After hours of searching I find lots of tutorials that do only 2 server Master Master. Now I wonder how to setup multi master setup because this is more suitable in my business. Because when the WAN connection is down my transaction in area's are still on going and then when the connection is back the changes in servers will be sync on. That's why i need multi master setup. Thanks in advance for any help and tips
MySQL Server master-master replication is possible for max 2 nodes.
You might want to use Galera Cluster (Percona Xtradb Cluster or Mariadb Galera cluster) Or Oracle's NDB Cluster to achieve HA as a better solution than master-master.