MySQL 服务器运行良好，但突然断线了，我无法从 WorkBench 连接到它。
#sudo service mysql status
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: active (running) since Wed 2023-04-19 08:18:38 EEST; 57min ago
Process: 760 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
Main PID: 940 (mysqld)
Status: "Server is operational"
Tasks: 39 (limit: 9433)
Memory: 436.7M
CPU: 9.452s
CGroup: /system.slice/mysql.service
└─940 /usr/sbin/mysqld
守护进程正在运行
#ps xa | grep mysqld
940 ? Ssl 0:11 /usr/sbin/mysqld
13439 pts/1 S+ 0:00 grep --color=auto mysqld
港口开通
#sudo ss -tap | grep mysql
LISTEN 0 151 192.168.0.3:mysql 0.0.0.0:* users:(("mysqld",pid=940,fd=33))
LISTEN 0 70 192.168.0.3:33060 0.0.0.0:* users:(("mysqld",pid=940,fd=31))
日志中没有特殊警告，只有普通消息
#sudo journalctl -u mysql
[MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.32-0ubuntu0.22.04.2>
[MY-013576] [InnoDB] InnoDB initialization has started.
[MY-013577] [InnoDB] InnoDB initialization has ended.
[MY-010068] [Server] CA certificate ca.pem is self signed.
[MY-013602] [Server] Channel mysql_main configured to support TLS. En>
[MY-011323] [Server] X Plugin ready for connections. Bind-address: ':>
[MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version>
MySQL 版本
#mysqladmin version
mysqladmin Ver 8.0.32-0ubuntu0.22.04.2 for Linux on x86_64 ((Ubuntu))
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners.
Server version 8.0.32-0ubuntu0.22.04.2
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/run/mysqld/mysqld.sock
Uptime: 1 hour 8 min 42 sec
Threads: 2 Questions: 8 Slow queries: 0 Opens: 136 Flush tables: 3 Open tables: 55 Queries per second avg: 0.001
但连接是不可能的
#mysqladmin -h `hostname` --port=3306 version
mysqladmin: connect to server at 'php-desktop' failed
error: 'Can't connect to MySQL server on 'php-desktop:3306' (111)'
Check that mysqld is running on php-desktop and that the port is 3306.
You can check this by doing 'telnet php-desktop 3306'
发生了什么事以及如何修复与服务器的连接？