資料庫已搭建完成，各種配置均已完成，但是在start slave ;的時候，報錯：

ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO

這裡說，我沒有配置為從機，但我明明配置過的啊。

MySQL版本：5.6.19

主：master IP  :  172.17.210.199
從：slave    IP ：172.17.206.138
先看看從機172.17.206.138的my.cnf

[[email protected] ~]# vi /etc/my.cnf
[mysqld]
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
skip-grant-tables
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
tmpdir=/tmp
[mysqld_safe]
log-error=/usr/local/data/mysqld.log
pid-file=/usr/local/mysql/data/mysqld.pid
###############以下是新增主從的配置
server_id = 2
log-bin = /usr/local/mysql/log/solve-bin.log
master-host = 172.17.210.199
master-user = test
master-pass = 123456
master-port = 3306
master-connect-retry = 60
 

這是MySQL主機172.17.210.199的my.cnf

[[email protected] ~]$ cat /etc/my.cnf
[mysqld]
log-bin = /u01/mysql/log/masters-bin.log
read-only = 0
basedir = /u01/mysql
datadir = /u01/mysql/data
port = 3306
server_id = 1
socket = /tmp/mysql.sock
join_buffer_size = 128M
sort_buffer_size = 2M
read_rnd_buffer_size = 2M

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
 

嘗試過多次 重啟主從還是報錯;
接著手動chang to 後還是一樣報錯

mysql> CHANGE MASTER TO
MASTER_HOST='172.17.210.199',
MASTER_USER='test',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='masters-bin.000003',
MASTER_LOG_POS=120;
Query OK, 0 rows affected, 2 warnings (0.04 sec) 

在從庫伺服器執行START slave;命令啟動slave

mysql> START slave;

報錯:
ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO

於是檢視日誌
1.檢視SLAVE172.17.206.138上的Mysql報錯日誌，有這麼一句：
141009  6:06:29 [ERROR] Server id not set, will not start slave

意思是，slave的server-id沒有設定。
那就奇怪了，我明明在配置檔案裡面指定了server-id的了，並且有重啟mysql服務，難道不起效？
分別在主從上執行命令“show variables like 'server_id';”。

-------從機上面檢視埠

mysql> mysql> SHOW VARIABLES LIKE 'server_id';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 0     |
+---------------+-------+
1 row in set (0.00 sec)

命名設定的是2，怎麼會變成0

-------主機上面檢視

mysql> SHOW VARIABLES LIKE 'server_id';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 1     |
+---------------+-------+
1 row in set (0.00 sec)

跟設定的一樣。
既然引數檔案不生效，就試試在資料庫命令裡面設定：在從機 172.17.206.138上執行命令

mysql > SET GLOBAL server_id=2;

再次在從機 172.17.206.138上執行slave start和show slave status，成功了。
         注意！！！由於“SET GLOBAL server_id=;”命令會在mysql服務重啟後丟失，所以一定要寫到配置檔案裡面。
但為什麼我之前修改了my.cnf檔案不起效？
仔細排查，發現配置裡面有[mysqld]和[mysqld_safe]，之前將修改的配置內容基本都放在了[mysqld_safe]下面，新增的配置檔案放的位置不一樣也有關係？於是我嘗試把配置檔案裡修改的部分放在[mysqld]下面，於是改成這樣：

[[email protected]]# cat  /etc/my.cnf
[mysqld]
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
skip-grant-tables
user=mysql
symbolic-links=0
tmpdir=/tmp
server_id = 2
log-bin = /usr/local/mysql/log/solve-bin.log
master-host = 172.17.210.199
master-user = test
master-pass = 123456
master-port = 3306
master-connect-retry = 60

[mysqld_safe]
log-error=/usr/local/data/mysqld.log
pid-file=/usr/local/mysql/data/mysqld.pid 

如圖，就是將圖中標註的內容從[mysqld_safe]下修改到[mysqld]下

修改之後，再次同步，成功了！

mysql>
mysql> STOP slave;
Query OK, 0 rows affected (0.05 sec)

mysql> START slave;
Query OK, 0 rows affected (0.00 sec)