我目前正在尝试使用MongoDB Atlas（因此我认为这是一个云服务器，对于该错误起很大的作用），mongoengine和pymongo（所有最新版本为）在flask Web应用程序中实现用户创建和登录系统的帖子）。每当我在创建用户表单上提交用户名和密码并尝试通过查询数据库来验证用户名不存在时，都会收到以下错误消息：

pymongo.errors.ServerSelectionTimeoutError: localhost:27017: [WinError 10061] No connection could be made because the target machine actively refused it

这是完整的追溯：

    File "C:\Programming\Python\Lib\site-packages\flask\app.py",line 2463,in __call__
    return self.wsgi_app(environ,start_response)
  File "C:\Programming\Python\Lib\site-packages\flask\app.py",line 2449,in wsgi_app
    response = self.handle_exception(e)
  ...
    rv = self.dispatch_request()
  File "C:\Programming\Python\Lib\site-packages\flask\app.py",line 1935,in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Programming\Khimbus\src\client\views\user_views.py",line 27,in create_user
    account_exists = find_user_by_username(username)
  File "C:\Programming\Khimbus\src\services\user_service.py",line 20,in find_all_users
    users = User.objects()
  File "C:\Programming\Python\Lib\site-packages\mongoengine\queryset\manager.py",line 37,in __get__
    queryset = queryset_class(owner,owner._get_collection())
  File "C:\Programming\Python\Lib\site-packages\mongoengine\document.py",line 207,in _get_collection
    db.client.is_primary:
  File "C:\Programming\Python\Lib\site-packages\pymongo\mongo_client.py",line 1006,in is_primary
    return self._server_property('is_writable')
  File "C:\Programming\Python\Lib\site-packages\pymongo\mongo_client.py",line 830,in _server_property
    server = self._topology.select_server(
  File "C:\Programming\Python\Lib\site-packages\pymongo\topology.py",line 229,in select_server
    return random.choice(self.select_servers(selector,File "C:\Programming\Python\Lib\site-packages\pymongo\topology.py",line 188,in select_servers
    server_descriptions = self._select_servers_loop(
  File "C:\Programming\Python\Lib\site-packages\pymongo\topology.py",line 204,in _select_servers_loop

REST端点：

    @user_views.route('/create-user',methods=['GET','POST'])
    def create_user():
    if request.method == 'POST':
        print('Creating user...')
        username = request.form['username']
        password = request.form['password']

        account_exists = find_user_by_username(username)
        if account_exists:
            print(f'Error: account with {username} already exists.')
            return render_template('error_page.html')

        hashpass = generate_password_hash(password)
        user_state.active_account = create_user(username,hashpass)
        print(user_state.active_account.username)
        session['username'] = user_state.active_account.username
        resp = jsonify('Created new account!')
        resp.status_code = 200
        return resp

    return render_template('create_user.html')

查找用户方法：

def find_user_by_username(username: str) -> User:
    print('Finding user...')
    user = User.objects(username=username)
    print('Found user' + user)
    return user

我不确定这里发生了什么，其他相关问题涵盖了不同的错误代码，或者由于过时而无法帮助我使用MongoDB Atlas。我将不胜感激！

更新：已解决

安装MongoDB时，没有将其安装为Windows服务。我已经重新安装了它，现在用户创建工作正常。