This document describes the current stable version of Celery (5.5). For development docs, go here.

celery.worker.consumer.consumer

Worker Consumer Blueprint.

This module contains the components responsible for consuming messages from the broker, processing the messages and keeping the broker connections up and running.

class celery.worker.consumer.consumer.Consumer(on_task_request, init_callback=<function noop>, hostname=None, pool=None, app=None, timer=None, controller=None, hub=None, amqheartbeat=None, worker_options=None, disable_rate_limits=False, initial_prefetch_count=2, prefetch_multiplier=1, **kwargs)

Consumer blueprint.

class Blueprint(steps=None, name=None, on_start=None, on_close=None, on_stopped=None)

Consumer blueprint.

default_steps = ['celery.worker.consumer.connection:Connection', 'celery.worker.consumer.mingle:Mingle', 'celery.worker.consumer.events:Events', 'celery.worker.consumer.gossip:Gossip', 'celery.worker.consumer.heart:Heart', 'celery.worker.consumer.control:Control', 'celery.worker.consumer.tasks:Tasks', 'celery.worker.consumer.delayed_delivery:DelayedDelivery', 'celery.worker.consumer.consumer:Evloop', 'celery.worker.consumer.agent:Agent']

name = 'Consumer'

shutdown(parent)

Strategies

alias of dict

add_task_queue(queue, exchange=None, exchange_type=None, routing_key=None, **options)

apply_eta_task(task)

Method called by the timer to apply a task with an ETA/countdown.

bucket_for_task(type)

call_soon(p, *args, **kwargs)

cancel_all_unacked_requests()

Cancel all active requests that either do not require late acknowledgments or, if they do, have not been acknowledged yet.

cancel_task_queue(queue)

connect()

Establish the broker connection used for consuming tasks.

Retries establishing the connection if the broker_connection_retry setting is enabled

connection_for_read(heartbeat=None)

connection_for_write(url=None, heartbeat=None)

create_task_handler(promise=<class 'vine.promises.promise'>)

ensure_connected(conn)

first_connection_attempt = True

This flag will be turned off after the first failed connection attempt.

init_callback = None

Optional callback called the first time the worker is ready to receive tasks.

loop_args()

property max_prefetch_count

on_close()

on_connection_error_after_connected(exc)

on_connection_error_before_connected(exc)

on_decode_error(message, exc)

Callback called if an error occurs while decoding a message.

Simply logs the error and acknowledges the message so it doesn’t enter a loop.

Parameters:

• message (kombu.Message) – The message received.

• exc (Exception) – The exception being handled.

on_invalid_task(body, message, exc)

on_ready()

on_send_event_buffered()

on_unknown_message(body, message)

on_unknown_task(body, message, exc)

perform_pending_operations()

pool = None

The current worker pool instance.

register_with_event_loop(hub)

reset_rate_limits()

restart_count = -1

shutdown()

start()

stop()

timer = None

A timer used for high-priority internal tasks, such as sending heartbeats.

update_strategies()

class celery.worker.consumer.consumer.Evloop(parent, **kwargs)

Event loop service.

Note

This is always started last.

label = 'event loop'

last = True

name = 'celery.worker.consumer.consumer.Evloop'

patch_all(c)

start(c)

celery.worker.consumer.consumer.dump_body(m, body)

Format message body for debugging purposes.