# Change history {#changelog-3.1}

This document contains change notes for bugfix releases in the 3.1.x
series (Cipater), please see `whatsnew-3.1`{.interpreted-text
role="ref"} for an overview of what\'s new in Celery 3.1.

## 3.1.26 {#version-3.1.26}

release-date

:   2018-23-03 16:00 PM IST

release-by

:   Omer Katz

-   Fixed a crash caused by tasks cycling between Celery 3 and Celery 4
    workers.

## 3.1.25 {#version-3.1.25}

release-date

:   2016-10-10 12:00 PM PDT

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.37 <kombu:version-3.0.37>`{.interpreted-text
    >     role="ref"}

-   Fixed problem with chords in group introduced in 3.1.24 (Issue
    #3504).

## 3.1.24 {#version-3.1.24}

release-date

:   2016-09-30 04:21 PM PDT

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.36 <kombu:version-3.0.36>`{.interpreted-text
    >     role="ref"}.

-   Now supports Task protocol 2 from the future 4.0 release.

    > Workers running 3.1.24 are now able to process messages sent using
    > the [new task message
    > protocol](https://docs.celeryq.dev/en/master/internals/protocol.html#version-2)
    > to be introduced in Celery 4.0.
    >
    > Users upgrading to Celery 4.0 when this is released are encouraged
    > to upgrade to this version as an intermediate step, as this means
    > workers not yet upgraded will be able to process messages from
    > clients/workers running 4.0.

-   `Task.send_events` can now be set to disable sending of events for
    that task only.

    > Example when defining the task:
    >
    > ``` python
    > @app.task(send_events=False)
    > def add(x, y):
    >     return x + y
    > ```

-   **Utils**: Fixed compatibility with recent
    `psutil`{.interpreted-text role="pypi"} versions (Issue #3262).

-   **Canvas**: Chord now forwards partial arguments to its subtasks.

    > Fix contributed by Tayfun Sen.

-   **App**: Arguments to app such as `backend`, `broker`, etc are now
    pickled and sent to the child processes on Windows.

    > Fix contributed by Jeremy Zafran.

-   **Deployment**: Generic init scripts now supports being symlinked in
    runlevel directories (Issue #3208).

-   **Deployment**: Updated CentOS scripts to work with CentOS 7.

    > Contributed by Joe Sanford.

-   **Events**: The curses monitor no longer crashes when the result of
    a task is empty.

    > Fix contributed by Dongweiming.

-   **Worker**: `repr(worker)` would crash when called early in the
    startup process (Issue #2514).

-   **Tasks**: GroupResult now defines \_\_bool\_\_ and \_\_nonzero\_\_.

    > This is to fix an issue where a ResultSet or GroupResult with an
    > empty result list are not properly tupled with the as_tuple()
    > method when it is a parent result. This is due to the as_tuple()
    > method performing a logical and operation on the ResultSet.
    >
    > Fix contributed by Colin McIntosh.

-   **Worker**: Fixed wrong values in autoscale related logging message.

    > Fix contributed by `@raducc`.

-   Documentation improvements by

    > -   Alexandru Chirila
    > -   Michael Aquilina
    > -   Mikko Ekström
    > -   Mitchel Humpherys
    > -   Thomas A. Neil
    > -   Tiago Moreira Vieira
    > -   Yuriy Syrovetskiy
    > -   `@dessant`

## 3.1.23 {#version-3.1.23}

release-date

:   2016-03-09 06:00 P.M PST

release-by

:   Ask Solem

-   **Programs**: Last release broke support for the `--hostnmame`
    argument to `celery multi`{.interpreted-text role="program"} and
    `celery worker --detach`{.interpreted-text role="program"} (Issue
    #3103).
-   **Results**: MongoDB result backend could crash the worker at
    startup if not configured using an URL.

## 3.1.22 {#version-3.1.22}

release-date

:   2016-03-07 01:30 P.M PST

release-by

:   Ask Solem

-   **Programs**: The worker would crash immediately on startup on
    `backend.as_uri()` when using some result backends (Issue #3094).
-   **Programs**: `celery multi`{.interpreted-text
    role="program"}/`celery worker --detach`{.interpreted-text
    role="program"} would create an extraneous logfile including literal
    formats (e.g. `%I`) in the filename (Issue #3096).

## 3.1.21 {#version-3.1.21}

release-date

:   2016-03-04 11:16 a.m. PST

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.34 <kombu:version-3.0.34>`{.interpreted-text
    >     role="ref"}.
    > -   Now depends on `billiard`{.interpreted-text role="mod"}
    >     3.3.0.23.

-   **Prefork pool**: Fixes 100% CPU loop on Linux
    `epoll`{.interpreted-text role="manpage"} (Issue #1845).

    > Also potential fix for: Issue #2142, Issue #2606

-   **Prefork pool**: Fixes memory leak related to processes exiting
    (Issue #2927).

-   **Worker**: Fixes crash at start-up when trying to censor passwords
    in MongoDB and Cache result backend URLs (Issue #3079, Issue #3045,
    Issue #3049, Issue #3068, Issue #3073).

    > Fix contributed by Maxime Verger.

-   **Task**: An exception is now raised if countdown/expires is less
    than -2147483648 (Issue #3078).

-   **Programs**: `celery shell --ipython`{.interpreted-text
    role="program"} now compatible with newer
    `IPython`{.interpreted-text role="pypi"} versions.

-   **Programs**: The DuplicateNodeName warning emitted by
    inspect/control now includes a list of the node names returned.

    > Contributed by Sebastian Kalinowski.

-   **Utils**: The `.discard(item)` method of
    `~celery.utils.collections.LimitedSet`{.interpreted-text
    role="class"} didn\'t actually remove the item (Issue #3087).

    > Fix contributed by Dave Smith.

-   **Worker**: Node name formatting now emits less confusing error
    message for unmatched format keys (Issue #3016).

-   **Results**: RPC/AMQP backends: Fixed deserialization of JSON
    exceptions (Issue #2518).

    > Fix contributed by Allard Hoeve.

-   **Prefork pool**: The [process inqueue damaged]{.title-ref} error
    message now includes the original exception raised.

-   **Documentation**: Includes improvements by:

    > -   Jeff Widman.

## 3.1.20 {#version-3.1.20}

release-date

:   2016-01-22 06:50 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.33 <kombu:version-3.0.33>`{.interpreted-text
    >     role="ref"}.
    >
    > -   Now depends on `billiard`{.interpreted-text role="mod"}
    >     3.3.0.22.
    >
    >     > Includes binary wheels for Microsoft Windows x86 and x86_64!

-   **Task**: Error emails now uses `utf-8` character set by default
    (Issue #2737).

-   **Task**: Retry now forwards original message headers (Issue #3017).

-   **Worker**: Bootsteps can now hook into
    `on_node_join`/`leave`/`lost`.

    > See `extending-consumer-attributes`{.interpreted-text role="ref"}
    > for an example.

-   **Events**: Fixed handling of DST timezones (Issue #2983).

-   **Results**: Redis backend stopped respecting certain settings.

    > Contributed by Jeremy Llewellyn.

-   **Results**: Database backend now properly supports JSON exceptions
    (Issue #2441).

-   **Results**: Redis `new_join` didn\'t properly call task errbacks on
    chord error (Issue #2796).

-   **Results**: Restores Redis compatibility with Python
    `redis`{.interpreted-text role="pypi"} \< 2.10.0 (Issue #2903).

-   **Results**: Fixed rare issue with chord error handling (Issue
    #2409).

-   **Tasks**: Using queue-name values in
    `CELERY_ROUTES`{.interpreted-text role="setting"} now works again
    (Issue #2987).

-   **General**: Result backend password now sanitized in report output
    (Issue #2812, Issue #2004).

-   **Configuration**: Now gives helpful error message when the result
    backend configuration points to a module, and not a class (Issue
    #2945).

-   **Results**: Exceptions sent by JSON serialized workers are now
    properly handled by pickle configured workers.

-   **Programs**: `celery control autoscale` now works (Issue #2950).

-   **Programs**: `celery beat --detached` now runs after fork
    callbacks.

-   **General**: Fix for LRU cache implementation on Python 3.5 (Issue
    #2897).

    > Contributed by Dennis Brakhane.
    >
    > Python 3.5\'s `OrderedDict` doesn\'t allow mutation while it is
    > being iterated over. This breaks \"update\" if it is called with a
    > dict larger than the maximum size.
    >
    > This commit changes the code to a version that doesn\'t iterate
    > over the dict, and should also be a little bit faster.

-   **Init-scripts**: The beat init-script now properly reports service
    as down when no pid file can be found.

    > Eric Zarowny

-   **Beat**: Added cleaning of corrupted scheduler files for some
    storage backend errors (Issue #2985).

    > Fix contributed by Aleksandr Kuznetsov.

-   **Beat**: Now syncs the schedule even if the schedule is empty.

    > Fix contributed by Colin McIntosh.

-   

    **Supervisord**: Set higher process priority in the `supervisord`{.interpreted-text role="pypi"}

    :   example.

        Contributed by George Tantiras.

-   **Documentation**: Includes improvements by:

    > `Bryson`{.interpreted-text role="github_user"} Caleb Mingle
    > Christopher Martin Dieter Adriaenssens Jason Veatch Jeremy Cline
    > Juan Rossi Kevin Harvey Kevin McCarthy Kirill Pavlov Marco Buttu
    > `Mayflower`{.interpreted-text role="github_user"} Mher Movsisyan
    > Michael Floering `michael-k`{.interpreted-text role="github_user"}
    > Nathaniel Varona Rudy Attias Ryan Luckie Steven Parker
    > `squfrans`{.interpreted-text role="github_user"} Tadej Janež
    > TakesxiSximada Tom S

## 3.1.19 {#version-3.1.19}

release-date

:   2015-10-26 01:00 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.29 <kombu:version-3.0.29>`{.interpreted-text
    >     role="ref"}.
    > -   Now depends on `billiard`{.interpreted-text role="mod"}
    >     3.3.0.21.

-   **Results**: Fixed MongoDB result backend URL parsing problem (Issue
    celery/kombu#375).

-   **Worker**: Task request now properly sets `priority` in
    delivery_info.

    > Fix contributed by Gerald Manipon.

-   **Beat**: PyPy shelve may raise `KeyError` when setting keys (Issue
    #2862).

-   **Programs**: `celery beat --deatched`{.interpreted-text
    role="program"} now working on PyPy.

    > Fix contributed by Krzysztof Bujniewicz.

-   **Results**: Redis result backend now ensures all pipelines are
    cleaned up.

    > Contributed by Justin Patrin.

-   **Results**: Redis result backend now allows for timeout to be set
    in the query portion of the result backend URL.

    > For example `CELERY_RESULT_BACKEND = 'redis://?timeout=10'`
    >
    > Contributed by Justin Patrin.

-   **Results**: `result.get` now properly handles failures where the
    exception value is set to `None`{.interpreted-text role="const"}
    (Issue #2560).

-   **Prefork pool**: Fixed attribute error `proc.dead`.

-   **Worker**: Fixed worker hanging when gossip/heartbeat disabled
    (Issue #1847).

    > Fix contributed by Aaron Webber and Bryan Helmig.

-   **Results**: MongoDB result backend now supports pymongo 3.x (Issue
    #2744).

    > Fix contributed by Sukrit Khera.

-   **Results**: RPC/AMQP backends didn\'t deserialize exceptions
    properly (Issue #2691).

    > Fix contributed by Sukrit Khera.

-   **Programs**: Fixed problem with `celery amqp`{.interpreted-text
    role="program"}\'s `basic_publish` (Issue #2013).

-   **Worker**: Embedded beat now properly sets app for thread/process
    (Issue #2594).

-   **Documentation**: Many improvements and typos fixed.

    > Contributions by:
    >
    > > Carlos Garcia-Dubus
    > > D. Yu `jerry`{.interpreted-text role="github_user"} Jocelyn
    > > Delalande Josh Kupershmidt Juan Rossi
    > > `kanemra`{.interpreted-text role="github_user"} Paul Pearce
    > > Pavel Savchenko Sean Wang Seungha Kim Zhaorong Ma

## 3.1.18 {#version-3.1.18}

release-date

:   2015-04-22 05:30 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.25 <kombu:version-3.0.25>`{.interpreted-text
    >     role="ref"}.
    > -   Now depends on `billiard`{.interpreted-text role="mod"}
    >     3.3.0.20.

-   **Django**: Now supports Django 1.8 (Issue #2536).

    > Fix contributed by Bence Tamas and Mickaël Penhard.

-   **Results**: MongoDB result backend now compatible with pymongo 3.0.

    > Fix contributed by Fatih Sucu.

-   **Tasks**: Fixed bug only happening when a task has multiple
    callbacks (Issue #2515).

    > Fix contributed by NotSqrt.

-   **Commands**: Preload options now support `--arg value` syntax.

    > Fix contributed by John Anderson.

-   **Compat**: A typo caused `celery.log.setup_logging_subsystem` to be
    undefined.

    > Fix contributed by Gunnlaugur Thor Briem.

-   **init-scripts**: The beat generic init-script now uses
    `/bin/sh`{.interpreted-text role="file"} instead of
    `bash`{.interpreted-text role="command"} (Issue #2496).

    > Fix contributed by Jelle Verstraaten.

-   **Django**: Fixed a `TypeError`{.interpreted-text role="exc"}
    sometimes occurring in logging when validating models.

    > Fix contributed by Alexander.

-   **Commands**: Worker now supports new
    `--executable <celery worker --executable>`{.interpreted-text
    role="option"} argument that can be used with
    `celery worker --detach`{.interpreted-text role="option"}.

    > Contributed by Bert Vanderbauwhede.

-   **Canvas**: Fixed crash in chord unlock fallback task (Issue #2404).

-   **Worker**: Fixed rare crash occurring with
    `--autoscale <celery worker --autoscale>`{.interpreted-text
    role="option"} enabled (Issue #2411).

-   **Django**: Properly recycle worker Django database connections when
    the Django `CONN_MAX_AGE` setting is enabled (Issue #2453).

    > Fix contributed by Luke Burden.

## 3.1.17 {#version-3.1.17}

release-date

:   2014-11-19 03:30 p.m. UTC

release-by

:   Ask Solem

::: admonition
Don\'t enable the [CELERYD_FORCE_EXECV]{.title-ref} setting!

Please review your configuration and disable this option if you\'re
using the RabbitMQ or Redis transport.

Keeping this option enabled after 3.1 means the async based prefork pool
will be disabled, which can easily cause instability.
:::

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.24 <kombu:version-3.0.24>`{.interpreted-text
    >     role="ref"}.
    >
    >     > Includes the new Qpid transport coming in Celery 3.2,
    >     > backported to support those who may still require Python 2.6
    >     > compatibility.
    >
    > -   Now depends on `billiard`{.interpreted-text role="mod"}
    >     3.3.0.19.
    >
    > -   `celery[librabbitmq]` now depends on librabbitmq 1.6.1.

-   **Task**: The timing of ETA/countdown tasks were off after the
    example `LocalTimezone` implementation in the Python documentation
    no longer works in Python 3.4. (Issue #2306).

-   **Task**: Raising `~celery.exceptions.Ignore`{.interpreted-text
    role="exc"} no longer sends `task-failed` event (Issue #2365).

-   **Redis result backend**: Fixed unbound local errors.

    > Fix contributed by Thomas French.

-   **Task**: Callbacks wasn\'t called properly if `link` was a list of
    signatures (Issue #2350).

-   **Canvas**: chain and group now handles json serialized signatures
    (Issue #2076).

-   **Results**: `.join_native()` would accidentally treat the `STARTED`
    state as being ready (Issue #2326).

    > This could lead to the chord callback being called with invalid
    > arguments when using chords with the
    > `CELERY_TRACK_STARTED`{.interpreted-text role="setting"} setting
    > enabled.

-   **Canvas**: The `chord_size` attribute is now set for all canvas
    primitives, making sure more combinations will work with the
    `new_join` optimization for Redis (Issue #2339).

-   **Task**: Fixed problem with app not being properly propagated to
    `trace_task` in all cases.

    > Fix contributed by `kristaps`{.interpreted-text
    > role="github_user"}.

-   **Worker**: Expires from task message now associated with a
    timezone.

    > Fix contributed by Albert Wang.

-   **Cassandra result backend**: Fixed problems when using detailed
    mode.

    > When using the Cassandra backend in detailed mode, a regression
    > caused errors when attempting to retrieve results.
    >
    > Fix contributed by Gino Ledesma.

-   **Mongodb Result backend**: Pickling the backend instance will now
    include the original URL (Issue #2347).

    > Fix contributed by Sukrit Khera.

-   **Task**: Exception info wasn\'t properly set for tasks raising
    `~celery.exceptions.Reject`{.interpreted-text role="exc"} (Issue
    #2043).

-   **Worker**: Duplicates are now removed when loading the set of
    revoked tasks from the worker state database (Issue #2336).

-   **celery.contrib.rdb**: Fixed problems with `rdb.set_trace` calling
    stop from the wrong frame.

    > Fix contributed by `llllllllll`{.interpreted-text
    > role="github_user"}.

-   **Canvas**: `chain` and `chord` can now be immutable.

-   **Canvas**: `chord.apply_async` will now keep partial args set in
    `self.args` (Issue #2299).

-   **Results**: Small refactoring so that results are decoded the same
    way in all result backends.

-   **Logging**: The `processName` format was introduced in Python 2.6.2
    so for compatibility this format is now excluded when using earlier
    versions (Issue #1644).

## 3.1.16 {#version-3.1.16}

release-date

:   2014-10-03 06:00 p.m. UTC

release-by

:   Ask Solem

-   **Worker**: 3.1.15 broke
    `-Ofair <celery worker -O>`{.interpreted-text role="option"}
    behavior (Issue #2286).

    > This regression could result in all tasks executing in a single
    > child process if `-Ofair` was enabled.

-   **Canvas**: `celery.signature` now properly forwards app argument in
    all cases.

-   **Task**: `.retry()` didn\'t raise the exception correctly when
    called without a current exception.

    > Fix contributed by Andrea Rabbaglietti.

-   **Worker**: The `enable_events` remote control command disabled
    worker-related events by mistake (Issue #2272).

    > Fix contributed by Konstantinos Koukopoulos.

-   **Django**: Adds support for Django 1.7 class names in
    INSTALLED_APPS when using `app.autodiscover_tasks()` (Issue #2248).

-   **Sphinx**: `celery.contrib.sphinx` now uses `getfullargspec` on
    Python 3 (Issue #2302).

-   **Redis/Cache Backends**: Chords will now run at most once if one or
    more tasks in the chord are executed multiple times for some reason.

## 3.1.15 {#version-3.1.15}

release-date

:   2014-09-14 11:00 p.m. UTC

release-by

:   Ask Solem

-   **Django**: Now makes sure `django.setup()` is called before
    importing any task modules (Django 1.7 compatibility, Issue #2227)
-   **Results**: `result.get()` was misbehaving by calling
    `backend.get_task_meta` in a `finally`{.interpreted-text
    role="keyword"} call leading to AMQP result backend queues not being
    properly cleaned up (Issue #2245).

## 3.1.14 {#version-3.1.14}

release-date

:   2014-09-08 03:00 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.22 <kombu:version-3.0.22>`{.interpreted-text
    >     role="ref"}.

-   **Init-scripts**: The generic worker init-scripts `status` command
    now gets an accurate pidfile list (Issue #1942).

-   

    **Init-scripts**: The generic beat script now implements the `status`

    :   command.

        > Contributed by John Whitlock.

-   **Commands**: Multi now writes informational output to stdout
    instead of stderr.

-   **Worker**: Now ignores not implemented error for `pool.restart`
    (Issue #2153).

-   **Task**: Retry no longer raises retry exception when executed in
    eager mode (Issue #2164).

-   **AMQP Result backend**: Now ensured `on_interval` is called at
    least every second for blocking calls to properly propagate parent
    errors.

-   **Django**: Compatibility with Django 1.7 on Windows (Issue #2126).

-   **Programs**: `!--umask`{.interpreted-text role="option"} argument
    can now be specified in both octal (if starting with 0) or decimal.

## 3.1.13 {#version-3.1.13}

### Security Fixes

-   \[Security:
    [CELERYSA-0002](https://github.com/celery/celery/tree/master/docs/sec/CELERYSA-0002.txt)\]
    Insecure default umask.

    > The built-in utility used to daemonize the Celery worker service
    > sets an insecure umask by default (umask 0).
    >
    > This means that any files or directories created by the worker
    > will end up having world-writable permissions.
    >
    > Special thanks to Red Hat for originally discovering and reporting
    > the issue!
    >
    > This version will no longer set a default umask by default, so if
    > unset the umask of the parent process will be used.

### News

-   **Requirements**

    > -   Now depends on
    >     `Kombu 3.0.21 <kombu:version-3.0.21>`{.interpreted-text
    >     role="ref"}.
    > -   Now depends on `billiard`{.interpreted-text role="mod"}
    >     3.3.0.18.

-   **App**: `backend` argument now also sets the
    `CELERY_RESULT_BACKEND`{.interpreted-text role="setting"} setting.

-   **Task**: `signature_from_request` now propagates `reply_to` so that
    the RPC backend works with retried tasks (Issue #2113).

-   **Task**: `retry` will no longer attempt to re-queue the task if
    sending the retry message fails.

    > Unrelated exceptions being raised could cause a message loop, so
    > it was better to remove this behavior.

-   **Beat**: Accounts for standard 1ms drift by always waking up 0.010s
    earlier.

    > This will adjust the latency so that the periodic tasks won\'t
    > move 1ms after every invocation.

-   Documentation fixes

    > Contributed by Yuval Greenfield, Lucas Wiman,
    > `nicholsonjf`{.interpreted-text role="github_user"}.

-   **Worker**: Removed an outdated assert statement that could lead to
    errors being masked (Issue #2086).

## 3.1.12 {#version-3.1.12}

release-date

:   2014-06-09 10:12 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**

    > Now depends on
    > `Kombu 3.0.19 <kombu:version-3.0.19>`{.interpreted-text
    > role="ref"}.

-   **App**: Connections weren\'t being closed after fork due to an
    error in the after fork handler (Issue #2055).

    > This could manifest itself by causing framing errors when using
    > RabbitMQ. (`Unexpected frame`).

-   **Django**: `django.setup()` was being called too late when using
    Django 1.7 (Issue #1802).

-   **Django**: Fixed problems with event timezones when using Django
    (`Substantial drift`).

    > Celery didn\'t take into account that Django modifies the
    > `time.timeone` attributes and friends.

-   **Canvas**: `Signature.link` now works when the link option is a
    scalar value (Issue #2019).

-   **Prefork pool**: Fixed race conditions for when file descriptors
    are removed from the event loop.

    > Fix contributed by Roger Hu.

-   **Prefork pool**: Improved solution for dividing tasks between child
    processes.

    > This change should improve performance when there are many child
    > processes, and also decrease the chance that two subsequent tasks
    > are written to the same child process.

-   **Worker**: Now ignores unknown event types, instead of crashing.

    > Fix contributed by Illes Solt.

-   **Programs**: `celery worker --detach`{.interpreted-text
    role="program"} no longer closes open file descriptors when
    `C_FAKEFORK`{.interpreted-text role="envvar"} is used so that the
    workers output can be seen.

-   **Programs**: The default working directory for `celery worker
    --detach`{.interpreted-text role="program"} is now the current
    working directory, not `/`.

-   **Canvas**: `signature(s, app=app)` didn\'t upgrade serialized
    signatures to their original class (`subtask_type`) when the `app`
    keyword argument was used.

-   **Control**: The `duplicate nodename` warning emitted by control
    commands now shows the duplicate node name.

-   **Tasks**: Can now call `ResultSet.get()` on a result set without
    members.

    > Fix contributed by Alexey Kotlyarov.

-   **App**: Fixed strange traceback mangling issue for
    `app.connection_or_acquire`.

-   **Programs**: The `celery multi stopwait`{.interpreted-text
    role="program"} command is now documented in usage.

-   **Other**: Fixed cleanup problem with `PromiseProxy` when an error
    is raised while trying to evaluate the promise.

-   **Other**: The utility used to censor configuration values now
    handles non-string keys.

    > Fix contributed by Luke Pomfrey.

-   **Other**: The `inspect conf` command didn\'t handle non-string keys
    well.

    > Fix contributed by Jay Farrimond.

-   **Programs**: Fixed argument handling problem in
    `celery worker --detach`{.interpreted-text role="program"}.

    > Fix contributed by Dmitry Malinovsky.

-   **Programs**: `celery worker --detach`{.interpreted-text
    role="program"} didn\'t forward working directory option (Issue
    #2003).

-   **Programs**: `celery inspect registered`{.interpreted-text
    role="program"} no longer includes the list of built-in tasks.

-   **Worker**: The `requires` attribute for boot steps weren\'t being
    handled correctly (Issue #2002).

-   **Eventlet**: The eventlet pool now supports the `pool_grow` and
    `pool_shrink` remote control commands.

    > Contributed by Mher Movsisyan.

-   **Eventlet**: The eventlet pool now implements statistics for
    `` `celery inspect stats ``{.interpreted-text role="program"}\`.

    > Contributed by Mher Movsisyan.

-   **Documentation**: Clarified `Task.rate_limit` behavior.

    > Contributed by Jonas Haag.

-   **Documentation**: `AbortableTask` examples now updated to use the
    new API (Issue #1993).

-   **Documentation**: The security documentation examples used an out
    of date import.

    > Fix contributed by Ian Dees.

-   **Init-scripts**: The CentOS init-scripts didn\'t quote
    `CELERY_CHDIR`{.interpreted-text role="envvar"}.

    > Fix contributed by `ffeast`{.interpreted-text role="github_user"}.

## 3.1.11 {#version-3.1.11}

release-date

:   2014-04-16 11:00 p.m. UTC

release-by

:   Ask Solem

-   **Now compatible with RabbitMQ 3.3.0**

    > You need to run Celery 3.1.11 or later when using RabbitMQ 3.3,
    > and if you use the `librabbitmq` module you also have to upgrade
    > to librabbitmq 1.5.0:
    >
    > ``` bash
    > $ pip install -U librabbitmq
    > ```

-   **Requirements**:

    > -   Now depends on
    >     `Kombu 3.0.15 <kombu:version-3.0.15>`{.interpreted-text
    >     role="ref"}.
    > -   Now depends on [billiard
    >     3.3.0.17](https://github.com/celery/billiard/blob/master/CHANGES.txt).
    > -   Bundle `celery[librabbitmq]` now depends on
    >     `librabbitmq`{.interpreted-text role="mod"} 1.5.0.

-   **Tasks**: The `CELERY_DEFAULT_DELIVERY_MODE`{.interpreted-text
    role="setting"} setting was being ignored (Issue #1953).

-   **Worker**: New
    `celery worker --heartbeat-interval`{.interpreted-text
    role="option"} can be used to change the time (in seconds) between
    sending event heartbeats.

    > Contributed by Matthew Duggan and Craig Northway.

-   **App**: Fixed memory leaks occurring when creating lots of
    temporary app instances (Issue #1949).

-   **MongoDB**: SSL configuration with non-MongoDB transport breaks
    MongoDB results backend (Issue #1973).

    > Fix contributed by Brian Bouterse.

-   **Logging**: The color formatter accidentally modified `record.msg`
    (Issue #1939).

-   **Results**: Fixed problem with task trails being stored multiple
    times, causing `result.collect()` to hang (Issue #1936, Issue
    #1943).

-   **Results**: `ResultSet` now implements a `.backend` attribute for
    compatibility with `AsyncResult`.

-   **Results**: `.forget()` now also clears the local cache.

-   **Results**: Fixed problem with multiple calls to
    `result._set_cache` (Issue #1940).

-   **Results**: `join_native` populated result cache even if disabled.

-   **Results**: The YAML result serializer should now be able to handle
    storing exceptions.

-   **Worker**: No longer sends task error emails for expected errors
    (in `@task(throws=(..., )))`.

-   **Canvas**: Fixed problem with exception deserialization when using
    the JSON serializer (Issue #1987).

-   **Eventlet**: Fixes crash when `celery.contrib.batches` attempted to
    cancel a non-existing timer (Issue #1984).

-   Can now import `celery.version_info_t`, and `celery.five` (Issue
    #1968).

## 3.1.10 {#version-3.1.10}

release-date

:   2014-03-22 09:40 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**:

    > -   Now depends on
    >     `Kombu 3.0.14 <kombu:version-3.0.14>`{.interpreted-text
    >     role="ref"}.

-   **Results**:

    > Reliability improvements to the SQLAlchemy database backend.
    > Previously the connection from the MainProcess was improperly
    > shared with the workers. (Issue #1786)

-   **Redis:** Important note about events (Issue #1882).

    > There\'s a new transport option for Redis that enables monitors to
    > filter out unwanted events. Enabling this option in the workers
    > will increase performance considerably:
    >
    > ``` python
    > BROKER_TRANSPORT_OPTIONS = {'fanout_patterns': True}
    > ```
    >
    > Enabling this option means that your workers won\'t be able to see
    > workers with the option disabled (or is running an older version
    > of Celery), so if you do enable it then make sure you do so on all
    > nodes.
    >
    > See `redis-caveats`{.interpreted-text role="ref"}.
    >
    > This will be the default in Celery 3.2.

-   **Results**: The `@AsyncResult`{.interpreted-text role="class"}
    object now keeps a local cache of the final state of the task.

    > This means that the global result cache can finally be disabled,
    > and you can do so by setting
    > `CELERY_MAX_CACHED_RESULTS`{.interpreted-text role="setting"} to
    > `-1`{.interpreted-text role="const"}. The lifetime of the cache
    > will then be bound to the lifetime of the result object, which
    > will be the default behavior in Celery 3.2.

-   **Events**: The \"Substantial drift\" warning message is now logged
    once per node name only (Issue #1802).

-   **Worker**: Ability to use one log file per child process when using
    the prefork pool.

    > This can be enabled by using the new `%i` and `%I` format
    > specifiers for the log file name. See
    > `worker-files-process-index`{.interpreted-text role="ref"}.

-   **Redis**: New experimental chord join implementation.

    > This is an optimization for chords when using the Redis result
    > backend, where the join operation is now considerably faster and
    > using less resources than the previous strategy.
    >
    > The new option can be set in the result backend URL:
    >
    > ``` python
    > CELERY_RESULT_BACKEND = 'redis://localhost?new_join=1'
    > ```
    >
    > This must be enabled manually as it\'s incompatible with workers
    > and clients not using it, so be sure to enable the option in all
    > clients and workers if you decide to use it.

-   **Multi**: With `-opt:index` (e.g., `-c:1`) the index now always
    refers to the position of a node in the argument list.

    > This means that referring to a number will work when specifying a
    > list of node names and not just for a number range:
    >
    > ``` bash
    > celery multi start A B C D -c:1 4 -c:2-4 8
    > ```
    >
    > In this example `1` refers to node A (as it\'s the first node in
    > the list).

-   **Signals**: The sender argument to `Signal.connect` can now be a
    proxy object, which means that it can be used with the task
    decorator (Issue #1873).

-   **Task**: A regression caused the `queue` argument to `Task.retry`
    to be ignored (Issue #1892).

-   **App**: Fixed error message for
    `~@Celery.config_from_envvar`{.interpreted-text role="meth"}.

    > Fix contributed by Dmitry Malinovsky.

-   **Canvas**: Chords can now contain a group of other chords (Issue
    #1921).

-   **Canvas**: Chords can now be combined when using the amqp result
    backend (a chord where the callback is also a chord).

-   **Canvas**: Calling `result.get()` for a chain task will now
    complete even if one of the tasks in the chain is
    `ignore_result=True` (Issue #1905).

-   **Canvas**: Worker now also logs chord errors.

-   **Canvas**: A chord task raising an exception will now result in any
    errbacks (`link_error`) to the chord callback to also be called.

-   **Results**: Reliability improvements to the SQLAlchemy database
    backend (Issue #1786).

    > Previously the connection from the `MainProcess` was improperly
    > inherited by child processes.
    >
    > Fix contributed by Ionel Cristian Mărieș.

-   **Task**: Task callbacks and errbacks are now called using the group
    primitive.

-   **Task**: `Task.apply` now properly sets `request.headers` (Issue
    #1874).

-   **Worker**: Fixed `UnicodeEncodeError`{.interpreted-text role="exc"}
    occurring when worker is started by `supervisor`{.interpreted-text
    role="pypi"}.

    > Fix contributed by Codeb Fan.

-   **Beat**: No longer attempts to upgrade a newly created database
    file (Issue #1923).

-   **Beat**: New setting `` `CELERYBEAT_SYNC_EVERY ``{.interpreted-text
    role="setting"}\` can be be used to control file sync by specifying
    the number of tasks to send between each sync.

    > Contributed by Chris Clark.

-   **Commands**: `celery inspect memdump`{.interpreted-text
    role="program"} no longer crashes if the `psutil`{.interpreted-text
    role="mod"} module isn\'t installed (Issue #1914).

-   **Worker**: Remote control commands now always accepts json
    serialized messages (Issue #1870).

-   **Worker**: Gossip will now drop any task related events it receives
    by mistake (Issue #1882).

## 3.1.9 {#version-3.1.9}

release-date

:   2014-02-10 06:43 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**:

    > -   Now depends on
    >     `Kombu 3.0.12 <kombu:version-3.0.12>`{.interpreted-text
    >     role="ref"}.

-   **Prefork pool**: Better handling of exiting child processes.

    > Fix contributed by Ionel Cristian Mărieș.

-   **Prefork pool**: Now makes sure all file descriptors are removed
    from the hub when a process is cleaned up.

    > Fix contributed by Ionel Cristian Mărieș.

-   **New Sphinx extension**: for autodoc documentation of tasks:
    `celery.contrib.spinx`{.interpreted-text role="mod"} (Issue #1833).

-   **Django**: Now works with Django 1.7a1.

-   **Task**: Task.backend is now a property that forwards to
    `app.backend` if no custom backend has been specified for the task
    (Issue #1821).

-   **Generic init-scripts**: Fixed bug in stop command.

    > Fix contributed by Rinat Shigapov.

-   **Generic init-scripts**: Fixed compatibility with GNU
    `stat`{.interpreted-text role="manpage"}.

    > Fix contributed by Paul Kilgo.

-   **Generic init-scripts**: Fixed compatibility with the minimal
    `dash`{.interpreted-text role="program"} shell (Issue #1815).

-   **Commands**: The `celery amqp basic.publish`{.interpreted-text
    role="program"} command wasn\'t working properly.

    > Fix contributed by Andrey Voronov.

-   **Commands**: Did no longer emit an error message if the pidfile
    exists and the process is still alive (Issue #1855).

-   **Commands**: Better error message for missing arguments to preload
    options (Issue #1860).

-   **Commands**: `celery -h`{.interpreted-text role="program"} didn\'t
    work because of a bug in the argument parser (Issue #1849).

-   **Worker**: Improved error message for message decoding errors.

-   **Time**: Now properly parses the [Z]{.title-ref} timezone specifier
    in ISO 8601 date strings.

    > Fix contributed by Martin Davidsson.

-   **Worker**: Now uses the *negotiated* heartbeat value to calculate
    how often to run the heartbeat checks.

-   **Beat**: Fixed problem with beat hanging after the first schedule
    iteration (Issue #1822).

    > Fix contributed by Roger Hu.

-   **Signals**: The header argument to
    `before_task_publish`{.interpreted-text role="signal"} is now always
    a dictionary instance so that signal handlers can add headers.

-   **Worker**: A list of message headers is now included in message
    related errors.

## 3.1.8 {#version-3.1.8}

release-date

:   2014-01-17 10:45 p.m. UTC

release-by

:   Ask Solem

-   **Requirements**:

    > -   Now depends on
    >     `Kombu 3.0.10 <kombu:version-3.0.10>`{.interpreted-text
    >     role="ref"}.
    > -   Now depends on [billiard
    >     3.3.0.14](https://github.com/celery/billiard/blob/master/CHANGES.txt).

-   **Worker**: The event loop wasn\'t properly reinitialized at
    consumer restart which would force the worker to continue with a
    closed `epoll` instance on Linux, resulting in a crash.

-   **Events:** Fixed issue with both heartbeats and task events that
    could result in the data not being kept in sorted order.

    > As a result this would force the worker to log \"heartbeat
    > missed\" events even though the remote node was sending heartbeats
    > in a timely manner.

-   **Results:** The pickle serializer no longer converts group results
    to tuples, and will keep the original type (*Issue #1750*).

-   **Results:** `ResultSet.iterate` is now pending deprecation.

    > The method will be deprecated in version 3.2 and removed in
    > version 3.3.
    >
    > Use `result.get(callback=)` (or `result.iter_native()` where
    > available) instead.

-   **Worker**\|eventlet/gevent: A regression caused
    `Control-c`{.interpreted-text role="kbd"} to be ineffective for
    shutdown.

-   **Redis result backend:** Now using a pipeline to store state
    changes for improved performance.

    > Contributed by Pepijn de Vos.

-   **Redis result backend:** Will now retry storing the result if
    disconnected.

-   **Worker**\|gossip: Fixed attribute error occurring when another
    node leaves.

    > Fix contributed by Brodie Rao.

-   **Generic init-scripts:** Now runs a check at start-up to verify
    that any configuration scripts are owned by root and that they
    aren\'t world/group writable.

    > The init-script configuration is a shell script executed by root,
    > so this is a preventive measure to ensure that users don\'t leave
    > this file vulnerable to changes by unprivileged users.
    >
    > ::: note
    > ::: title
    > Note
    > :::
    >
    > Note that upgrading Celery won\'t update the init-scripts, instead
    > you need to manually copy the improved versions from the source
    > distribution:
    > <https://github.com/celery/celery/tree/3.1/extra/generic-init.d>
    > :::

-   **Commands**: The `celery purge`{.interpreted-text role="program"}
    command now warns that the operation will delete all tasks and
    prompts the user for confirmation.

    > A new `-f <celery purge -f>`{.interpreted-text role="option"} was
    > added that can be used to disable interactive mode.

-   **Task**: `.retry()` didn\'t raise the value provided in the `exc`
    argument when called outside of an error context (*Issue #1755*).

-   **Commands:** The `celery multi`{.interpreted-text role="program"}
    command didn\'t forward command line configuration to the target
    workers.

    > The change means that multi will forward the special `--` argument
    > and configuration content at the end of the arguments line to the
    > specified workers.
    >
    > Example using command-line configuration to set a broker heartbeat
    > from `celery multi`{.interpreted-text role="program"}:
    >
    > ``` bash
    > $ celery multi start 1 -c3 -- broker.heartbeat=30
    > ```
    >
    > Fix contributed by Antoine Legrand.

-   **Canvas:** `chain.apply_async()` now properly forwards execution
    options.

    > Fix contributed by Konstantin Podshumok.

-   **Redis result backend:** Now takes `connection_pool` argument that
    can be used to change the connection pool class/constructor.

-   **Worker:** Now truncates very long arguments and keyword arguments
    logged by the pool at debug severity.

-   **Worker:** The worker now closes all open files on
    `SIGHUP`{.interpreted-text role="sig"} (regression) (*Issue #1768*).

    > Fix contributed by Brodie Rao

-   **Worker:** Will no longer accept remote control commands while the
    worker start-up phase is incomplete (*Issue #1741*).

-   **Commands:** The output of the event dump utility
    (`celery events -d`{.interpreted-text role="program"}) can now be
    piped into other commands.

-   **Documentation:** The RabbitMQ installation instructions for macOS
    was updated to use modern Homebrew practices.

    > Contributed by Jon Chen.

-   **Commands:** The `celery inspect conf`{.interpreted-text
    role="program"} utility now works.

-   **Commands:** The `--no-color <celery --no-color>`{.interpreted-text
    role="option"} argument was not respected by all commands (*Issue
    #1799*).

-   **App:** Fixed rare bug with `autodiscover_tasks()` (*Issue #1797*).

-   **Distribution:** The sphinx docs will now always add the parent
    directory to path so that the current Celery source code is used as
    a basis for API documentation (*Issue #1782*).

-   **Documentation:** `supervisor`{.interpreted-text role="pypi"}
    examples contained an extraneous \'-\' in a
    `--logfile <celery worker --logfile>`{.interpreted-text
    role="option"} argument example.

    > Fix contributed by Mohammad Almeer.

## 3.1.7 {#version-3.1.7}

release-date

:   2013-12-17 06:00 p.m. UTC

release-by

:   Ask Solem

### Important Notes {#v317-important}

### Init-script security improvements

Where the generic init-scripts (for `celeryd`, and `celerybeat`) before
delegated the responsibility of dropping privileges to the target
application, it will now use `su` instead, so that the Python program
isn\'t trusted with superuser privileges.

This isn\'t in reaction to any known exploit, but it will limit the
possibility of a privilege escalation bug being abused in the future.

You have to upgrade the init-scripts manually from this directory:
<https://github.com/celery/celery/tree/3.1/extra/generic-init.d>

#### AMQP result backend

The 3.1 release accidentally left the amqp backend configured to be
non-persistent by default.

Upgrading from 3.0 would give a \"not equivalent\" error when attempting
to set or retrieve results for a task. That\'s unless you manually set
the persistence setting:

    CELERY_RESULT_PERSISTENT = True

This version restores the previous value so if you already forced the
upgrade by removing the existing exchange you must either keep the
configuration by setting `CELERY_RESULT_PERSISTENT = False` or delete
the `celeryresults` exchange again.

#### Synchronous subtasks

Tasks waiting for the result of a subtask will now emit a
`RuntimeWarning`{.interpreted-text role="exc"} warning when using the
prefork pool, and in 3.2 this will result in an exception being raised.

It\'s not legal for tasks to block by waiting for subtasks as this is
likely to lead to resource starvation and eventually deadlock when using
the prefork pool (see also `task-synchronous-subtasks`{.interpreted-text
role="ref"}).

If you really know what you\'re doing you can avoid the warning (and the
future exception being raised) by moving the operation in a white-list
block:

``` python
from celery.result import allow_join_result

@app.task
def misbehaving():
    result = other_task.delay()
    with allow_join_result():
        result.get()
```

Note also that if you wait for the result of a subtask in any form when
using the prefork pool you must also disable the pool prefetching
behavior with the worker
`-Ofair option <optimizing-prefetch-limit>`{.interpreted-text
role="ref"}.

### Fixes {#v317-fixes}

-   Now depends on `Kombu 3.0.8 <kombu:version-3.0.8>`{.interpreted-text
    role="ref"}.

-   Now depends on `billiard`{.interpreted-text role="mod"} 3.3.0.13

-   Events: Fixed compatibility with non-standard json libraries that
    sends float as `decimal.Decimal`{.interpreted-text role="class"}
    (Issue #1731)

-   Events: State worker objects now always defines attributes:
    `active`, `processed`, `loadavg`, `sw_ident`, `sw_ver` and `sw_sys`.

-   Worker: Now keeps count of the total number of tasks processed, not
    just by type (`all_active_count`).

-   Init-scripts: Fixed problem with reading configuration file when the
    init-script is symlinked to a runlevel (e.g., `S02celeryd`). (Issue
    #1740).

    > This also removed a rarely used feature where you can symlink the
    > script to provide alternative configurations. You instead copy the
    > script and give it a new name, but perhaps a better solution is to
    > provide arguments to `CELERYD_OPTS` to separate them:
    >
    > ``` bash
    > CELERYD_NODES="X1 X2 Y1 Y2"
    > CELERYD_OPTS="-A:X1 x -A:X2 x -A:Y1 y -A:Y2 y"
    > ```

-   Fallback chord unlock task is now always called after the chord
    header (Issue #1700).

    > This means that the unlock task won\'t be started if there\'s an
    > error sending the header.

-   Celery command: Fixed problem with arguments for some control
    commands.

    > Fix contributed by Konstantin Podshumok.

-   Fixed bug in `utcoffset` where the offset when in DST would be
    completely wrong (Issue #1743).

-   Worker: Errors occurring while attempting to serialize the result of
    a task will now cause the task to be marked with failure and a
    `kombu.exceptions.EncodingError`{.interpreted-text role="class"}
    error.

    > Fix contributed by Ionel Cristian Mărieș.

-   Worker with `-B <celery worker -B>`{.interpreted-text role="option"}
    argument didn\'t properly shut down the beat instance.

-   Worker: The `%n` and `%h` formats are now also supported by the
    `--logfile <celery worker --logfile>`{.interpreted-text
    role="option"},
    `--pidfile <celery worker --pidfile>`{.interpreted-text
    role="option"} and
    `--statedb <celery worker --statedb>`{.interpreted-text
    role="option"} arguments.

    > Example:
    >
    > ``` bash
    > $ celery -A proj worker -n foo@%h --logfile=%n.log --statedb=%n.db
    > ```

-   Redis/Cache result backends: Will now timeout if keys evicted while
    trying to join a chord.

-   The fallback unlock chord task now raises `Retry`{.interpreted-text
    role="exc"} so that the retry even is properly logged by the worker.

-   Multi: Will no longer apply Eventlet/gevent monkey patches (Issue
    #1717).

-   Redis result backend: Now supports UNIX sockets.

    > Like the Redis broker transport the result backend now also
    > supports using `redis+socket:///tmp/redis.sock` URLs.
    >
    > Contributed by Alcides Viamontes Esquivel.

-   Events: Events sent by clients was mistaken for worker related
    events (Issue #1714).

    > For `events.State` the tasks now have a `Task.client` attribute
    > that\'s set when a `task-sent` event is being received.
    >
    > Also, a clients logical clock isn\'t in sync with the cluster so
    > they live in a \"time bubble.\" So for this reason monitors will
    > no longer attempt to merge with the clock of an event sent by a
    > client, instead it will fake the value by using the current clock
    > with a skew of -1.

-   Prefork pool: The method used to find terminated processes was
    flawed in that it didn\'t also take into account missing `popen`
    objects.

-   Canvas: `group` and `chord` now works with anon signatures as long
    as the group/chord object is associated with an app instance (Issue
    #1744).

    > You can pass the app by using `group(..., app=app)`.

## 3.1.6 {#version-3.1.6}

release-date

:   2013-12-02 06:00 p.m. UTC

release-by

:   Ask Solem

-   Now depends on `billiard`{.interpreted-text role="mod"} 3.3.0.10.

-   Now depends on `Kombu 3.0.7 <kombu:version-3.0.7>`{.interpreted-text
    role="ref"}.

-   Fixed problem where Mingle caused the worker to hang at start-up
    (Issue #1686).

-   Beat: Would attempt to drop privileges twice (Issue #1708).

-   Windows: Fixed error with `geteuid` not being available (Issue
    #1676).

-   Tasks can now provide a list of expected error classes (Issue
    #1682).

    > The list should only include errors that the task is expected to
    > raise during normal operation:
    >
    >     @task(throws=(KeyError, HttpNotFound))
    >
    > What happens when an exceptions is raised depends on the type of
    > error:
    >
    > -   Expected errors (included in `Task.throws`)
    >
    >     > Will be logged using severity `INFO`, and traceback is
    >     > excluded.
    >
    > -   Unexpected errors
    >
    >     > Will be logged using severity `ERROR`, with traceback
    >     > included.

-   Cache result backend now compatible with Python 3 (Issue #1697).

-   CentOS init-script: Now compatible with SysV style init symlinks.

    > Fix contributed by Jonathan Jordan.

-   Events: Fixed problem when task name isn\'t defined (Issue #1710).

    > Fix contributed by Mher Movsisyan.

-   Task: Fixed unbound local errors (Issue #1684).

    > Fix contributed by Markus Ullmann.

-   Canvas: Now unrolls groups with only one task (optimization) (Issue
    #1656).

-   Task: Fixed problem with ETA and timezones.

    > Fix contributed by Alexander Koval.

-   Django: Worker now performs model validation (Issue #1681).

-   Task decorator now emits less confusing errors when used with
    incorrect arguments (Issue #1692).

-   Task: New method `Task.send_event` can be used to send custom events
    to Flower and other monitors.

-   Fixed a compatibility issue with non-abstract task classes

-   Events from clients now uses new node name format
    (`gen<pid>@<hostname>`).

-   Fixed rare bug with Callable not being defined at interpreter
    shutdown (Issue #1678).

    > Fix contributed by Nick Johnson.

-   Fixed Python 2.6 compatibility (Issue #1679).

## 3.1.5 {#version-3.1.5}

release-date

:   2013-11-21 06:20 p.m. UTC

release-by

:   Ask Solem

-   Now depends on `Kombu 3.0.6 <kombu:version-3.0.6>`{.interpreted-text
    role="ref"}.

-   Now depends on `billiard`{.interpreted-text role="mod"} 3.3.0.8

-   App: `config_from_object` is now lazy (Issue #1665).

-   App: `autodiscover_tasks` is now lazy.

    > Django users should now wrap access to the settings object in a
    > lambda:
    >
    >     app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)
    >
    > this ensures that the settings object isn\'t prepared prematurely.

-   Fixed regression for `--app <celery --app>`{.interpreted-text
    role="option"} argument experienced by some users (Issue #1653).

-   Worker: Now respects the
    `--uid <celery worker --uid>`{.interpreted-text role="option"} and
    `--gid <celery worker --gid>`{.interpreted-text role="option"}
    arguments even if
    `--detach <celery worker --detach>`{.interpreted-text role="option"}
    isn\'t enabled.

-   Beat: Now respects the `--uid <celery beat --uid>`{.interpreted-text
    role="option"} and `--gid <celery beat --gid>`{.interpreted-text
    role="option"} arguments even if
    `--detach <celery beat --detach>`{.interpreted-text role="option"}
    isn\'t enabled.

-   Python 3: Fixed unorderable error occurring with the worker
    `-B <celery worker -B>`{.interpreted-text role="option"} argument
    enabled.

-   `celery.VERSION` is now a named tuple.

-   `maybe_signature(list)` is now applied recursively (Issue #1645).

-   `celery shell` command: Fixed `IPython.frontend` deprecation
    warning.

-   The default app no longer includes the built-in fix-ups.

    > This fixes a bug where `celery multi` would attempt to load the
    > Django settings module before entering the target working
    > directory.

-   The Django daemonization tutorial was changed.

    > Users no longer have to explicitly export `DJANGO_SETTINGS_MODULE`
    > in `/etc/default/celeryd`{.interpreted-text role="file"} when the
    > new project layout is used.

-   Redis result backend: expiry value can now be 0 (Issue #1661).

-   Censoring settings now accounts for non-string keys (Issue #1663).

-   App: New `autofinalize` option.

    > Apps are automatically finalized when the task registry is
    > accessed. You can now disable this behavior so that an exception
    > is raised instead.
    >
    > Example:
    >
    > ``` python
    > app = Celery(autofinalize=False)
    >
    > # raises RuntimeError
    > tasks = app.tasks
    >
    > @app.task
    > def add(x, y):
    >     return x + y
    >
    > # raises RuntimeError
    > add.delay(2, 2)
    >
    > app.finalize()
    > # no longer raises:
    > tasks = app.tasks
    > add.delay(2, 2)
    > ```

-   The worker didn\'t send monitoring events during shutdown.

-   Worker: Mingle and gossip is now automatically disabled when used
    with an unsupported transport (Issue #1664).

-   `celery` command: Preload options now supports the rare
    `--opt value` format (Issue #1668).

-   `celery` command: Accidentally removed options appearing before the
    sub-command, these are now moved to the end instead.

-   Worker now properly responds to `inspect stats` commands even if
    received before start-up is complete (Issue #1659).

-   `task_postrun`{.interpreted-text role="signal"} is now sent within a
    `finally`{.interpreted-text role="keyword"} block, to make sure the
    signal is always sent.

-   Beat: Fixed syntax error in string formatting.

    > Contributed by `nadad`{.interpreted-text role="github_user"}.

-   Fixed typos in the documentation.

    > Fixes contributed by Loic Bistuer, `sunfinite`{.interpreted-text
    > role="github_user"}.

-   Nested chains now works properly when constructed using the `chain`
    type instead of the `|` operator (Issue #1656).

## 3.1.4 {#version-3.1.4}

release-date

:   2013-11-15 11:40 p.m. UTC

release-by

:   Ask Solem

-   Now depends on `Kombu 3.0.5 <kombu:version-3.0.5>`{.interpreted-text
    role="ref"}.

-   Now depends on `billiard`{.interpreted-text role="mod"} 3.3.0.7

-   Worker accidentally set a default socket timeout of 5 seconds.

-   Django: Fix-up now sets the default app so that threads will use the
    same app instance (e.g., for `manage.py runserver`{.interpreted-text
    role="command"}).

-   Worker: Fixed Unicode error crash at start-up experienced by some
    users.

-   Calling `.apply_async` on an empty chain now works again (Issue
    #1650).

-   The `celery multi show` command now generates the same arguments as
    the start command does.

-   The `--app <celery --app>`{.interpreted-text role="option"} argument
    could end up using a module object instead of an app instance (with
    a resulting crash).

-   Fixed a syntax error problem in the beat init-script.

    > Fix contributed by Vsevolod.

-   Tests now passing on PyPy 2.1 and 2.2.

## 3.1.3 {#version-3.1.3}

release-date

:   2013-11-13 00:55 a.m. UTC

release-by

:   Ask Solem

-   Fixed compatibility problem with Python 2.7.0 - 2.7.5 (Issue #1637)

    > `unpack_from` started supporting `memoryview` arguments in Python
    > 2.7.6.

-   Worker: `-B <celery worker -B>`{.interpreted-text role="option"}
    argument accidentally closed files used for logging.

-   Task decorated tasks now keep their docstring (Issue #1636)

## 3.1.2 {#version-3.1.2}

release-date

:   2013-11-12 08:00 p.m. UTC

release-by

:   Ask Solem

-   Now depends on `billiard`{.interpreted-text role="mod"} 3.3.0.6

-   No longer needs the billiard C extension to be installed.

-   The worker silently ignored task errors.

-   Django: Fixed `ImproperlyConfigured` error raised when no database
    backend specified.

    > Fix contributed by `j0hnsmith`{.interpreted-text
    > role="github_user"}.

-   Prefork pool: Now using `_multiprocessing.read` with `memoryview` if
    available.

-   `close_open_fds` now uses `os.closerange` if available.

-   `get_fdmax` now takes value from `sysconfig` if possible.

## 3.1.1 {#version-3.1.1}

release-date

:   2013-11-11 06:30 p.m. UTC

release-by

:   Ask Solem

-   Now depends on `billiard`{.interpreted-text role="mod"} 3.3.0.4.

-   Python 3: Fixed compatibility issues.

-   Windows: Accidentally showed warning that the billiard C extension
    wasn\'t installed (Issue #1630).

-   Django: Tutorial updated with a solution that sets a default
    `DJANGO_SETTINGS_MODULE`{.interpreted-text role="envvar"} so that it
    doesn\'t have to be typed in with the `celery`{.interpreted-text
    role="program"} command.

    > Also fixed typos in the tutorial, and added the settings required
    > to use the Django database backend.
    >
    > Thanks to Chris Ward, `orarbel`{.interpreted-text
    > role="github_user"}.

-   Django: Fixed a problem when using the Django settings in Django
    1.6.

-   Django: Fix-up shouldn\'t be applied if the django loader is active.

-   Worker: Fixed attribute error for `human_write_stats` when using the
    compatibility prefork pool implementation.

-   Worker: Fixed compatibility with billiard without C extension.

-   Inspect.conf: Now supports a `with_defaults` argument.

-   Group.restore: The backend argument wasn\'t respected.

## 3.1.0 {#version-3.1.0}

release-date

:   2013-11-09 11:00 p.m. UTC

release-by

:   Ask Solem

See `whatsnew-3.1`{.interpreted-text role="ref"}.