Zabbix 4.0 change DBhost doesn't useful.

[surex_zabbix]

OS: Linux Centos 7.2.
Zabbix: 4.0

After install Zabbix 4.0 I have changed the DBhost to a cloud database link, such as rdsXXXXXXXXXXXX.mysql.rds.aliyuncs.com.
When I start zabbix-server the port 10051 did not set up. And log says that Zabbix try to connect to mysql with Linux intranet IP.

" 26185:20190730:152512.869 [Z3001] connection to database 'zabbix-database' failed: [1045] Access denied for user 'zabbix-database'@'192.168.2.253' (using password: YES)
26185:20190730:152512.869 database is down: reconnecting in 10 seconds
26185:20190730:152522.871 [Z3001] connection to database 'zabbix-database' failed: [1045] Access denied for user 'zabbix-database'@'192.168.2.253' (using password: YES)
26185:20190730:152522.871 database is down: reconnecting in 10 seconds "

But when I change DBhost to a number IP, such as 177.46.126.57 and restart zabbix-server. The log will connect to this IP.

Does the DBhost can't use link like rdsXXXXXXXXXXXX.mysql.rds.aliyuncs.com?

When I set up the php website, I can use the link to pass the install of Zabbix. I don't know why it can't use in zabbix-server.

Hope anyone can help me.

Thanks.

Richad.