Problem description

Pymongo cannot connect to mongo cluster, even local is no problem.
Everything is fine with the command line.

The environmental background of the problem and what methods have you tried?

The local mongo has no authentication, and the cluster has permission to authenticate.

Everything is fine with the command line.

$ mongo localhost
 MongoDB shell version: 3.2.20
 > db.version()
 3.0.6
 > use hello
 switched to db hello
 > db
 hello
 > db.hello.count() # database and table name are all called hello
 7

Cluster

$ mongo -u user  -p password  remote_ip:remote_port/hello  --authenticationDatabase admin
 hello:PRIMARY> db.version()
 3.6.4-1.2

Pymongo version: 3.7.1. Try the following:

In [2]: from pymongo import MongoClient

In [3]: c2= MongoClient('mongodb://localhost/hello')

In [4]: db2=c2.get_database()

In [5]: db2['hello'].count()   # 本地mongo一切正常
Out[5]: 7

In [6]: c1=MongoClient("mongodb://user:password@remote_ip:remote_port/hello&authSource=admin")

In [7]: db1=c1.get_database()

In [8]: db1['hello'].count()
/home/work/venv36/bin/ipython:1: DeprecationWarning: count is deprecated. Use estimated_document_count or count_documents instead. Please note that $where must be replaced by $expr, $near must be replaced by $geoWithin with $center, and $nearSphere must be replaced by $geoWithin with $centerSphere
  #!/home/work/fsj/venv36/bin/python3.6
---------------------------------------------------------------------------
OperationFailure                          Traceback (most recent call last)
<ipython-input-8-bf661fbd7e9c> in <module>()
----> 1 db1['hello'].count()

~/fsj/venv36/lib/python3.6/site-packages/pymongo/collection.py in count(self, filter, session, **kwargs)
   1764         collation = validate_collation_or_none(kwargs.pop('collation', None))
   1765         cmd.update(kwargs)
-> 1766         return self._count(cmd, collation, session)
   1767
   1768     def create_indexes(self, indexes, session=None, **kwargs):

~/fsj/venv36/lib/python3.6/site-packages/pymongo/collection.py in _count(self, cmd, collation, session)
   1561     def _count(self, cmd, collation=None, session=None):
   1562         """Internal count helper."""
-> 1563         with self._socket_for_reads(session) as (sock_info, slave_ok):
   1564             res = self._command(
   1565                 sock_info,

/usr/local/lib/python3.6/contextlib.py in __enter__(self)
     79     def __enter__(self):
     80         try:
---> 81             return next(self.gen)
     82         except StopIteration:
     83             raise RuntimeError("generator didn't yield") from None

~/fsj/venv36/lib/python3.6/site-packages/pymongo/mongo_client.py in _socket_for_reads(self, read_preference)
   1099         server = topology.select_server(read_preference)
   1100
-> 1101         with self._get_socket(server) as sock_info:
   1102             slave_ok = (single and not sock_info.is_mongos) or (
   1103                 read_preference != ReadPreference.PRIMARY)

/usr/local/lib/python3.6/contextlib.py in __enter__(self)
     79     def __enter__(self):
     80         try:
---> 81             return next(self.gen)
     82         except StopIteration:
     83             raise RuntimeError("generator didn't yield") from None

~/fsj/venv36/lib/python3.6/site-packages/pymongo/mongo_client.py in _get_socket(self, server)
   1056     def _get_socket(self, server):
   1057         try:
-> 1058             with server.get_socket(self.__all_credentials) as sock_info:
   1059                 yield sock_info
   1060         except NetworkTimeout:

/usr/local/lib/python3.6/contextlib.py in __enter__(self)
     79     def __enter__(self):
     80         try:
---> 81             return next(self.gen)
     82         except StopIteration:
     83             raise RuntimeError("generator didn't yield") from None

~/fsj/venv36/lib/python3.6/site-packages/pymongo/pool.py in get_socket(self, all_credentials, checkout)
   1004         sock_info = self._get_socket_no_auth()
   1005         try:
-> 1006             sock_info.check_auth(all_credentials)
   1007             yield sock_info
   1008         except:

~/fsj/venv36/lib/python3.6/site-packages/pymongo/pool.py in check_auth(self, all_credentials)
    675
    676             for credentials in cached - authset:
--> 677                 auth.authenticate(credentials, self)
    678                 self.authset.add(credentials)
    679

~/fsj/venv36/lib/python3.6/site-packages/pymongo/auth.py in authenticate(credentials, sock_info)
    561     mechanism = credentials.mechanism
    562     auth_func = _AUTH_MAP.get(mechanism)
--> 563     auth_func(credentials, sock_info)
    564
    565

~/fsj/venv36/lib/python3.6/site-packages/pymongo/auth.py in _authenticate_default(credentials, sock_info)
    538             return _authenticate_scram(credentials, sock_info, 'SCRAM-SHA-1')
    539     elif sock_info.max_wire_version >= 3:
--> 540         return _authenticate_scram(credentials, sock_info, 'SCRAM-SHA-1')
    541     else:
    542         return _authenticate_mongo_cr(credentials, sock_info)

~/fsj/venv36/lib/python3.6/site-packages/pymongo/auth.py in _authenticate_scram(credentials, sock_info, mechanism)
    260                ('payload', Binary(b"n,," + first_bare)),
    261                ('autoAuthorize', 1)])
--> 262     res = sock_info.command(source, cmd)
    263
    264     server_first = res['payload']

~/fsj/venv36/lib/python3.6/site-packages/pymongo/pool.py in command(self, dbname, spec, slave_ok, read_preference, codec_options, check, allowable_errors, check_keys, read_concern, write_concern, parse_write_concern_error, collation, session, client, retryable_write, publish_events)
    577                            compression_ctx=self.compression_context,
    578                            use_op_msg=self.op_msg_enabled,
--> 579                            unacknowledged=unacknowledged)
    580         except OperationFailure:
    581             raise

~/fsj/venv36/lib/python3.6/site-packages/pymongo/network.py in command(sock, dbname, spec, slave_ok, is_mongos, read_preference, codec_options, session, client, check, allowable_errors, address, check_keys, listeners, max_bson_size, read_concern, parse_write_concern_error, collation, compression_ctx, use_op_msg, unacknowledged)
    148                 helpers._check_command_response(
    149                     response_doc, None, allowable_errors,
--> 150                     parse_write_concern_error=parse_write_concern_error)
    151     except Exception as exc:
    152         if publish:

~/fsj/venv36/lib/python3.6/site-packages/pymongo/helpers.py in _check_command_response(response, msg, allowable_errors, parse_write_concern_error)
    153
    154             msg = msg or "%s"
--> 155             raise OperationFailure(msg % errmsg, code, response)
    156
    157

OperationFailure: Authentication failed.

According to the documenthttps://api.mongodb.com/pytho …No problem with the inspection.

Local is 3.0, cluster is 3.6, authentication mechanism should be the default SCRAM-SHA-1

How to deal with it, please