This document describes the current stable version of Celery (3.1). For development docs, go here.
Source code for celery.worker.state
# -*- coding: utf-8 -*-
"""
celery.worker.state
~~~~~~~~~~~~~~~~~~~
Internal worker state (global)
This includes the currently active and reserved tasks,
statistics, and revoked tasks.
"""
from __future__ import absolute_import
import os
import sys
import platform
import shelve
import zlib
from kombu.serialization import pickle, pickle_protocol
from kombu.utils import cached_property
from celery import __version__
from celery.datastructures import LimitedSet
from celery.exceptions import WorkerShutdown, WorkerTerminate
from celery.five import Counter
__all__ = ['SOFTWARE_INFO', 'reserved_requests', 'active_requests',
'total_count', 'revoked', 'task_reserved', 'maybe_shutdown',
'task_accepted', 'task_ready', 'task_reserved', 'task_ready',
'Persistent']
#: Worker software/platform information.
SOFTWARE_INFO = {'sw_ident': 'py-celery',
'sw_ver': __version__,
'sw_sys': platform.system()}
#: maximum number of revokes to keep in memory.
REVOKES_MAX = 50000
#: how many seconds a revoke will be active before
#: being expired when the max limit has been exceeded.
REVOKE_EXPIRES = 10800
#: set of all reserved :class:`~celery.worker.job.Request`'s.
reserved_requests = set()
#: set of currently active :class:`~celery.worker.job.Request`'s.
active_requests = set()
#: count of tasks accepted by the worker, sorted by type.
total_count = Counter()
#: count of all tasks accepted by the worker
all_total_count = [0]
#: the list of currently revoked tasks. Persistent if statedb set.
revoked = LimitedSet(maxlen=REVOKES_MAX, expires=REVOKE_EXPIRES)
#: Update global state when a task has been reserved.
task_reserved = reserved_requests.add
should_stop = False
should_terminate = False
def reset_state():
reserved_requests.clear()
active_requests.clear()
total_count.clear()
all_total_count[:] = [0]
revoked.clear()
[docs]def maybe_shutdown():
if should_stop:
raise WorkerShutdown()
elif should_terminate:
raise WorkerTerminate()
[docs]def task_accepted(request, _all_total_count=all_total_count):
"""Updates global state when a task has been accepted."""
active_requests.add(request)
total_count[request.name] += 1
all_total_count[0] += 1
def task_ready(request):
"""Updates global state when a task is ready."""
active_requests.discard(request)
reserved_requests.discard(request)
C_BENCH = os.environ.get('C_BENCH') or os.environ.get('CELERY_BENCH')
C_BENCH_EVERY = int(os.environ.get('C_BENCH_EVERY') or
os.environ.get('CELERY_BENCH_EVERY') or 1000)
if C_BENCH: # pragma: no cover
import atexit
from billiard import current_process
from celery.five import monotonic
from celery.utils.debug import memdump, sample_mem
all_count = 0
bench_first = None
bench_start = None
bench_last = None
bench_every = C_BENCH_EVERY
bench_sample = []
__reserved = task_reserved
__ready = task_ready
if current_process()._name == 'MainProcess':
@atexit.register
def on_shutdown():
if bench_first is not None and bench_last is not None:
print('- Time spent in benchmark: {0!r}'.format(
bench_last - bench_first))
print('- Avg: {0}'.format(
sum(bench_sample) / len(bench_sample)))
memdump()
def task_reserved(request): # noqa
global bench_start
global bench_first
now = None
if bench_start is None:
bench_start = now = monotonic()
if bench_first is None:
bench_first = now
return __reserved(request)
[docs] def task_ready(request): # noqa
global all_count
global bench_start
global bench_last
all_count += 1
if not all_count % bench_every:
now = monotonic()
diff = now - bench_start
print('- Time spent processing {0} tasks (since first '
'task received): ~{1:.4f}s\n'.format(bench_every, diff))
sys.stdout.flush()
bench_start = bench_last = now
bench_sample.append(diff)
sample_mem()
return __ready(request)
[docs]class Persistent(object):
"""This is the persistent data stored by the worker when
:option:`--statedb` is enabled.
It currently only stores revoked task id's.
"""
storage = shelve
protocol = pickle_protocol
compress = zlib.compress
decompress = zlib.decompress
_is_open = False
def __init__(self, state, filename, clock=None):
self.state = state
self.filename = filename
self.clock = clock
self.merge()
[docs] def open(self):
return self.storage.open(
self.filename, protocol=self.protocol, writeback=True,
)
def _merge_with(self, d):
self._merge_revoked(d)
self._merge_clock(d)
return d
def _sync_with(self, d):
self._revoked_tasks.purge()
d.update(
__proto__=3,
zrevoked=self.compress(self._dumps(self._revoked_tasks)),
clock=self.clock.forward() if self.clock else 0,
)
return d
def _merge_clock(self, d):
if self.clock:
d['clock'] = self.clock.adjust(d.get('clock') or 0)
def _merge_revoked(self, d):
try:
self._merge_revoked_v3(d['zrevoked'])
except KeyError:
try:
self._merge_revoked_v2(d.pop('revoked'))
except KeyError:
pass
# purge expired items at boot
self._revoked_tasks.purge()
def _merge_revoked_v3(self, zrevoked):
if zrevoked:
self._revoked_tasks.update(pickle.loads(self.decompress(zrevoked)))
def _merge_revoked_v2(self, saved):
if not isinstance(saved, LimitedSet):
# (pre 3.0.18) used to be stored as a dict
return self._merge_revoked_v1(saved)
self._revoked_tasks.update(saved)
def _merge_revoked_v1(self, saved):
add = self._revoked_tasks.add
for item in saved:
add(item)
def _dumps(self, obj):
return pickle.dumps(obj, protocol=self.protocol)
@property
def _revoked_tasks(self):
return self.state.revoked
@cached_property
