When creating an index on mongo, pymongo raised following exception:
Exception in thread 858: Traceback (most recent call last): File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner self.run() File "/usr/lib/python2.7/threading.py", line 763, in run self.__target(*self.__args, **self.__kwargs) File "parallel_index_creation.py", line 17, in thread_run col.ensure_index('field1', cache_for=-1) File ".../pymongo/collection.py", line 1406, in ensure_index self.__name, name): File ".../pymongo/mongo_client.py", line 439, in _cached now < cache[dbname][coll][index]) KeyError: u'field1_1'
I have attached small script that reproduces it (after few runs).