This document describes the current stable version of Celery (5.6). For development docs, go here.

# `celery.backends.database`

SQLAlchemy result store backend.

class celery.backends.database.DatabaseBackend(dburi=None, engine_options=None, url=None, **kwargs)

  The database result backend.

  ResultSession(session_manager=None)
  cleanup()

    Delete expired meta-data.

  exception_safe_to_retry(exc)

    Check if an exception is safe to retry.

    Backends have to overload this method with correct predicates dealing with their exceptions.

    By default no exception is safe to retry, it’s up to backend implementation to define which exceptions are safe.

  property extended_result
  on_backend_retryable_error(exc)

    Hook called before retrying a recoverable backend exception.

  subpolling_interval = 0.5

    Time to sleep between polling each individual item in ResultSet.iterate. as opposed to the interval argument which is for each pass.

  task_cls

    alias of `Task`

  taskset_cls

    alias of `TaskSet`