I know that changing wsrep_gtid_domain_id in the configuration file on all nodes requires a full cluster stop and restart to pick up the change as only the first node will actually use the config file value, while all further nodes receive the value to use from their donor during IST/SST.

But when e.g. changing the relevant configuration settings from

wsrep-gtid-mode=ON

wsrep_gtid_domain_id=100

gtid_domain_id=...different value per node....

to

wsrep_gtid_domain_id=200

then stopping all nodes, staring node-1 with galera_new_cluster, and node-2 with systemctl start mariadb, all is fine so far, both nodes show wsrep_gtid_domain_id=200 in SHOW VARIABLES LIKE 'wsrep_gtid_domain_id'. But when starting a 3rd or further nodes they all usually still show 100 instead of 200.

Looking at the error logs I see node-3 usually use node-2 as donor, not node-1.

When I force the node started with galera_new_cluster as the default donor with wsrep_sst_donor=node-1 I get the correct new 200 value on all nodes though.

So somehow nodes seem to remember the previous value and pass that on to joiners instead of the value they received from their own donor, or read from their configuration file.