multi-master setting/configuration

I feel like I’m missing something basic.  Is “multi-master” a built-in feature or it must be configured/enabled?  I can’t seem to find a “turn it on setting”.The odd time my application ends up in a split-brain scenario, it seems to struggle greatly, which leads me to believe transactions aren’t getting committed across the cluster.  Mind you, I ended up supported a geographically separated cluster, and it seems that’s a no-no for multi-master (https://www.percona.com/blog/2018/11/15/how-not-to-do-mysql-high-availability-geographic-node-distribution-with-galera-based-replication-misuse/).

Hi, i’m assuming that you are running the Percona XtraDB Cluster. When properly deployed, you can use PXC with “Multi-Master” from scratch, you don’t need to enable anything. However, PXC is not a multi master solution, is a High Availability (HA) solution that allows you to write to different nodes.