SET @@global.keyring_file= 'new_keyring_file';
ERROR HY000: Unknown system variable 'keyring_file'
INSTALL PLUGIN keyring SONAME 'keyring.so';
SET @@global.keyring_file= 'new_keyring_file';
SET @@global.keyring_file= 'mysecret_keyring';
UNINSTALL PLUGIN keyring;