Question :
I did an ALTER TABLE on a huge table on a MariaDB Galera Cluster 10.2, but after a while of waiting I changed my mind and tried to kill the connection. However, MariaDB said ERROR 1095 (HY000): You are not owner of thread 123 even though I most definitely am the owner. So what is going on?
Answer :
The error message is misleading. Galera can mark user threads as high priority which means they can’t be killed. Currently, this gives the ERROR 1095 (HY000): You are not owner of thread… See MDEV-12008 for details.
This will probably affect other distributions of Galera as well, such as Percona XtraDB Cluster.