服務器配置了防火牆，開放部分端口

root@Mrtan bin]# firewall-cmd --zone=public --add-port=18083/tcp --permanent
success
[root@Mrtan bin]# systemctl restart firewalld
[root@Mrtan bin]# firewall-cmd --zone=public --add-port=3306/tcp --permanent
success
[root@Mrtan bin]# systemctl restart firewalld
[root@Mrtan bin]# firewall-cmd --zone=public --add-port=1883/tcp --permanent
success
[root@Mrtan bin]# systemctl restart firewalld