OperationFailure:在MongoEngine/PyMongo中执行线程时发生数据库错误

Question

我有一个函数，它将从网站读取数据，进行处理，然后将其加载到MongoDB中。当我在没有线程的情况下运行它时，它工作得很好，但一旦我设置了只调用这一个函数的芹菜任务，我就会经常收到以下错误："OperationFailure:database error:unauthorized db:dbname lock type:-1"

这有点奇怪，因为如果我在多个终端上运行非芹菜版本，我根本不会得到这个错误。

我怀疑这与没有打开到Mongo的连接有关，尽管在我的代码中，我在每次Mongo调用之前都会打开一个连接。

确切的例外情况如下：

Task twitter[a974bfcc-d6ca-4baf-b36f-cae9143ce2d9] raised exception: OperationFailure(u'database error: unauthorized db:data lock type:-1 client:68.193.49.9',)
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/celery/execute/trace.py", line 36, in trace
  return cls(states.SUCCESS, retval=fun(*args, **kwargs))
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/celery/app/task/__init__.py", line 232, in __call__
  return self.run(*args, **kwargs)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/celery/app/__init__.py", line 172, in run
  return fun(*args, **kwargs)
File "/djangoblog/network/tasks.py", line 40, in twitter
  n_twitter.GetTweetsTwitter(user)
File "/djangoblog/network/twitter.py", line 255, in GetTweetsTwitter
  id = SaveTweet(user, network, tweet)
File "/djangoblog/network/twitter.py", line 150, in SaveTweet
  if mmo.Moment.objects(user=user.id,source_id=id,network=network.id).count() == 0:
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/mongoengine/queryset.py", line 933, in count
  return self._cursor.count(with_limit_and_skip=True)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/mongoengine/queryset.py", line 563, in _cursor
  self._cursor_obj = self._collection.find(self._query,
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/mongoengine/queryset.py", line 493, in _collection
  if self._collection_obj.name not in db.collection_names():
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/pymongo/database.py", line 361, in collection_names
  names = [r["name"] for r in results]
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/pymongo/cursor.py", line 703, in next
  if len(self.__data) or self._refresh():
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/pymongo/cursor.py", line 666, in _refresh
  self.__uuid_subtype))
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/pymongo/cursor.py", line 628, in __send_message self.__tz_aware)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/pymongo/helpers.py", line 101, in _unpack_response error_object["$err"])
OperationFailure: database error: unauthorized db:data lock type:-1 client:68.193.49.9

很抱歉格式化，但如果你看看以mmo开头的行。在调用之前，有一个连接正在打开。

做一点研究，它看起来似乎与PyMongo中处理线程的方式有关——http://api.mongodb.org/python/1.5.1/faq.html#how-连接池在pymongo中工作吗？我可能需要开始关闭连接，但我希望MongoEngine会这样做。。

Answer 1

这可能是因为当您启动新连接并在MongoDB上使用auth时，您没有调用db.authenticate（）。

关于线程的关闭，我建议您确保使用连接池，并让驱动程序管理池（手动调用close（）或类似操作可能会带来很多痛苦）。

有关更多信息，请参阅pymongo文档中关于在多线程环境中使用authenticate（）的说明。