May I ask you if you’ve followed this article - https://www.digitalocean.com/community/tutorials/how-to-create-a-multi-node-mysql-cluster-on-ubuntu-18-04
If that is correct you can tweak/edit the /var/lib/mysql-cluster/config.ini file according to your needs.
To change the hostname of the droplet you can use the following command (for Ubuntu droplet)
In Ubuntu 18.04 we can change the system hostname and related settings using the command hostnamectl.
For example, to change the system static hostname to production, you would use the following command:
sudo hostnamectl set-hostname production
Then open the /etc/hosts file and change the old hostname to the new one.
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
To verify that the hostname was successfully changed, once again use the hostnamectl command:
Let me know how it goes.
The MySQL Cluster distributed database provides high availability and throughput for your MySQL database management system. This tutorial demonstrates how to install and configure a 3 node MySQL Cluster on Ubuntu 18.04 servers.