Keystone prompt error when synchronizing database

The Keystone reported the following error when synchronizing:

"Keystone-manage Db_sync" Keystone

CRITICAL Keystone [-] Dberror: (pymysql.err.InternalError) (1071, U ' Specified key was too long; Max key length is 767 byte S ') [sql:u ' \ncreate TABLE migrate_version (\n\trepository_id VARCHAR () not NULL, \n\trepository_path TEXT, \n\tversio n INTEGER, \n\tprimary KEY (repository_id) \ n \ n "]

Solution:

Modify:
#cd/ETC/MYSQL/MARIADB.CONF.D
Modify the character set in each of the following files to Utf8mb4, UTF8, and then restart MySQL to log in to the MySQL query database default character set:
MariaDB [(None)]> show variables like "%char%";
+--------------------------+----------------------------+
| variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | UTF8 |
| character_set_connection | UTF8 |
| Character_set_database | UTF8 |
| Character_set_filesystem | binary |
| Character_set_results | UTF8 |
| Character_set_server | UTF8 |
| Character_set_system | UTF8 |
| Character_sets_dir | /usr/share/mysql/charsets/|
+--------------------------+----------------------------+

Delete the Keystone database and recreate it.

Keystone prompt error when synchronizing database