I've upgraded one of the slave server from mysql 5.6 to 5.7 and now 5.7 to 8. But after up-gradation steps done when i use systemctl start mysqld.service or systemctl restart mysqld facing error and mysql is not starting. In error log i am getting following errors :
2019-01-16T15:32:05.808246Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.13) starting as process 22860
2019-01-16T15:32:14.328460Z 2 [ERROR] [MY-013140] [Server] Failed to add the foreign key constraint. Missing index for constraint 'columnsname_ibfk' in the referenced table 'table_name'
2019-01-16T15:32:15.692313Z 2 [Warning] [MY-010772] [Server] db.opt file not found for test database. Using default Character set.
2019-01-16T15:32:15.975759Z 0 [ERROR] [MY-010022] [Server] Failed to Populate DD tables.
2019-01-16T15:32:15.975874Z 0 [ERROR] [MY-010119] [Server] Aborting
2019-01-16T15:32:18.083808Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.13) MySQL Community Server - GPL.
If i can start mysql then i can run upgrade command to upgrade mysql :
mysql_upgrade -uroot -p**** --upgrade-system-tables