在主从的基础上，改为互为主从。需要注意某些配置文件。

A库配置文件

/etc/my.cnf

[mysqld]

basedir =/usr/local/mysql

datadir =/datal/mysql/data

port = 3306

server_id = 1

log-bin= mysql-bin

binlog_format = mixed

read-only=0

#binlog-do-db=test

binlog-ignore-db=mysql

binlog-ignore-db=information_schema

binlog-ignore-db=performance_schema

auto-increment-offset=1

auto-increment-increment=2

#设置自增参数ID初始为1，不长2，也就是A库的自动ID为1、3、5、7、9。。。

#主主复制的从库设置（新增）

#replicate-do-db=test

replicate-ignore-db=mysql

replicate-ignore-db=information_schema

replicate-ignore-db=performance_schema

relay_log=mysql-relay-bin

log-slave-updates=on

B库配置文件

/etc/my.cnf

[mysqld]

basedir =/usr/local/mysql

datadir =/data/mysql/data

port = 3306

server_id = 2

log-bin= mysql-bin

binlog_format = mixed

read-only=0

#replicate-do-db=test

replicate-ignore-db=mysql

replicate-ignore-db=information_schema

replicate-ignore-db=performance_schema

relay_log=mysql-relay-bin

log-slave-updates=on

#主主复制的主库设置（新增）

#binlog-do-db=test

binlog-ignore-db=mysql

binlog-ignore-db=information_schema

binlog-ignore-db=performance_schema

auto-increment-offset=2

auto-increment-increment=2

 

#设置自增ID初始值为2，步长为2，也就是B库的自增ID为2、4、6、8、10、、、