python – 使用Celery与SQLAlchemy和Pyramid

我正在使用Pyramid-1.2.1创建Web应用程序,sqlAlchemy作为数据库后端.
现在我需要和这个应用程序一起做一些周期性的任务,我想使用Celery作为任务处理器,sqlAlchemy作为消息队列和结果后端.

1)我已经安装了Celery-2.1.4,但我无法弄清楚如何使它工作.这是我的celeryconfig.py文件：

# List of modules to import when celery starts.
CELERY_IMPORTS = ("my_app.tasks",)

## Result store settings.
CELERY_RESULT_BACKEND = "database"
CELERY_RESULT_DBURI = "sqlite:///MyDataBase.db"
CELERY_RESULT_SERIALIZER = "json"

## broker settings.
broKER_TRANSPORT = "sqlakombu.transport.Transport"
broKER_HOST = "sqlite:///MyDataBase.db"

my_app.tasks包含来自芹菜示例的简单添加任务.
现在我跑的时候

$celeryd -l info

我看到以下内容：

[2011-11-11 20:22:50,750: WARNING/MainProcess] [e-mail] v2.1.4 is starting.
[2011-11-11 20:22:50,765: WARNING/MainProcess]  
Configuration ->
    . broker -> sqlakombu.transport.Transport://guest@sqlite:///MyDataBase.db/
    . queues ->
        . celery -> exchange:celery (direct) binding:celery
    . concurrency -> 4
    . loader -> celery.loaders.default.Loader
    . logfile -> [stderr]@INFO
    . events -> OFF
    . beat -> OFF
    . tasks ->
        . chatrooms.task.add
[2011-11-11 20:22:50,787: INFO/PoolWorker-1] child process calling self.run()
[2011-11-11 20:22:50,789: INFO/PoolWorker-2] child process calling self.run()
[2011-11-11 20:22:50,791: INFO/PoolWorker-3] child process calling self.run()
[2011-11-11 20:22:50,796: INFO/PoolWorker-4] child process calling self.run()
[2011-11-11 20:22:50,802: WARNING/MainProcess] [e-mail] has started.
[2011-11-11 20:22:50,804: WARNING/MainProcess] Traceback (most recent call last):
[2011-11-11 20:22:50,805: WARNING/MainProcess] File "/Users/shashkin/python_v_env/bin/celeryd",line 8,in kwargs).run()
[2011-11-11 20:22:50,806: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/celery-2.1.4-py2.7.egg/celery/apps/worker.py",line 121,807: WARNING/MainProcess] self.run_worker()
[2011-11-11 20:22:50,807: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/celery-2.1.4-py2.7.egg/celery/apps/worker.py",line 219,in run_worker
[2011-11-11 20:22:50,807: WARNING/MainProcess] worker.start()
[2011-11-11 20:22:50,807: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/celery-2.1.4-py2.7.egg/celery/worker/__init__.py",line 217,in start
[2011-11-11 20:22:50,808: WARNING/MainProcess] component.start()
[2011-11-11 20:22:50,808: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/celery-2.1.4-py2.7.egg/celery/worker/listener.py",line 238,808: WARNING/MainProcess] self.reset_connection()
[2011-11-11 20:22:50,line 416,in reset_connection
[2011-11-11 20:22:50,808: WARNING/MainProcess] self.connection = self._open_connection()
[2011-11-11 20:22:50,line 480,in _open_connection
[2011-11-11 20:22:50,809: WARNING/MainProcess] max_retries=conf.broKER_CONNECTION_MAX_RETRIES)
[2011-11-11 20:22:50,809: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/celery-2.1.4-py2.7.egg/celery/utils/__init__.py",line 276,in retry_over_time
[2011-11-11 20:22:50,809: WARNING/MainProcess] retval = fun(*args,**kwargs)
[2011-11-11 20:22:50,809: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/celery-2.1.4-py2.7.egg/celery/worker/listener.py",line 472,in _establish_connection
[2011-11-11 20:22:50,809: WARNING/MainProcess] conn.connect()                              # evaluate connection
[2011-11-11 20:22:50,809: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/carrot-0.10.7-py2.7.egg/carrot/connection.py",line 170,in connect
[2011-11-11 20:22:50,810: WARNING/MainProcess] return self.connection
[2011-11-11 20:22:50,810: WARNING/MainProcess] File "/Users/shashkin/python_v_env/lib/python2.7/site-packages/carrot-0.10.7-py2.7.egg/carrot/connection.py",line 135,in connection
[2011-11-11 20:22:50,810: WARNING/MainProcess] self._connection = self._establish_connection()
[2011-11-11 20:22:50,line 148,810: WARNING/MainProcess] return self.create_backend().establish_connection()
[2011-11-11 20:22:50,line 161,in create_backend
[2011-11-11 20:22:50,810: WARNING/MainProcess] return backend_cls(connection=self)
[2011-11-11 20:22:50,811: WARNING/MainProcess] TypeError
[2011-11-11 20:22:50,811: WARNING/MainProcess] :
[2011-11-11 20:22:50,811: WARNING/MainProcess] __init__() takes exactly 2 arguments (1 given)
[2011-11-11 20:22:50,811: INFO/MainProcess] process shutting down

我错过了什么？

2)后来我想在我的应用程序中启动Celery.芹菜 – 挂架包安装后我该怎么办？我应该在应用程序的.ini文件中放置芹菜的设置吗？有人可以给我任何一个例子,因为我在网上找到的那些对我没什么帮助.

谢谢.

最佳答案

这看起来像芹菜包及其依赖项之间的版本兼容性问题.使用最新版本的芹菜,2.4.5你的例子就可以了.使用2.1.4我得到了同样的错误.

如果由于任何原因您只需要2.1.4版本的芹菜,您必须找出降级所需的依赖项以使其正常工作.通过查看回溯,很可能,它将是胡萝卜依赖,但如果其他依赖需要特定版本的胡萝卜,你可能会陷入依赖地狱.

我强烈建议使用带有pip的virtualenv,以便能够轻松地试验包的版本.尝试使用Linux存储库中的Python包开发一些东西可能会非常痛苦.

buildout versions或pip requirements解决了这类问题,但AFAIK没有针对芹菜的固定依赖版本.