In [36]: c = pymongo.MongoClient('cn14:27119')

In [38]: len(c.mongoose.collection_names())
Out[38]: 608

In [39]: len(c.mongoose.collection_names())
Out[39]: 608

In [40]: len(c.mongoose.collection_names())
Out[40]: 608

In [41]: len(c.mongoose.collection_names())
Out[41]: 608

In [42]: len(c.mongoose.collection_names())
Out[42]: 608

In [43]: len(c.mongoose.collection_names())
Out[43]: 608

In [44]: len(c.mongoose.collection_names())
Out[44]: 608

In [45]: len(c.mongoose.collection_names())
Out[45]: 608

In [46]: len(c.mongoose.collection_names())
Out[46]: 608

In [47]: len(c.mongoose.collection_names())
Out[47]: 608

In [48]: len(c.mongoose.collection_names())
Out[48]: 608

In [49]: len(c.mongoose.collection_names())
Out[49]: 608

In [50]: len(c.mongoose.collection_names())
Out[50]: 608

In [51]: len(c.mongoose.collection_names())
Out[51]: 608

In [52]: len(c.mongoose.collection_names())
Out[52]: 608

In [53]: len(c.mongoose.collection_names())
Out[53]: 608

In [54]: len(c.mongoose.collection_names())
Out[54]: 608

In [55]: len(c.mongoose.collection_names())
Out[55]: 608

In [56]: len(c.mongoose.collection_names())
Out[56]: 608

In [57]: len(c.mongoose.collection_names())
Out[57]: 608

In [58]: len(c.mongoose.collection_names())
Out[58]: 608







In [59]: c = pymongo.MongoClient('cn14:27119,cn15:27119')

In [61]: len(c.mongoose.collection_names())
Out[61]: 608

In [62]: len(c.mongoose.collection_names())
Out[62]: 608

In [63]: len(c.mongoose.collection_names())
Out[63]: 608

In [64]: len(c.mongoose.collection_names())
Out[64]: 608

In [65]: len(c.mongoose.collection_names())
Out[65]: 608

In [66]: len(c.mongoose.collection_names())
Out[66]: 608

In [67]: len(c.mongoose.collection_names())
Out[67]: 608

In [68]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-68-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839931427696141672 over collection mongoose.system.namespaces

In [69]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-69-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839930483967548518 over collection mongoose.system.namespaces

In [70]: len(c.mongoose.collection_names())
Out[70]: 608

In [71]: len(c.mongoose.collection_names())
Out[71]: 608

In [72]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-72-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839926060692373674 over collection mongoose.system.namespaces

In [73]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-73-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839925071557381879 over collection mongoose.system.namespaces

In [74]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-74-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839924041130424006 over collection mongoose.system.namespaces

In [75]: len(c.mongoose.collection_names())
Out[75]: 608

In [76]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-76-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839921935994724217 over collection mongoose.system.namespaces

In [77]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-77-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839920905136194059 over collection mongoose.system.namespaces

In [78]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-78-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839919832982252535 over collection mongoose.system.namespaces

In [79]: len(c.mongoose.collection_names())
Out[79]: 608

In [80]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-80-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839917728262627128 over collection mongoose.system.namespaces

In [81]: len(c.mongoose.collection_names())
Out[81]: 608

In [82]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-82-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839915623765092903 over collection mongoose.system.namespaces

In [83]: len(c.mongoose.collection_names())
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-83-7faedde15403> in <module>()
----> 1 len(c.mongoose.collection_names())

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/database.py in collection_names(self, include_system_collections)
    489 
    490             results = self._list_collections(sock_info, slave_okay)
--> 491             names = [result["name"] for result in results]
    492             if sock_info.max_wire_version <= 2:
    493                 # MongoDB 2.4 and older return index namespaces and collection

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in next(self)
    166         """Advance the cursor.
    167         """
--> 168         if len(self.__data) or self._refresh():
    169             coll = self.__collection
    170             return coll.database._fix_outgoing(self.__data.popleft(), coll)

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in _refresh(self)
    135         if self.__id:  # Get More
    136             self.__send_message(
--> 137                 _GetMore(self.__ns, self.__batch_size, self.__id))
    138 
    139         else:  # Cursor id is zero nothing else to return

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/command_cursor.py in __send_message(self, operation)
    104             doc = helpers._unpack_response(response.data,
    105                                            self.__id,
--> 106                                            self.__collection.codec_options)
    107         except CursorNotFound:
    108             self.__killed = True

/local/home/jblackburn/pyenvs/research/lib/python2.7/site-packages/pymongo-3.0.1_1_d3aa09-py2.7-linux-x86_64.egg/pymongo/helpers.py in _unpack_response(response, cursor_id, codec_options)
    120                                error_object.get("$err"),
    121                                error_object.get("code"),
--> 122                                error_object)
    123 
    124     result = {}

OperationFailure: database error: could not find cursor in cache for id 7839914591397814190 over collection mongoose.system.namespaces

In [84]: len(c.mongoose.collection_names())
Out[84]: 608

In [85]: len(c.mongoose.collection_names())
Out[85]: 608

In [86]: len(c.mongoose.collection_names())
Out[86]: 608

In [87]: len(c.mongoose.collection_names())
Out[87]: 608

In [88]: len(c.mongoose.collection_names())
Out[88]: 608

In [89]: len(c.mongoose.collection_names())
Out[89]: 608