查看log，内容如下：
vim /var/log/mysqld.log
问题1：
2020-07-30T03:46:12.732170Z 2 [Warning] InnoDB: Table mysql/innodb_index_stats has length mismatch in the column name table_name. Please run mysql_upgrade
2020-07-30T03:46:13.431987Z 0 [Note] InnoDB: Buffer pool(s) load completed at 200730 11:46:13
运行：
shell: mysql_upgrade –host=’127.0.0.1′ –port=3306 –user=’root’ –password=”root”