B4J Question This site can’t be reached message jRDC2 on VPS

Hi,

When I test my test.jar(jRDC application server) on my pc, everything is ok.

Now I run test.jar on vps.
Application is run.
When I access with my pc browser, it shows This site can’t be reached in browser.
So I test
curl http://127.0.0.1:17178/test
on vps console.
It shows
RemoteServer is running (01/09/2019 15:04:35)<br/>Error fetching connection.root@mysql-s-1vcpu-2gb-s

I already opened the firewall port 17178
sudo iptables -I INPUT -p tcp -m tcp --dport 17178 -j ACCEPT

How can I fix it?