pymongo多线程报错Address already in use

我用cygwin跑的Python，开了1000个线程读取mongodb的数据，前面好好的，后面就开始报错了，这个问题挺久了，试了网上的方法好像都无效

  File "/usr/lib/python2.7/site-packages/pymongo/collection.py", line 2524, in remove
    with self._socket_for_writes() as sock_info:
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/usr/lib/python2.7/site-packages/pymongo/mongo_client.py", line 825, in _get_socket
    with server.get_socket(self.__all_credentials) as sock_info:
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/usr/lib/python2.7/site-packages/pymongo/server.py", line 168, in get_socket
    with self.pool.get_socket(all_credentials, checkout) as sock_info:
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/usr/lib/python2.7/site-packages/pymongo/pool.py", line 790, in get_socket
    sock_info = self._get_socket_no_auth()
  File "/usr/lib/python2.7/site-packages/pymongo/pool.py", line 826, in _get_socket_no_auth
    sock_info, from_pool = self.connect(), False
  File "/usr/lib/python2.7/site-packages/pymongo/pool.py", line 763, in connect
    _raise_connection_failure(self.address, error)
  File "/usr/lib/python2.7/site-packages/pymongo/pool.py", line 211, in _raise_connection_failure
    raise AutoReconnect(msg)
AutoReconnect: 127.0.0.1:27017: [Errno 112] Address already in use