在安装MySQL 5.6.30时，安装完成后，后台日志报如下警告信息：
2016-05-27 12:25:27 7fabf86f7700 InnoDB: Error: Table “mysql”.”innodb_table_stats” not found.
2016-05-27 12:25:27 7fabf86f7700 InnoDB: Error: Fetch of persistent statistics requested for table “hj_web”.”wechat_res” but the required system tables mysql.innodb_table_stats and mysql.innodb_index_stats are not present or have unexpected structure. Using transient stats instead.

2016-05-27 14:03:52 28585 [Warning] InnoDB: Cannot open table mysql/slave_master_info from the internal data dictionary of InnoDB though the .frm file for the table exists. See http://dev.mysql.com/doc/refman/5.6/en/innodb-troubleshooting.html for how you can resolve the problem.

2016-05-27 14:03:52 28585 [Warning] InnoDB: Cannot open table mysql/slave_relay_log_info from the internal data dictionary of InnoDB though the .frm file for the table exists. See http://dev.mysql.com/doc/refman/5.6/en/innodb-troubleshooting.html for how you can resolve the problem.

2016-05-27 14:03:52 28585 [Warning] InnoDB: Cannot open table mysql/slave_worker_info from the internal data dictionary of InnoDB though the .frm file for the table exists. See http://dev.mysql.com/doc/refman/5.6/en/innodb-troubleshooting.html for how you can resolve the problem.

问题产生原因：具体原因目前不详，网上查找到的资料:数据库打开这几张表的默认引擎为MyISAM，但是这几张表在建表时的引擎为INNODB

但是能确定的，这几张表确实是在mysql5.6中新入的
innodb_index_stats,
innodb_tables_stats,
slave_master_info,
slave_relay_log_info,
slave_worker_info

解决方法：
1、登录数据库，进入mysql库，执行如下SQL删除5张表
记住，一定要是drop table if exists
mysql> use mysql;
mysql> drop table if exists innodb_index_stats;
mysql> drop table if exists innodb_table_stats;
mysql> drop table if exists slave_master_info;
mysql> drop table if exists slave_relay_log_info;
mysql> drop table if exists slave_worker_info;
执行完后，可以用show tables查看一下，看表的数据是否已经比删除之前减少了，如果减少了，说明你成功了！

2、上一步操作完成后，停止数据库，并进入到数据库数据文件所在目录，删除上面5个表所对应的idb文件，如下所示：

# /etc/init.d/mysqld stop
# cd /data/mysql/data/mysql/
# ls -l *.ibd
-rw-rw—- 1 mysql mysql 98304 May 27 14:17 innodb_index_stats.ibd
-rw-rw—- 1 mysql mysql 98304 May 27 14:17 innodb_table_stats.ibd
-rw-rw—- 1 mysql mysql 98304 May 27 14:14 slave_master_info.ibd
-rw-rw—- 1 mysql mysql 98304 May 27 14:14 slave_relay_log_info.ibd
-rw-rw—- 1 mysql mysql 98304 May 27 14:14 slave_worker_info.ibd

# /bin/rm -rf *.ibd

3、重新启动数据库，进入到mysql库，重建上面被删除的表结构：
数据库的建表脚本在mysql软件的安装目录的share目录下或者mysql的安装包的script目录下，我的mysql软件的安装路径为/data/mysql/

# /etc/init.d/mysqld start
mysql> use mysql;
mysql> source /data/mysql/share/mysql_system_tables.sql
mysql> show tables;
+—————————+
| Tables_in_mysql |
+—————————+
| columns_priv |
| db |
| event |
| func |
| general_log |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+—————————+
28 rows in set (0.00 sec)

mysql> desc innodb_table_stats;
+————————–+———————+——+—–+——————-+—————————–+
| Field | Type | Null | Key | Default | Extra |
+————————–+———————+——+—–+——————-+—————————–+
| database_name | varchar(64) | NO | PRI | NULL | |
| table_name | varchar(64) | NO | PRI | NULL | |
| last_update | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| n_rows | bigint(20) unsigned | NO | | NULL | |
| clustered_index_size | bigint(20) unsigned | NO | | NULL | |
| sum_of_other_index_sizes | bigint(20) unsigned | NO | | NULL | |
+————————–+———————+——+—–+——————-+—————————–+
6 rows in set (0.00 sec)

mysql> desc slave_master_info;
+————————+———————+——+—–+———+——-+
| Field | Type | Null | Key | Default | Extra |
+————————+———————+——+—–+———+——-+
| Number_of_lines | int(10) unsigned | NO | | NULL | |
| Master_log_name | text | NO | | NULL | |
| Master_log_pos | bigint(20) unsigned | NO | | NULL | |
| Host | char(64) | NO | PRI | | |
| User_name | text | YES | | NULL | |
| User_password | text | YES | | NULL | |
| Port | int(10) unsigned | NO | PRI | NULL | |
| Connect_retry | int(10) unsigned | NO | | NULL | |
| Enabled_ssl | tinyint(1) | NO | | NULL | |
| Ssl_ca | text | YES | | NULL | |
| Ssl_capath | text | YES | | NULL | |
| Ssl_cert | text | YES | | NULL | |
| Ssl_cipher | text | YES | | NULL | |
| Ssl_key | text | YES | | NULL | |
| Ssl_verify_server_cert | tinyint(1) | NO | | NULL | |
| Heartbeat | float | NO | | NULL | |
| Bind | text | YES | | NULL | |
| Ignored_server_ids | text | YES | | NULL | |
| Uuid | text | YES | | NULL | |
| Retry_count | bigint(20) unsigned | NO | | NULL | |
| Ssl_crl | text | YES | | NULL | |
| Ssl_crlpath | text | YES | | NULL | |
| Enabled_auto_position | tinyint(1) | NO | | NULL | |
+————————+———————+——+—–+———+——-+
23 rows in set (0.00 sec)

说明表都正常了，再次查看mysql报错日志，就会发现没有了关于这5个表的报错日志。