redis-py - MISCONF Redis is configured to save RDB snapshots, ...

어느 순간, 테스트 서버에서 호스팅 중인 컨테이너에서 각종 오류들이 쏟아졌습니다. ^^; 가령, redis 호출에 대해서는 이런 오류 메시지가 나오고,

Traceback (most recent call last):
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 2190, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1486, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1484, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  ...[생략]...
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1469, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/mnt/d/workshop2/python-agent/testprj/latest_flask/pybo/views/main_views.py", line 190, in redis_test
    client.set('my_db', 5)
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/commands/core.py", line 1453, in set
    return self.execute_command('SET', *pieces, **options)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ...[생략]...
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/client.py", line 1071, in execute_command
    return conn.retry.call_with_retry(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/retry.py", line 32, in call_with_retry
    return do()
           ^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/client.py", line 1072, in <lambda>
    lambda: self._send_command_parse_response(conn,
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/client.py", line 1051, in _send_command_parse_response
    return self.parse_response(conn, command_name, **options)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/client.py", line 1084, in parse_response
    response = connection.read_response()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/redis/connection.py", line 765, in read_response
    raise response
redis.exceptions.ResponseError: MISCONF Redis is configured to save RDB snapshots, but it is currently not able to persist on disk. Commands that may modify the data set are disabled, because this instance is configured to report errors during writes if RDB snapshotting fails (stop-writes-on-bgsave-error option). Please check the Redis logs for details about the RDB error.

Traceback (most recent call last):
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 2190, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1486, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1484, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  ...[생략]...
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1469, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/mnt/d/workshop2/python-agent/testprj/latest_flask/pybo/views/main_views.py", line 215, in pymongotest
    db2.users.delete_many({'y': 1})
  ...[생략]...
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/collection.py", line 1451, in delete_many
    self._delete_retryable(
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/collection.py", line 1360, in _delete_retryable
    return self.__database.client._retryable_write(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/mongo_client.py", line 1643, in _retryable_write
    with self._tmp_session(session) as s:
  File "/usr/lib/python3.11/contextlib.py", line 137, in __enter__
    return next(self.gen)
           ^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/mongo_client.py", line 2040, in _tmp_session
    s = self._ensure_session(session)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/mongo_client.py", line 2027, in _ensure_session
    return self.__start_session(True, causal_consistency=False)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/mongo_client.py", line 1976, in __start_session
    server_session = self._get_server_session()
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/mongo_client.py", line 2013, in _get_server_session
    return self._topology.get_server_session()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/topology.py", line 525, in get_server_session
    session_timeout = self._check_session_support()
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/topology.py", line 507, in _check_session_support
    self._select_servers_loop(
  File "/home/testusr/.local/lib/python3.11/site-packages/pymongo/topology.py", line 226, in _select_servers_loop
    raise ServerSelectionTimeoutError(
pymongo.errors.ServerSelectionTimeoutError: 192.168.100.50:15000: [Errno 111] Connection refused, Timeout: 30s, Topology Description: <TopologyDescription id: 6508f21066abc5620a3c1622, topology_type: Single, servers: [<ServerDescription ('192.168.100.50', 15000) server_type: Unknown, rtt: None, error=AutoReconnect('192.168.100.50:15000: [Errno 111] Connection refused')>]>

Traceback (most recent call last):
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 2190, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1487, in full_dispatch_request
    return self.finalize_request(rv)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1506, in finalize_request
    response = self.make_response(rv)
               ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/testusr/.local/lib/python3.11/site-packages/flask/app.py", line 1801, in make_response
    raise TypeError(
TypeError: The view function for 'main.mysqlclient_wrapper2' did not return a valid response. The function either returned None or ended without a return statement.