This document describes the current stable version of Celery (5.3). For development docs, go here.

Source code for

"""Worker Event Dispatcher Bootstep.

``Events`` -> :class:``.
from kombu.common import ignore_errors

from celery import bootsteps

from .connection import Connection

__all__ = ('Events',)

[docs]class Events(bootsteps.StartStopStep): """Service used for sending monitoring events.""" requires = (Connection,) def __init__(self, c, task_events=True, without_heartbeat=False, without_gossip=False, **kwargs): self.groups = None if task_events else ['worker'] self.send_events = ( task_events or not without_gossip or not without_heartbeat ) self.enabled = self.send_events c.event_dispatcher = None super().__init__(c, **kwargs)
[docs] def start(self, c): # flush events sent while connection was down. prev = self._close(c) dis = c.event_dispatcher = c.connection_for_write(), hostname=c.hostname, enabled=self.send_events, groups=self.groups, # we currently only buffer events when the event loop is enabled # XXX This excludes eventlet/gevent, which should actually buffer. buffer_group=['task'] if c.hub else None, on_send_buffered=c.on_send_event_buffered if c.hub else None, ) if prev: dis.extend_buffer(prev) dis.flush()
[docs] def stop(self, c): pass
def _close(self, c): if c.event_dispatcher: dispatcher = c.event_dispatcher # remember changes from remote control commands: self.groups = dispatcher.groups # close custom connection if dispatcher.connection: ignore_errors(c, dispatcher.connection.close) ignore_errors(c, dispatcher.close) c.event_dispatcher = None return dispatcher
[docs] def shutdown(self, c): self._close(c)