[#MDEV-24431] galera.unique_key MTR failed: WSREP: Refusing exit for the last slave thread

galera.unique_key MTR failed on BB, 10.2 CS: "WSREP: Refusing exit for the last slave thread".
It seems to be a sporadic issue.

10.2.37, 74223c33d1aeffac28b155c59646dc3df58e33fb, kvm-rpm-centos74-amd64-debug
galera.unique_key 'innodb' w1 [ fail ] Found warnings/errors in server log file!
Test ended at 2020-12-15 10:31:05
line
2020-12-15 10:31:05 140114214921984 [Warning] WSREP: Refusing exit for the last slave thread.
^ Found warnings in /dev/shm/var/1/log/mysqld.2.err
ok

- saving '/dev/shm/var/1/log/galera.unique_key-innodb/' to '/dev/shm/var/log/galera.unique_key-innodb/'

Retrying test galera.unique_key, attempt(2/3)...

worker[1] > Restart - not started
worker[1] > Restart - not started

[MDEV-24431] galera.unique_key MTR failed: WSREP: Refusing exit for the last slave thread Created: 2020-12-17 Updated: 2023-06-06 Resolved: 2023-06-06
Status:	Closed
Project:	MariaDB Server
Component/s:	Galera, Tests
Affects Version/s:	10.2.37
Fix Version/s:	N/A