Galera mysqld_multi - possible bug
Not sure where to post this but I've come across this on a SLES 12 system. Running Galera 25.3.9-1 / MariaDB 10.1.6-1.
Using the Mysqld_multi init.d script to start and stop multiple mysql instances through service or systemd commands I have found that the starting works just fine but stopping them doesn't. It will stop all the instances but the last one. Just for clarification cmd is : service mysqld_multi stop or systemctl stop mysqld_multi.
I tried this with 2 and 3 mysql instances. With 2 instances, #1 would stop but #2 wouldn't. With 3 instances #1 & #2 would stop and #3 wouldn't. I have verified that the mysqladmin command works to shut the DB down with the multi_admin account I use.
Now running mysqld_multi directly works just fine. Whether it's one specific instance or all of them. That is running the script directly /etc/init.d/mysqd_multi or the actual /usr/bin/mysqld_multi command directly. Both work as expected. I honestly don't know if this is a script problem or a systemd problem. I do know that in SLES 12, SUSE rewrote the mysql init.d script to include mysqld_multi if multiple instances were discovered in the my.cnf file. And this work great using systemd.
Anyway there it is, if anyone has come across this on other systems it might be worth noting.
Answer Answered by Ian Gilfillan in this comment.
I suggest reporting this as a bug on JIRA.