELERYD_LOG_LEVEL CELERYD_LOG_LEVEL ~~~~~~~~~~~~~~~~~ .. deprecated:: 2.4 This option is deprecated and is scheduled for removal in version 3.0. Please use the :option:`--loglevel` argument instead. Worker log level, can be one of :const:`DEBUG`, :const:`INFO`, :const:`WARNING`, :const:`ERROR` or :const:`CRITICAL`. Can also be set via the :option:`--loglevel` argument to :mod:`~celery.bin.celeryd`. See the :mod:`logging` module for more information. .. setting:: CELERYBEAT_LOG_FILE CELERYBEAT_LOG_FILE ~~~~~~~~~~~~~~~~~~~ .. deprecated:: 2.4 This option is deprecated and is scheduled for removal in version 3.0. Please use the :option:`--logfile` argument instead. The default file name to log messages to. Can be overridden using the `--logfile` option to :mod:`~celery.bin.celerybeat`. The default is :const:`None` (`stderr`). .. setting:: CELERYBEAT_LOG_LEVEL CELERYBEAT_LOG_LEVEL ~~~~~~~~~~~~~~~~~~~~ .. deprecated:: 2.4 This option is deprecated and is scheduled for removal in version 3.0. Please use the :option:`--loglevel` argument instead. Logging level. Can be any of :const:`DEBUG`, :const:`INFO`, :const:`WARNING`, :const:`ERROR`, or :const:`CRITICAL`. Can also be set via the :option:`--loglevel` argument to :mod:`~celery.bin.celerybeat`. See the :mod:`logging` module for more information. .. setting:: CELERYMON_LOG_FILE CELERYMON_LOG_FILE ~~~~~~~~~~~~~~~~~~ .. deprecated:: 2.4 This option is deprecated and is scheduled for removal in version 3.0. Please use the :option:`--logfile` argument instead. The default file name to log messages to. Can be overridden using the :option:`--logfile` argument to `celerymon`. The default is :const:`None` (`stderr`) .. setting:: CELERYMON_LOG_LEVEL CELERYMON_LOG_LEVEL ~~~~~~~~~~~~~~~~~~~ .. deprecated:: 2.4 This option is deprecated and is scheduled for removal in version 3.0. Please use the :option:`--loglevel` argument instead. Logging level. Can be any of :const:`DEBUG`, :const:`INFO`, :const:`WARNING`, :const:`ERROR`, or :const:`CRITICAL`. See the :mod:`logging` module for more information.