MySQL的master上增加Slave（2）

基于上篇文章，在master上继续挂载一个slave2到master上，可以有两钟方式，一个是直接挂载到master上，二是先从slave1获得数据库备份和master的日志文件和节点，然后再配置slave2和master关联。正常情况下，master一直在运行，为了不影响master的业务运行，我这里选择方法二。

图片来自 OReilly.MySQL.High.Availability.Tools.for.Building.Robust.Data.Centers.2nd.Edition

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1.准备slave2服务器

主机名改为slave2，IP 为 192.168.0.112

[root@slave2 ~]# hostname
slave2
[root@slave2 ~]# ifconfig eth0|grep addr
eth0      Link encap:Ethernet  HWaddr 00:0C:29:35:E0:35  
          inet addr:192.168.0.112  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe35:e035/64 Scope:Link
[root@slave2 ~]# 

2.配置slave2 的my.cnf

  log_bin=mysql-bin
  server-id=112

重启mysql 服务

[root@slave2 ~]# /etc/init.d/mysqld restart
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]

3.对slave1操作

停止slave1，并备份数据

##停止slave
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)

##查询当前master的日志和pos位置
（Relay_Master_Log_File: mysql-bin.000006 Exec_Master_Log_Pos: 304）
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: 
                  Master_Host: 192.168.0.110
                  Master_User: dbbackup
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000006
          Read_Master_Log_Pos: 304
               Relay_Log_File: slave1-relay-bin.000005
                Relay_Log_Pos: 517
        Relay_Master_Log_File: mysql-bin.000006
             Slave_IO_Running: No
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 304
              Relay_Log_Space: 891
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 

##
mysql> Flush tables with read lock;

##备份数据库
[root@slave1 tmp]# mysqldump --all-databases -uroot -p > backup.sql  

## 
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

##上传备份数据到slave2服务器/tmp下
[root@slave1 tmp]# scp backup.sql [email protected]:/tmp
The authenticity of host '192.168.0.112 (192.168.0.112)' can't be established.
RSA key fingerprint is 7a:ba:3c:38:67:1a:b5:1b:de:25:5e:6a:cc:c3:8b:ed.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.0.112' (RSA) to the list of known hosts.
root@192.168.0.112's password: 
backup.sql                                                               100%  758KB 757.9KB/s   00:00    
[root@slave1 tmp]# 

4.配置slave2

##还原数据库
[root@slave2 tmp]# mysqldump --all-databases -uroot -p < backup.sql 
或者
[root@slave2 tmp]# mysql -uroot -p< backup.sql 

 ##在slave1上show slave status\G 中找到
 Relay_Master_Log_File: mysql-bin.000006
 Exec_Master_Log_Pos: 304

然后在slave2上执行

##配置slave2 到 master
mysql> change master to
    -> master_host='192.168.0.110',
    -> master_port=3306,
    -> master_user='dbbackup',
    -> master_password='mysql.password',
    -> master_log_file='mysql-bin.000006',
    -> master_log_pos=304;
Query OK, 0 rows affected, 2 warnings (0.06 sec)
##启动slave
mysql> start slave;
Query OK, 0 rows affected (0.04 sec)

##查看slave状态
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.0.110
                  Master_User: dbbackup
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000006
          Read_Master_Log_Pos: 304
               Relay_Log_File: slave2-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000006
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 

5.测试

备注：第3步中我们把slave1停掉了，记得开启

mysql>start slave;

在master上对数据库进行操作，观察slave1和slave2是否都同步成功。