After the author upgraded mysql5.5 to 5.7, he encountered two errors and started to fill in the pits.
1. Start the mysql service and report an error
Execute service mysqld start and report an error:
Starting mysqld (via systemctl): Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
1) Check the log, only look at the error
cat /var/log/mysqld.logDiscover:
[ERROR] Can’t start server: Bind on TCP/IP port: Address already in use
[ERROR] Do you already have another mysqld server running on port: 3306
Translation: The port is occupied, have you already run other mysqld services occupying 3306
2) Check the port status
netstat -apn | grep 3306Discover:
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 7461/mysqld
solve:
kill 7461
service mysqld restart2. An error is reported when changing the password
Execute set password for 'root'@'localhost' =password('root'); Error:
ERROR 3009 (HY000): Column count of mysql.user is wrong. Expected 45, found 42. Created with MySQL 50568, now running 50737. Please use mysql_upgrade to fix this error.
1) After manually upgrading mysql, the data structure has changed, so it must be upgraded through instructions
mysql> quit
mysql_upgrade
service mysqld restartAt this point, the author window returns:
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
mysql_upgrade: (non fatal) [ERROR] 1728: Cannot load from mysql.proc. The table is probably corrupted
mysql_upgrade: (non fatal) [ERROR] 1545: Failed to open mysql.event
Checking system database.
mysql.columns_priv OK
mysql.db OK
mysql.engine_cost OK
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.gtid_executed OK
mysql.help_category OK
mysql.help_keyword OK
mysql.help_relation OK
mysql.help_topic OK
mysql.host OK
mysql.innodb_index_stats OK
mysql.innodb_table_stats OK
mysql.ndb_binlog_index OK
mysql.plugin OK
mysql.proc OK
mysql.procs_priv OK
mysql.proxies_priv OK
mysql.server_cost OK
mysql.servers OK
mysql.slave_master_info OK
mysql.slave_relay_log_info OK
mysql.slave_worker_info OK
mysql.slow_log 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
Upgrading the sys schema.
Checking databases.
sys.sys_config OK
Upgrade process completed successfully.
Checking if update is needed.2) Install mysql for the first time, log in to the database and directly enter without entering a password
mysql -u root -p
# 直接按回车
mysql> set password for 'root'@'localhost' =password('root');
# 设置数据库用户root的密码为root3) Test login password
mysql> exit
mysql -u root -p
Enter password:
# 输入root，并回车
# 登录成功！