Run mysql_upgrade once
mysql.columns_priv                                 OK
mysql.db                                           OK
mysql.func                                         OK
mysql.help_category                                OK
mysql.help_keyword                                 OK
mysql.help_relation                                OK
mysql.help_topic                                   OK
mysql.host                                         OK
mysql.proc                                         OK
mysql.procs_priv                                   OK
mysql.tables_priv                                  OK
mysql.time_zone                                    OK
mysql.time_zone_leap_second                        OK
mysql.time_zone_name                               OK
mysql.time_zone_transition                         OK
mysql.time_zone_transition_type                    OK
mysql.user                                         OK
Run it again - should say already completed
This installation of MySQL is already upgraded to VERSION, use --force if you still need to run mysql_upgrade
Force should run it regardless of wether it's been run before
mysql.columns_priv                                 OK
mysql.db                                           OK
mysql.func                                         OK
mysql.help_category                                OK
mysql.help_keyword                                 OK
mysql.help_relation                                OK
mysql.help_topic                                   OK
mysql.host                                         OK
mysql.proc                                         OK
mysql.procs_priv                                   OK
mysql.tables_priv                                  OK
mysql.time_zone                                    OK
mysql.time_zone_leap_second                        OK
mysql.time_zone_name                               OK
mysql.time_zone_transition                         OK
mysql.time_zone_transition_type                    OK
mysql.user                                         OK
CREATE USER mysqltest1@'%' IDENTIFIED by 'sakila';
GRANT ALL ON *.* TO mysqltest1@'%';
Run mysql_upgrade with password protected account
mysql.columns_priv                                 OK
mysql.db                                           OK
mysql.func                                         OK
mysql.help_category                                OK
mysql.help_keyword                                 OK
mysql.help_relation                                OK
mysql.help_topic                                   OK
mysql.host                                         OK
mysql.proc                                         OK
mysql.procs_priv                                   OK
mysql.tables_priv                                  OK
mysql.time_zone                                    OK
mysql.time_zone_leap_second                        OK
mysql.time_zone_name                               OK
mysql.time_zone_transition                         OK
mysql.time_zone_transition_type                    OK
mysql.user                                         OK
DROP USER mysqltest1@'%';
Run mysql_upgrade with a non existing server socket
mysqlcheck: Got error: 2005: Unknown MySQL server host 'not_existing_host' (errno) when trying to connect
FATAL ERROR: Upgrade failed
set GLOBAL sql_mode='STRICT_ALL_TABLES,ANSI_QUOTES,NO_ZERO_DATE';
mysql.columns_priv                                 OK
mysql.db                                           OK
mysql.func                                         OK
mysql.help_category                                OK
mysql.help_keyword                                 OK
mysql.help_relation                                OK
mysql.help_topic                                   OK
mysql.host                                         OK
mysql.proc                                         OK
mysql.procs_priv                                   OK
mysql.tables_priv                                  OK
mysql.time_zone                                    OK
mysql.time_zone_leap_second                        OK
mysql.time_zone_name                               OK
mysql.time_zone_transition                         OK
mysql.time_zone_transition_type                    OK
mysql.user                                         OK
set GLOBAL sql_mode=default;