我在aws上启动了一个ec2示例，现在正在使用ubuntu。我能够在示例本身上连接到mysql(i、 e.mysql-h localhost-u root-p）
但是当我尝试从远程计算机连接时（例如mysql-h ipaddress-u remoteun-p）

ERROR 2003 (HY000): Can't connect to MySQL server on 'ipaddress' (61)

我已经更改了安全设置，允许所有ip地址连接到端口3306和端口22，并在示例上创建了一个可以从远程服务器访问mysql的用户

> CREATE USER 'tempuser'@'%' IDENTIFIED BY 'password';
> GRANT ALL PRIVILEGES ON *.* TO 'tempuser'@'%'
> WITH GRANT OPTION;

我尝试使用

> service mysqld restart

得到以下信息

==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to restart 'mysqld.service'.

身份验证为：ubuntu（ubuntu）密码：
我不确定默认密码是什么，当我输入mysql密码时

polkit-agent-helper-1: pam_authenticate failed: Authentication failure
==== AUTHENTICATION FAILED ===
Failed to restart mysqld.service: Access denied
See system logs and 'systemctl status mysqld.service' for details.

> systemctl status mysqld.service
  mysqld.service
  Loaded: not-found (Reason: No such file or directory)
  Active: inactive (dead)

有人知道什么是默认密码，或者如何重新启动服务器以便我可以远程连接吗？