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

Source code for celery.exceptions

"""Celery error types.

Error Hierarchy
===============

- :exc:`Exception`
    - :exc:`celery.exceptions.CeleryError`
        - :exc:`~celery.exceptions.ImproperlyConfigured`
        - :exc:`~celery.exceptions.SecurityError`
        - :exc:`~celery.exceptions.TaskPredicate`
            - :exc:`~celery.exceptions.Ignore`
            - :exc:`~celery.exceptions.Reject`
            - :exc:`~celery.exceptions.Retry`
        - :exc:`~celery.exceptions.TaskError`
            - :exc:`~celery.exceptions.QueueNotFound`
            - :exc:`~celery.exceptions.IncompleteStream`
            - :exc:`~celery.exceptions.NotRegistered`
            - :exc:`~celery.exceptions.AlreadyRegistered`
            - :exc:`~celery.exceptions.TimeoutError`
            - :exc:`~celery.exceptions.MaxRetriesExceededError`
            - :exc:`~celery.exceptions.TaskRevokedError`
            - :exc:`~celery.exceptions.InvalidTaskError`
            - :exc:`~celery.exceptions.ChordError`
        - :exc:`~celery.exceptions.BackendError`
            - :exc:`~celery.exceptions.BackendGetMetaError`
            - :exc:`~celery.exceptions.BackendStoreError`
    - :class:`kombu.exceptions.KombuError`
        - :exc:`~celery.exceptions.OperationalError`

            Raised when a transport connection error occurs while
            sending a message (be it a task, remote control command error).

            .. note::
                This exception does not inherit from
                :exc:`~celery.exceptions.CeleryError`.
    - **billiard errors** (prefork pool)
        - :exc:`~celery.exceptions.SoftTimeLimitExceeded`
        - :exc:`~celery.exceptions.TimeLimitExceeded`
        - :exc:`~celery.exceptions.WorkerLostError`
        - :exc:`~celery.exceptions.Terminated`
- :class:`UserWarning`
    - :class:`~celery.exceptions.CeleryWarning`
        - :class:`~celery.exceptions.AlwaysEagerIgnored`
        - :class:`~celery.exceptions.DuplicateNodenameWarning`
        - :class:`~celery.exceptions.FixupWarning`
        - :class:`~celery.exceptions.NotConfigured`
        - :class:`~celery.exceptions.SecurityWarning`
- :exc:`BaseException`
    - :exc:`SystemExit`
        - :exc:`~celery.exceptions.WorkerTerminate`
        - :exc:`~celery.exceptions.WorkerShutdown`
"""

import numbers

from billiard.exceptions import SoftTimeLimitExceeded, Terminated, TimeLimitExceeded, WorkerLostError
from click import ClickException
from kombu.exceptions import OperationalError

__all__ = (
    'reraise',
    # Warnings
    'CeleryWarning',
    'AlwaysEagerIgnored', 'DuplicateNodenameWarning',
    'FixupWarning', 'NotConfigured', 'SecurityWarning',

    # Core errors
    'CeleryError',
    'ImproperlyConfigured', 'SecurityError',

    # Kombu (messaging) errors.
    'OperationalError',

    # Task semi-predicates
    'TaskPredicate', 'Ignore', 'Reject', 'Retry',

    # Task related errors.
    'TaskError', 'QueueNotFound', 'IncompleteStream',
    'NotRegistered', 'AlreadyRegistered', 'TimeoutError',
    'MaxRetriesExceededError', 'TaskRevokedError',
    'InvalidTaskError', 'ChordError',

    # Backend related errors.
    'BackendError', 'BackendGetMetaError', 'BackendStoreError',

    # Billiard task errors.
    'SoftTimeLimitExceeded', 'TimeLimitExceeded',
    'WorkerLostError', 'Terminated',

    # Deprecation warnings (forcing Python to emit them).
    'CPendingDeprecationWarning', 'CDeprecationWarning',

    # Worker shutdown semi-predicates (inherits from SystemExit).
    'WorkerShutdown', 'WorkerTerminate',

    'CeleryCommandException',
)

UNREGISTERED_FMT = """\
Task of kind {0} never registered, please make sure it's imported.\
"""


[docs]def reraise(tp, value, tb=None): """Reraise exception.""" if value.__traceback__ is not tb: raise value.with_traceback(tb) raise value
[docs]class CeleryWarning(UserWarning): """Base class for all Celery warnings."""
[docs]class AlwaysEagerIgnored(CeleryWarning): """send_task ignores :setting:`task_always_eager` option."""
[docs]class DuplicateNodenameWarning(CeleryWarning): """Multiple workers are using the same nodename."""
[docs]class FixupWarning(CeleryWarning): """Fixup related warning."""
[docs]class NotConfigured(CeleryWarning): """Celery hasn't been configured, as no config module has been found."""
[docs]class SecurityWarning(CeleryWarning): """Potential security issue found."""
[docs]class CeleryError(Exception): """Base class for all Celery errors."""
[docs]class TaskPredicate(CeleryError): """Base class for task-related semi-predicates."""
[docs]class Retry(TaskPredicate): """The task is to be retried later.""" #: Optional message describing context of retry. message = None #: Exception (if any) that caused the retry to happen. exc = None #: Time of retry (ETA), either :class:`numbers.Real` or #: :class:`~datetime.datetime`. when = None def __init__(self, message=None, exc=None, when=None, is_eager=False, sig=None, **kwargs): from kombu.utils.encoding import safe_repr self.message = message if isinstance(exc, str): self.exc, self.excs = None, exc else: self.exc, self.excs = exc, safe_repr(exc) if exc else None self.when = when self.is_eager = is_eager self.sig = sig super().__init__(self, exc, when, **kwargs)
[docs] def humanize(self): if isinstance(self.when, numbers.Number): return f'in {self.when}s' return f'at {self.when}'
def __str__(self): if self.message: return self.message if self.excs: return f'Retry {self.humanize()}: {self.excs}' return f'Retry {self.humanize()}' def __reduce__(self): return self.__class__, (self.message, self.exc, self.when)
RetryTaskError = Retry # XXX compat
[docs]class Ignore(TaskPredicate): """A task can raise this to ignore doing state updates."""
[docs]class Reject(TaskPredicate): """A task can raise this if it wants to reject/re-queue the message.""" def __init__(self, reason=None, requeue=False): self.reason = reason self.requeue = requeue super().__init__(reason, requeue) def __repr__(self): return f'reject requeue={self.requeue}: {self.reason}'
[docs]class ImproperlyConfigured(CeleryError): """Celery is somehow improperly configured."""
[docs]class SecurityError(CeleryError): """Security related exception."""
[docs]class TaskError(CeleryError): """Task related errors."""
[docs]class QueueNotFound(KeyError, TaskError): """Task routed to a queue not in ``conf.queues``."""
[docs]class IncompleteStream(TaskError): """Found the end of a stream of data, but the data isn't complete."""
[docs]class NotRegistered(KeyError, TaskError): """The task is not registered.""" def __repr__(self): return UNREGISTERED_FMT.format(self)
[docs]class AlreadyRegistered(TaskError): """The task is already registered."""
# XXX Unused
[docs]class TimeoutError(TaskError): """The operation timed out."""
[docs]class MaxRetriesExceededError(TaskError): """The tasks max restart limit has been exceeded.""" def __init__(self, *args, **kwargs): self.task_args = kwargs.pop("task_args", []) self.task_kwargs = kwargs.pop("task_kwargs", dict()) super().__init__(*args, **kwargs)
[docs]class TaskRevokedError(TaskError): """The task has been revoked, so no result available."""
[docs]class InvalidTaskError(TaskError): """The task has invalid data or ain't properly constructed."""
[docs]class ChordError(TaskError): """A task part of the chord raised an exception."""
[docs]class CPendingDeprecationWarning(PendingDeprecationWarning): """Warning of pending deprecation."""
[docs]class CDeprecationWarning(DeprecationWarning): """Warning of deprecation."""
[docs]class WorkerTerminate(SystemExit): """Signals that the worker should terminate immediately."""
SystemTerminate = WorkerTerminate # XXX compat
[docs]class WorkerShutdown(SystemExit): """Signals that the worker should perform a warm shutdown."""
[docs]class BackendError(Exception): """An issue writing or reading to/from the backend."""
[docs]class BackendGetMetaError(BackendError): """An issue reading from the backend.""" def __init__(self, *args, **kwargs): self.task_id = kwargs.get('task_id', "") def __repr__(self): return super().__repr__() + " task_id:" + self.task_id
[docs]class BackendStoreError(BackendError): """An issue writing to the backend.""" def __init__(self, *args, **kwargs): self.state = kwargs.get('state', "") self.task_id = kwargs.get('task_id', "") def __repr__(self): return super().__repr__() + " state:" + self.state + " task_id:" + self.task_id
[docs]class CeleryCommandException(ClickException): """A general command exception which stores an exit code.""" def __init__(self, message, exit_code): super().__init__(message=message) self.exit_code = exit_code