celery/Changelog

==============
Change history
==============

0.8.0 [2009-09-22 03:06 P.M CET]
--------------------------------

**BACKWARD INCOMPATIBLE CHANGES**

* Add traceback to result value on failure.
	**NOTE** If you use the database backend you have to re-create the
	database table ``celery_taskmeta``.
	
	Contact the mailinglist or IRC channel listed in README for help
	doing this.

* Database tables are now only created if the database backend is used,
	so if you change back to the database backend at some point,
	be sure to initialize tables (django: ``syncdb``, python: ``celeryinit``).
	(Note: This is only the case when using Django 1.1 or higher)

* Now depends on ``carrot`` version 0.6.0.

* Now depends on python-daemon 1.4.8

**IMPORTANT CHANGES**

* Celery can now be used in pure Python (outside of a Django project).
	This means celery is no longer Django specific.
	
	For more information see the FAQ entry
	`Can I use celery without Django?`_.

.. _`Can I use celery without Django?`:
	http://ask.github.com/celery/faq.html#can-i-use-celery-without-django

* Celery now supports task retries.

	See `Cookbook: Retrying Tasks`_ for more information.

.. _`Cookbook: Retrying Tasks`:
	http://ask.github.com/celery/cookbook/task-retries.html

* We now have an AMQP result store backend.

	It uses messages to publish task return value and status. And it's
	incredibly fast!

	See http://github.com/ask/celery/issues/closed#issue/6 for more info!

* AMQP QoS (prefetch count) implemented:
	This to not receive more messages than we can handle.

* Now redirects stdout/stderr to the celeryd logfile when detached 

* Now uses ``inspect.getargspec`` to only pass default arguments
	the task supports.

* Add Task.on_success, .on_retry, .on_failure handlers
	See :meth:`celery.task.base.Task.on_success`,
	    :meth:`celery.task.base.Task.on_retry`,
	    	:meth:`celery.task.base.Task.on_failure`,

* ``celery.utils.gen_unique_id``: Workaround for
	http://bugs.python.org/issue4607

* You can now customize what happens at worker start, at process init, etc
	by creating your own loaders. (see :mod:`celery.loaders.default`,
	:mod:`celery.loaders.djangoapp`, :mod:`celery.loaders`.)

* Support for multiple AMQP exchanges and queues.

	This feature misses documentation and tests, so anyone interested 
	is encouraged to improve this situation.

* celeryd now survives a restart of the AMQP server!

  Automatically re-establish AMQP broker connection if it's lost.

  New settings:

    * AMQP_CONNECTION_RETRY
        Set to ``True`` to enable connection retries.

    * AMQP_CONNECTION_MAX_RETRIES.
        Maximum number of restarts before we give up. Default: ``100``.

**NEWS**

*  Fix an incompatibility between python-daemon and multiprocessing,
	which resulted in the ``[Errno 10] No child processes`` problem when
	detaching.

* Fixed a possible DjangoUnicodeDecodeError being raised when saving pickled
	data to Django's memcached cache backend.

* Better Windows compatibility.

* New version of the pickled field (taken from
	http://www.djangosnippets.org/snippets/513/)

* New signals introduced: ``task_sent``, ``task_prerun`` and
	``task_postrun``, see :mod:`celery.signals` for more information.

* ``TaskSetResult.join`` caused ``TypeError`` when ``timeout=None``.
	Thanks Jerzy Kozera.  Closes #31

* ``views.apply`` should return ``HttpResponse`` instance.
	Thanks to Jerzy Kozera. Closes #32

* ``PeriodicTask``: Save conversion of ``run_every`` from ``int``
	to ``timedelta`` to the class attribute instead of on the instance.

* Exceptions has been moved to ``celery.exceptions``, but are still
	available in the previous module.

* Try to rollback transaction and retry saving result if an error happens
	while setting task status with the database backend.

* jail() refactored into :class:`celery.execute.ExecuteWrapper`.

* ``views.apply`` now correctly sets mimetype to "application/json"

* ``views.task_status`` now returns exception if status is RETRY

* ``views.task_status`` now returns traceback if status is "FAILURE"
	or "RETRY"

* Documented default task arguments.

* Add a sensible __repr__ to ExceptionInfo for easier debugging

* Fix documentation typo ``.. import map`` -> ``.. import dmap``.
	Thanks mikedizon

0.6.0 [2009-08-07 06:54 A.M CET]
--------------------------------

**IMPORTANT CHANGES**

* Fixed a bug where tasks raising unpickleable exceptions crashed pool
	workers. So if you've had pool workers mysteriously dissapearing, or
	problems with celeryd stopping working, this has been fixed in this
	version.

* Fixed a race condition with periodic tasks.

* The task pool is now supervised, so if a pool worker crashes,
	goes away or stops responding, it is automatically replaced with
	a new one.

* Task.name is now automatically generated out of class module+name, e.g.
	``"djangotwitter.tasks.UpdateStatusesTask"``. Very convenient. No idea why
	we didn't do this before. Some documentation is updated to not manually
	specify a task name.

**NEWS**

* Tested with Django 1.1

* New Tutorial: Creating a click counter using carrot and celery

* Database entries for periodic tasks are now created at ``celeryd``
	startup instead of for each check (which has been a forgotten TODO/XXX
	in the code for a long time)

* New settings variable: ``CELERY_TASK_RESULT_EXPIRES``
	Time (in seconds, or a `datetime.timedelta` object) for when after
	stored task results are deleted. For the moment this only works for the
	database backend.

* ``celeryd`` now emits a debug log message for which periodic tasks
	has been launched.

* The periodic task table is now locked for reading while getting
	periodic task status. (MySQL only so far, seeking patches for other
	engines)

* A lot more debugging information is now available by turning on the
	``DEBUG`` loglevel (``--loglevel=DEBUG``).

* Functions/methods with a timeout argument now works correctly.

* New: ``celery.strategy.even_time_distribution``: 
	With an iterator yielding task args, kwargs tuples, evenly distribute
	the processing of its tasks throughout the time window available.

* Log message ``Unknown task ignored...`` now has loglevel ``ERROR``

* Log message ``"Got task from broker"`` is now emitted for all tasks, even if
	the task has an ETA (estimated time of arrival). Also the message now
	includes the ETA for the task (if any).

* Acknowledgement now happens in the pool callback. Can't do ack in the job
	target, as it's not pickleable (can't share AMQP connection, etc)).

* Added note about .delay hanging in README

* Tests now passing in Django 1.1

* Fixed discovery to make sure app is in INSTALLED_APPS

* Previously overrided pool behaviour (process reap, wait until pool worker
	available, etc.) is now handled by ``multiprocessing.Pool`` itself.

* Convert statistics data to unicode for use as kwargs. Thanks Lucy!

0.4.1 [2009-07-02 01:42 P.M CET]
--------------------------------

* Fixed a bug with parsing the message options (``mandatory``,
  ``routing_key``, ``priority``, ``immediate``)

0.4.0 [2009-07-01 07:29 P.M CET] 
--------------------------------

* Adds eager execution. ``celery.execute.apply``|``Task.apply`` executes the
  function blocking until the task is done, for API compatiblity it
  returns an ``celery.result.EagerResult`` instance. You can configure
  celery to always run tasks locally by setting the
  ``CELERY_ALWAYS_EAGER`` setting to ``True``.

* Now depends on ``anyjson``.

* 99% coverage using python ``coverage`` 3.0.

0.3.20 [2009-06-25 08:42 P.M CET] 
---------------------------------

* New arguments to ``apply_async`` (the advanced version of
  ``delay_task``), ``countdown`` and ``eta``;

	>>> # Run 10 seconds into the future.
	>>> res = apply_async(MyTask, countdown=10);

	>>> # Run 1 day from now
	>>> res = apply_async(MyTask, eta=datetime.now() + 
	...									timedelta(days=1)

* Now unlinks the pidfile if it's stale.

* Lots of more tests.

* Now compatible with carrot >= 0.5.0.

* **IMPORTANT** The ``subtask_ids`` attribute on the ``TaskSetResult``
  instance has been removed. To get this information instead use:

		>>> subtask_ids = [subtask.task_id for subtask in ts_res.subtasks]

*	``Taskset.run()`` now respects extra message options from the task class.

* Task: Add attribute ``ignore_result``: Don't store the status and
  return value. This means you can't use the
  ``celery.result.AsyncResult`` to check if the task is
  done, or get its return value. Only use if you need the performance
  and is able live without these features. Any exceptions raised will
  store the return value/status as usual.

* Task: Add attribute ``disable_error_emails`` to disable sending error
  emails for that task.

* Should now work on Windows (although running in the background won't
  work, so using the ``--detach`` argument results in an exception
  being raised.)

* Added support for statistics for profiling and monitoring.
  To start sending statistics start ``celeryd`` with the
  ``--statistics`` option. Then after a while you can dump the results
  by running ``python manage.py celerystats``. See
  ``celery.monitoring`` for more information.

* The celery daemon can now be supervised (i.e it is automatically
  restarted if it crashes). To use this start celeryd with the
  ``--supervised`` option (or alternatively ``-S``).

* views.apply: View applying a task. Example::

	http://e.com/celery/apply/task_name/arg1/arg2//?kwarg1=a&kwarg2=b

  **NOTE** Use with caution, preferably not make this publicly
  accessible without ensuring your code is safe!

* Refactored ``celery.task``. It's now split into three modules:

	* celery.task

		Contains ``apply_async``, ``delay_task``, ``discard_all``, and task
		shortcuts, plus imports objects from ``celery.task.base`` and
		``celery.task.builtins``

	* celery.task.base

		Contains task base classes: ``Task``, ``PeriodicTask``,
		``TaskSet``, ``AsynchronousMapTask``, ``ExecuteRemoteTask``.

	* celery.task.builtins

		Built-in tasks: ``PingTask``, ``DeleteExpiredTaskMetaTask``.


0.3.7 [2008-06-16 11:41 P.M CET] 
--------------------------------

* **IMPORTANT** Now uses AMQP's ``basic.consume`` instead of
  ``basic.get``. This means we're no longer polling the broker for
  new messages.

* **IMPORTANT** Default concurrency limit is now set to the number of CPUs
  available on the system.

* **IMPORTANT** ``tasks.register``: Renamed ``task_name`` argument to
  ``name``, so

		>>> tasks.register(func, task_name="mytask")

  has to be replaced with:

		>>> tasks.register(func, name="mytask")

* The daemon now correctly runs if the pidlock is stale.

* Now compatible with carrot 0.4.5

* Default AMQP connnection timeout is now 4 seconds.
* ``AsyncResult.read()`` was always returning ``True``.

*  Only use README as long_description if the file exists so easy_install
   doesn't break.

* ``celery.view``: JSON responses now properly set its mime-type. 

* ``apply_async`` now has a ``connection`` keyword argument so you
  can re-use the same AMQP connection if you want to execute
  more than one task.

* Handle failures in task_status view such that it won't throw 500s.

* Fixed typo ``AMQP_SERVER`` in documentation to ``AMQP_HOST``.

* Worker exception e-mails sent to admins now works properly.

* No longer depends on ``django``, so installing ``celery`` won't affect
  the preferred Django version installed.

* Now works with PostgreSQL (psycopg2) again by registering the
  ``PickledObject`` field.

* ``celeryd``: Added ``--detach`` option as an alias to ``--daemon``, and
  it's the term used in the documentation from now on.

* Make sure the pool and periodic task worker thread is terminated
  properly at exit. (So ``Ctrl-C`` works again).

* Now depends on ``python-daemon``.

* Removed dependency to ``simplejson``

* Cache Backend: Re-establishes connection for every task process
  if the Django cache backend is memcached/libmemcached.

* Tyrant Backend: Now re-establishes the connection for every task
  executed.

0.3.3 [2009-06-08 01:07 P.M CET] 
--------------------------------

	* The ``PeriodicWorkController`` now sleeps for 1 second between checking
		for periodic tasks to execute.

0.3.2 [2009-06-08 01:07 P.M CET]
--------------------------------

* celeryd: Added option ``--discard``: Discard (delete!) all waiting
  messages in the queue.

* celeryd: The ``--wakeup-after`` option was not handled as a float.

0.3.1 [2009-06-08 01:07 P.M CET]
--------------------------------

* The `PeriodicTask`` worker is now running in its own thread instead
  of blocking the ``TaskController`` loop.

* Default ``QUEUE_WAKEUP_AFTER`` has been lowered to ``0.1`` (was ``0.3``)

0.3.0 [2009-06-08 12:41 P.M CET]
--------------------------------

**NOTE** This is a development version, for the stable release, please
see versions 0.2.x.

**VERY IMPORTANT:** Pickle is now the encoder used for serializing task
arguments, so be sure to flush your task queue before you upgrade.

* **IMPORTANT** TaskSet.run() now returns a celery.result.TaskSetResult
  instance, which lets you inspect the status and return values of a
  taskset as it was a single entity.

* **IMPORTANT** Celery now depends on carrot >= 0.4.1.

* The celery daemon now sends task errors to the registered admin e-mails.
  To turn off this feature, set ``SEND_CELERY_TASK_ERROR_EMAILS`` to
  ``False`` in your ``settings.py``. Thanks to Grégoire Cachet.

* You can now run the celery daemon by using ``manage.py``::

		$ python manage.py celeryd

  Thanks to Grégoire Cachet.

* Added support for message priorities, topic exchanges, custom routing
  keys for tasks. This means we have introduced
  ``celery.task.apply_async``, a new way of executing tasks.

  You can use ``celery.task.delay`` and ``celery.Task.delay`` like usual, but
  if you want greater control over the message sent, you want
  ``celery.task.apply_async`` and ``celery.Task.apply_async``.

  This also means the AMQP configuration has changed. Some settings has
  been renamed, while others are new::

		CELERY_AMQP_EXCHANGE
		CELERY_AMQP_PUBLISHER_ROUTING_KEY
		CELERY_AMQP_CONSUMER_ROUTING_KEY
		CELERY_AMQP_CONSUMER_QUEUE
		CELERY_AMQP_EXCHANGE_TYPE

  See the entry `Can I send some tasks to only some servers?`_ in the
  `FAQ`_ for more information.

.. _`Can I send some tasks to only some servers?`:
		http://bit.ly/celery_AMQP_routing
.. _`FAQ`: http://ask.github.com/celery/faq.html

* Task errors are now logged using loglevel ``ERROR`` instead of ``INFO``,
  and backtraces are dumped. Thanks to Grégoire Cachet.

* Make every new worker process re-establish it's Django DB connection,
  this solving the "MySQL connection died?" exceptions.
  Thanks to Vitaly Babiy and Jirka Vejrazka.

* **IMOPORTANT** Now using pickle to encode task arguments. This means you
  now can pass complex python objects to tasks as arguments.

* Removed dependency to ``yadayada``.

* Added a FAQ, see ``docs/faq.rst``.

* Now converts any unicode keys in task ``kwargs`` to regular strings.
  Thanks Vitaly Babiy.

* Renamed the ``TaskDaemon`` to ``WorkController``.

* ``celery.datastructures.TaskProcessQueue`` is now renamed to
  ``celery.pool.TaskPool``.

* The pool algorithm has been refactored for greater performance and
  stability.

0.2.0 [2009-05-20 05:14 P.M CET]
--------------------------------

* Final release of 0.2.0

* Compatible with carrot version 0.4.0.

* Fixes some syntax errors related to fetching results
  from the database backend.

0.2.0-pre3 [2009-05-20 05:14 P.M CET]
-------------------------------------

* *Internal release*. Improved handling of unpickled exceptions,
  ``get_result`` now tries to recreate something looking like the
  original exception.

0.2.0-pre2 [2009-05-20 01:56 P.M CET]
-------------------------------------

* Now handles unpickleable exceptions (like the dynimically generated
  subclasses of ``django.core.exception.MultipleObjectsReturned``).

0.2.0-pre1 [2009-05-20 12:33 P.M CET]
-------------------------------------

* It's getting quite stable, with a lot of new features, so bump
  version to 0.2. This is a pre-release.

* ``celery.task.mark_as_read()`` and ``celery.task.mark_as_failure()`` has
  been removed. Use ``celery.backends.default_backend.mark_as_read()``, 
  and ``celery.backends.default_backend.mark_as_failure()`` instead.

0.1.15 [2009-05-19 04:13 P.M CET]
---------------------------------

* The celery daemon was leaking AMQP connections, this should be fixed,
  if you have any problems with too many files open (like ``emfile``
  errors in ``rabbit.log``, please contact us!

0.1.14 [2009-05-19 01:08 P.M CET]
---------------------------------

* Fixed a syntax error in the ``TaskSet`` class.  (No such variable
  ``TimeOutError``).

0.1.13 [2009-05-19 12:36 P.M CET]
---------------------------------

* Forgot to add ``yadayada`` to install requirements.

* Now deletes all expired task results, not just those marked as done.

* Able to load the Tokyo Tyrant backend class without django
  configuration, can specify tyrant settings directly in the class
  constructor.

* Improved API documentation

* Now using the Sphinx documentation system, you can build
  the html documentation by doing ::

		$ cd docs
		$ make html

  and the result will be in ``docs/.build/html``.

0.1.12 [2009-05-18 04:38 P.M CET]
---------------------------------

* ``delay_task()`` etc. now returns ``celery.task.AsyncResult`` object,
  which lets you check the result and any failure that might have
  happened.  It kind of works like the ``multiprocessing.AsyncResult``
  class returned by ``multiprocessing.Pool.map_async``.

* Added dmap() and dmap_async(). This works like the 
  ``multiprocessing.Pool`` versions except they are tasks
  distributed to the celery server. Example:

		>>> from celery.task import dmap
		>>> import operator
		>>> dmap(operator.add, [[2, 2], [4, 4], [8, 8]])
		>>> [4, 8, 16]
        
		>>> from celery.task import dmap_async
		>>> import operator
		>>> result = dmap_async(operator.add, [[2, 2], [4, 4], [8, 8]])
		>>> result.ready()
		False
		>>> time.sleep(1)
		>>> result.ready()
		True
		>>> result.result
		[4, 8, 16]

* Refactored the task metadata cache and database backends, and added
  a new backend for Tokyo Tyrant. You can set the backend in your django
  settings file. e.g::

		CELERY_BACKEND = "database"; # Uses the database
		CELERY_BACKEND = "cache"; # Uses the django cache framework
		CELERY_BACKEND = "tyrant"; # Uses Tokyo Tyrant
		TT_HOST = "localhost"; # Hostname for the Tokyo Tyrant server.
		TT_PORT = 6657; # Port of the Tokyo Tyrant server.

0.1.11 [2009-05-12 02:08 P.M CET]
---------------------------------

* The logging system was leaking file descriptors, resulting in
  servers stopping with the EMFILES (too many open files) error. (fixed)

0.1.10 [2009-05-11 12:46 P.M CET]
---------------------------------

* Tasks now supports both positional arguments and keyword arguments.

* Requires carrot 0.3.8.

* The daemon now tries to reconnect if the connection is lost.

0.1.8 [2009-05-07 12:27 P.M CET]
--------------------------------

* Better test coverage
* More documentation
* celeryd doesn't emit ``Queue is empty`` message if
  ``settings.CELERYD_EMPTY_MSG_EMIT_EVERY`` is 0.

0.1.7 [2009-04-30 1:50 P.M CET]
-------------------------------

* Added some unittests

* Can now use the database for task metadata (like if the task has
  been executed or not). Set ``settings.CELERY_TASK_META``

* Can now run ``python setup.py test`` to run the unittests from
  within the ``testproj`` project.

* Can set the AMQP exchange/routing key/queue using
  ``settings.CELERY_AMQP_EXCHANGE``, ``settings.CELERY_AMQP_ROUTING_KEY``,
  and ``settings.CELERY_AMQP_CONSUMER_QUEUE``.

0.1.6 [2009-04-28 2:13 P.M CET]
-------------------------------

* Introducing ``TaskSet``. A set of subtasks is executed and you can
  find out how many, or if all them, are done (excellent for progress
  bars and such)

* Now catches all exceptions when running ``Task.__call__``, so the
  daemon doesn't die. This does't happen for pure functions yet, only
  ``Task`` classes.

* ``autodiscover()`` now works with zipped eggs.

* celeryd: Now adds curernt working directory to ``sys.path`` for
  convenience.

* The ``run_every`` attribute of ``PeriodicTask`` classes can now be a
  ``datetime.timedelta()`` object.

* celeryd: You can now set the ``DJANGO_PROJECT_DIR`` variable
  for ``celeryd`` and it will add that to ``sys.path`` for easy launching.

* Can now check if a task has been executed or not via HTTP.

* You can do this by including the celery ``urls.py`` into your project,

		>>> url(r'^celery/$', include("celery.urls"))

  then visiting the following url,::

		http://mysite/celery/$task_id/done/

  this will return a JSON dictionary like e.g:

		>>> {"task": {"id": $task_id, "executed": true}}

* ``delay_task`` now returns string id, not ``uuid.UUID`` instance.

* Now has ``PeriodicTasks``, to have ``cron`` like functionality.

* Project changed name from ``crunchy`` to ``celery``. The details of
  the name change request is in ``docs/name_change_request.txt``.

0.1.0 [2009-04-24 11:28 A.M CET]
--------------------------------

* Initial release