MySQL主从架构之Master-Master互为主备

Master-Master互为主备

1：按照主从配置步骤将MasterB配置成MasterA的从库；

参考我这篇文章：http://www.cnblogs.com/xiaoit/p/3977843.html

2：确保MasterB没有写入，通过show master status命令在MasterB上得到其同步点，再将MasterA配置成MasterB的从库。

通常，为了简化逻辑，其中一个Master会设置为只读，正常只通过另外一个Master进行读写。 若要两边都写，为了避免自增id冲突，一般会设置奇偶错开，即一台的自增ID均为奇数，另一台均为偶数。

这里假设你已经按照我第一篇文章做了主从。

配置实例：

1：在Master B（Slave）的配置文件中添加

port = 3307
log_bin = /var/lib/mysql/mysql-binlog
binlog_do_db = testSM

2：在MasterA（Master）的配置文件中添加

prot=3306
master-host = 10.4.5.9
master-user = gechong1
master-password = gechong1
master-port = 3307
master-connect-retry = 5
replicate-do-db = testSM

3：在Master B（Slave）上创建复制账号gechong1

GRANT REPLICATION SLAVE ON *.* TO gechong1@'%' IDENTIFIED BY 'gechong1';

4：两边都重启服务登陆数据库

在Master A（Master）上查看

mysql> show master status;
+---------------------+----------+--------------+------------------+
| File                | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+---------------------+----------+--------------+------------------+
| mysql-binlog.000002 |      106 | test         |                  |
+---------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql> show slave status G
*************************** 1. row ***************************
               Slave_IO_State: Connecting to master
                  Master_Host: 10.4.5.9
                  Master_User: gechong1
                  Master_Port: 3306
                Connect_Retry: 5
              Master_Log_File: 
          Read_Master_Log_Pos: 4
               Relay_Log_File: mysqld-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: 
             Slave_IO_Running: No
            Slave_SQL_Running: Yes
              Replicate_Do_DB: test
          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: 0
              Relay_Log_Space: 106
              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: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 2013
                Last_IO_Error: error connecting to master 'gechong1@10.4.5.9:3306' - retry-time: 5  retries: 86400
               Last_SQL_Errno: 0
               Last_SQL_Error: 
1 row in set (0.00 sec)

在MasterB（Slave）上查看

mysql> show slave status G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.4.14.168
                  Master_User: gechong
                  Master_Port: 3306
                Connect_Retry: 5
              Master_Log_File: mysql-binlog.000002
          Read_Master_Log_Pos: 106
               Relay_Log_File: mysqld-relay-bin.000006
                Relay_Log_Pos: 254
        Relay_Master_Log_File: mysql-binlog.000002
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: test
          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: 106
              Relay_Log_Space: 558
              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: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
1 row in set (0.00 sec)

mysql> show master status;
+---------------------+----------+--------------+------------------+
| File                | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+---------------------+----------+--------------+------------------+
| mysql-binlog.000001 |      327 |              |                  |
+---------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

　　

可以看到  Master A：Slave_IO_Running: No

可以参照第一篇文档，重新配置参数即可。