connecting user based mongodb instance

[thatsk]

Traceback (most recent call last):
File "/bin/motop", line 4, in
motop.run()
File "/usr/lib/python2.7/site-packages/libmotop/motop.py", line 78, in run
servers = commonServers(config, arguments)
File "/usr/lib/python2.7/site-packages/libmotop/motop.py", line 67, in commonServers
return [Server(section, **dict(config.items(section))) for section in config.sections()]
File "/usr/lib/python2.7/site-packages/libmotop/server.py", line 30, in init
self.tryToConnect()
File "/usr/lib/python2.7/site-packages/libmotop/server.py", line 43, in tryToConnect
self.__connection.admin.authenticate(self.__username, self.__password)
File "/usr/lib64/python2.7/site-packages/pymongo/database.py", line 1048, in authenticate
connect=True)
File "/usr/lib64/python2.7/site-packages/pymongo/mongo_client.py", line 505, in _cache_credentials
sock_info.authenticate(credentials)
File "/usr/lib64/python2.7/site-packages/pymongo/pool.py", line 523, in authenticate
auth.authenticate(credentials, self)
File "/usr/lib64/python2.7/site-packages/pymongo/auth.py", line 470, in authenticate
auth_func(credentials, sock_info)
File "/usr/lib64/python2.7/site-packages/pymongo/auth.py", line 450, in _authenticate_default
return _authenticate_scram_sha1(credentials, sock_info)
File "/usr/lib64/python2.7/site-packages/pymongo/auth.py", line 201, in _authenticate_scram_sha1
res = sock_info.command(source, cmd)
File "/usr/lib64/python2.7/site-packages/pymongo/pool.py", line 419, in command
collation=collation)
File "/usr/lib64/python2.7/site-packages/pymongo/network.py", line 116, in command
parse_write_concern_error=parse_write_concern_error)
File "/usr/lib64/python2.7/site-packages/pymongo/helpers.py", line 210, in _check_command_response
raise OperationFailure(msg % errmsg, code, response)
pymongo.errors.OperationFailure: Authentication failed.

[thatsk]

i have installed on centos instance and it has user based authentication to mongodb database but when i run motop it gives above error