mysql啟用skip-name-resolve模式時出現Warning的處理辦法

檢視mysql告警日誌，發現兩個警告，如下紅體字
[root@S243 ~]#  tail  -f /mysql/datadir/S243.err
2017-02-15 08:59:57 23433 [Warning] 'user' entry 'root@s243' ignored in --skip-name-resolve mode.
2017-02-15 08:59:57 23433 [Warning] 'proxies_priv' entry '@ root@s243' ignored in --skip-name-resolve mode.
2017-02-15 09:00:00 23433 [Warning] 'user' entry 'root@s243' ignored in --skip-name-resolve mode.
2017-02-15 09:00:00 23433 [Warning] 'proxies_priv' entry '@ root@s243' ignored in --skip-name-resolve mode.
2017-02-15 09:22:58 23433 [Warning] 'user' entry 'root@s243' ignored in --skip-name-resolve mode.
2017-02-15 09:22:58 23433 [Warning] 'proxies_priv' entry '@ root@s243' ignored in --skip-name-resolve mode.
2017-02-15 09:23:03 23433 [Warning] 'user' entry 'root@s243' ignored in --skip-name-resolve mode.
2017-02-15 09:23:03 23433 [Warning] 'proxies_priv' entry '@ root@s243' ignored in --skip-name-resolve mode.
網上搜到一篇文章。。。。。。，驗證確實解決了問題，於是粘過來做個記錄。

[實踐OK]mysql啟用skip-name-resolve模式時出現Warning的處理辦法 

背景：skip-name-resolve 引數的目的是不再進行反解析（ip不反解成域名），這樣可以加快資料庫的反應時間。修改配置檔案新增並需要重啟：[mysqld] skip-name-resolve新增後發現錯誤日誌有警告資訊：

[root@jackxiang mysql]# vi my.cnf

skip-name-resolve

# 禁止MySQL對外部連線進行DNS解析，使用這一選項可以消除MySQL進行DNS解析的時間。但需要注意，如果開啟該選項，

# 則所有遠端主機連線授權都要使用IP地址方式，否則MySQL將無法正常處理連線請求

實踐如下：

重啟mysql，發現日誌還有:

1）按提示作下查詢，果然有一個空賬戶和root帳戶的Host是jackxiang：

select * from user where Host="jackxiang"\G;

mysql> select Host,User,Password from user where Host="jackxiang";

+-----------+------+-----------------------------------------------------+

| Host          | User  | Password                              |

+-----------+------+-----------------------------------------------------+

| jackxiang  |           |                                                                            |

| jackxiang |root      | *2CD42BDFDF0EB0E*Z****3458EB72EE1F17F26F |

+-----------+------+------------------------------------------------------+

2）查下localhost，因為大都是限定本機連線，不讓外面機器連線，確保安全：

mysql> select Host,User,Password from user where Host="localhost" limit 2;

+-----------+-----------------+-------------------------------------------+

| Host      | User                     | Password                                               |

+-----------+-----------------+-------------------------------------------+

| localhost |                           |                                                               |

| localhost | jack_mysql          | *2CD42BDFDF0E***3458EB72EE1F17F26F |

+-----------+-----------------+-------------------------------------------+

3）把Host既是 jackxiang的，使用者是空或root的Host修改為localhost：

mysql> update user set Host="localhost" where Host="jackxiang";

ERROR 1062 (23000): Duplicate entry 'localhost-' for key 'PRIMARY'

這樣搞不行，得一個一個幹掉，看有沒有root同名的，查下：

mysql> select Host,User,Password from user where User="";

+-----------+------+----------+

| Host      | User | Password |

+-----------+------+----------+

| localhost |            |               |

| jackxiang |            |               |

+-----------+------+----------+

mysql> delete from user where  User="" and Password="";

Query OK, 2 rows affected (0.01 sec)

4)查下user為root的

mysql> select Host,User,Password from user where User="root";                                      

+-----------+------+-------------------------------------------+

| Host      | User | Password                                  |

+-----------+------+-------------------------------------------+

| localhost | root | *2CD42BDFDF0EB0E1A7777777777EE1F17F26F |

| jackxiang | root | *2CD42BDFDF0EB0E1A7777777777EE1F17F26F |

| 127.0.0.1 | root | *2CD42BDFDF0EB0E1A7777777777EE1F17F26F |

| ::1       | root | *2CD42BDFDF0EB0E1A7777777777EE1F17F26F |

+-----------+------+-------------------------------------------+

5)留下localhost就足夠了，其餘刪除掉：

mysql> delete from user where Host !="localhost" and User="root";

Query OK, 3 rows affected (0.00 sec)

6)restart mysql:

日誌warning還有一個：

[Warning] 'proxies_priv' entry '@ root@jackxiang' ignored in --skip-name-resolve mode.

解決辦法：

然後刪除表mysql.proxies_priv中和cvs類似與具體域名有關的行,方法同上。

mysql> select Host,User,Proxied_host,Proxied_user,With_grant,Grantor,Timestamp from proxies_priv ;

+-----------+------+--------------+--------------+------------+---------+----------------+

| Host      | User | Proxied_host | Proxied_user | With_grant | Grantor | Timestamp           |

+-----------+------+--------------+--------------+------------+---------+----------------+

| localhost | root |              |              |                              1 |         | 2014-07-14 13:26:08 |

| jackxiang | root |              |              |                              1 |         | 2014-07-14 13:26:08 |

+-----------+------+--------------+--------------+------------+---------+----------------+

mysql> delete from proxies_priv where Host="jackxiang";

Query OK, 1 row affected (0.02 sec)

這下徹底清靜了。

原來是當時安裝mysql後，多次grant授權引起的,。

備註：

  skip-name-resolve是禁用dns解析，避免網路DNS解析服務引發訪問MYSQL的錯誤，一般應當啟用。   啟用後，在mysql的授權表中就不能使用主機名了，只能使用IP ，出現此警告是由於mysql 表中已經存在有 root@jackxiang 帳號資訊。     我們把它刪除就好了。   mysql>use mysql; mysql> delete  from user where HOST='localhost.localdomain'; Query OK, 2 rows affected (0.00 sec)   重啟MYSQL ，發現警告已經沒有啦。