How can I specify which MariaDB instance to launch in a Galera Cluster

Question

I have several MariaDB servers, each with multiple instances running. I'm trying to figure out how would I bootstrap a Galera cluster but specify which instance I want to launch i.e:

node1, 2, and 3 each has instances 1-4 running via mysqld_multi, each running on their own port.

I want to use instance 4 on each server for the cluster, so I shut each one down.

On my test cluster (which has a single instance of MariaDB running) bootstrapping is simple: start it on the first node with galera_new_cluster then bring up the other two servers.

How would I do the same thing but specify GNR "4" to bootstrap the cluster?

Answer 1

According to the output from mysqld_multi --help:

--wsrep-new-cluster  Bootstrap a cluster.

So on the node you want to bootstrap, I'm assuming you should be able to do:

mysqld_multi --wsrep-new-cluster start 4

And then start the instances on the other two the normal way, assuming all the instances have the necessary config files.