主机环境说明。master1: 10.8.1.11master2: 10.8.1.12版本信息： [root@m1 ~]# mysql -V mysql Ver 14.14 Distrib 5.6.27, for Linux (x86_64) using EditLine wrapper1、主库开启bin-log功能，配置server-id修改my.cf配置文件，开启bin-log功能，配置server-id。

    [root@m1 ~]# more /etc/my.cnf        # For advice on how to change settings please see    # dev.mysql/doc/refman/5.6/en/server-configuration-defaults.html        [mysqld]    server-id = 1    datadir = /var/lib/mysql    log_bin = /var/lib/mysql/bin-log    socket = /var/lib/mysql/mysql.sock    slave_net_timeout = 60    log-slave-updates    slave-skip-errors=all    skip-name-resolve    sync_binlog=1    auto_increment_increment=2    auto_increment_offset=1        sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES    #salve-net-timeout默认是3600秒，缩短时间是为了防止双YES的假象#（事实上我已遇到，参考地址：cnblogs/billyxp/p/3470376.html）如果要指定同步或不同步哪些库，可使用如下参数#binlog-do-db=osyunweidb   #需要同步的数据库名，如果有多个数据库，可重复此参数，每个数据库一行#binlog-ignore-db=mysql    #不同步mysql系统数据库

至于这些参数的说明具体看手册。红色的部分非常重要，如果一个MASTER 挂掉的话，另外一个马上接管。紫红色的部分指的是服务器频繁的刷新日志。这个保证了在其中一台挂掉的话，日志刷新到另外一台。从而保证了数据的同步2、确认bin-log与server-id是否开启：查看命令 show variables like 'log_bin'; show variables like 'server_id';

mysql> show variables like 'log_bin';+---------------+-------+|Variable_name | Value |+---------------+-------+|log_bin       | ON   |+---------------+-------+1 rowin set (0.00 sec)mysql>show variables like 'server_id';+---------------+-------+|Variable_name | Value |+---------------+-------+|server_id     | 1     |+---------------+-------+1 rowin set (0.00 sec)

3、创建复制授权用户mysql> grant replication slave on *.* to replication@'%'identified by '123456'; #授权该用户对所有表都能进行复制mysql>flush privileges; #刷新权限4、锁表，记录log-bin文件名和位置

mysql>flush tables with read lock;     #锁定所有表，此时数据库不能写入数据QueryOK, 0 rows affected (0.05 sec)mysql>show master status;      #查看最新bin-log文件及位置+------------------------+------------+-------------------+-------------------------+|File                   | Position   | Binlog_Do_DB      | Binlog_Ignore_DB        |+------------------------+------------+-------------------+-------------------------+|mysql-bin.000001       |  26314    |                   |                        |+------------------------+------------+-------------------+-------------------------+1row in set (0.00 sec)

5、锁表状态全备mysql数据由于退出当前mysql登陆窗口，锁表功能就失效，需克隆一个会话进行全备。#mysqldump-uroot -p -A -B > /tmp/mysql_bak_2015_11_17.sql看下备份数据大小，确认备份成功。 [root@m1 ~]# ls -l mysql_bak_2015_11_17.sql -rw-r--r--. 1 root root 645327 Nov 18 06:27 mysql_bak_2015_11_17.sql [root@m1 ~]#6、解除锁表mysql>unlock tables;或直接quit退出即可。7、从库开启bin-log功能，配置server-id从库开启bin-log功能后，待会在主上在配置同步，互为主从就完成了。

[root@m2 ~]# vi /etc/my.cnf        # For advice on how to change settings please see    # dev.mysql/doc/refman/5.6/en/server-configuration-defaults.html        [mysqld]    server-id = 2    datadir = /var/lib/mysql    log_bin = /var/lib/mysql/mysql-bin    socket = /var/lib/mysql/mysql.sock    slave_net_timeout = 60    log-slave-updates    slave-skip-errors=all    skip-name-resolve    sync_binlog=1    auto_increment_increment=2    auto_increment_offset=2        sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES#salve-net-timeout默认是3600秒，缩短时间是为了防止双YES的假象

#至于这些参数的说明具体看手册。红色的部分非常重要，如果一个MASTER 挂掉的话，另外一个马上接管。紫红色的部分指的是服务器频繁的刷新日志。这个保证了在其中一台挂掉的话，日志刷新到另外一台。从而保证了数据的同步#/etc/init.d/mysql restart8、确认从库bin-log与server-id是否开启查看命令 show variables like 'log_bin'; show variables like 'server_id';

mysql>show variables like 'log_bin';+---------------+-------+|Variable_name | Value |+---------------+-------+|log_bin       | ON    |+---------------+-------+1row in set (0.00 sec)mysql>show variables like 'server_id';+---------------+-------+|Variable_name | Value |+---------------+-------+|server_id     | 2     |+---------------+-------+1row in set (0.00 sec)

9、从库导入主库的全备数据登陆mysql导入数据mysql>source /root/mysql_bak_2015_11_17.sql10、记录从库bin-log信息因为在从库导入全备数据时，此时主库与从库的内容是一致的，但是bin-log位置不一定一致。

mysql>show master status;      #查看最新bin-log文件及位置+------------------------+------------+-------------------+-------------------------+|File                   |Position   | Binlog_Do_DB      | Binlog_Ignore_DB        |+------------------------+------------+-------------------+-------------------------+|mysql-bin.000003       |  2328055   |                   |                        |+------------------------+------------+-------------------+-------------------------+1row in set (0.00 sec)

11、从库设置同步主库此处binlog文件与位置状态，是主库在步骤4锁表时show master status查看的位置状态。

CHANGE MASTER TO MASTER_HOST='10.8.1.11',MASTER_PORT=3306,MASTER_USER='replication',MASTER_PASSWORD='123456',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=26314;

12、开启从库同步并确认同步是否成功使用start slave开启同步功能，使用show slave status\G查看同步是否成功

mysql>start slave;QueryOK, 0 rows affected (0.00 sec)mysql>show slave status\G   #\G不按表格输出***************************1. row ***************************               Slave_IO_State: Waiting formaster to send event                  Master_Host: 10.0.0.2                  Master_User: replication                  Master_Port: 8306                Connect_Retry: 60              Master_Log_File: mysql-bin.000001          Read_Master_Log_Pos: 136270               Relay_Log_File:mysqld-relay-bin.000002                Relay_Log_Pos: 72697        Relay_Master_Log_File: mysql-bin.000001             Slave_IO_Running:Yes            Slave_SQL_Running:Yes              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: 98758              Relay_Log_Space: 110366              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: 622   #查看主从同步延迟，延迟大则可能需要优化Master_SSL_Verify_Server_Cert:No                Last_IO_Errno: 0                Last_IO_Error:               Last_SQL_Errno: 0               Last_SQL_Error:  Replicate_Ignore_Server_Ids:             Master_Server_Id: 11row in set (0.00 sec)

#sql线程与IO线程都是YES，slave配置成功。13、主库设置同步从库由于从库是全备导入，原先在主库上配置的复制帐户也同样导入，所以这里不用在从库上新授权复制用户。从库上的binlog文件与位置状态，是从库在刚导入时show master status查看到的位置状态。

CHANGEMASTER TO MASTER_HOST='10.8.1.12',MASTER_PORT=3306,MASTER_USER='replication',MASTER_PASSWORD='123456',MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=2328055;#修改相应信息，直接把这些配置在mysql中粘贴即可。

14、开启同步并确认同步是否成功使用start slave开启同步功能，使用show slave status\G查看同步是否成功

mysql>start slave;QueryOK, 0 rows affected (0.00 sec)mysql>show slave status\G***************************1. row ***************************               Slave_IO_State: Waiting formaster to send event                  Master_Host: 172.16.0.2                  Master_User: replication                  Master_Port: 3306                Connect_Retry: 60              Master_Log_File: mysql-bin.000007          Read_Master_Log_Pos: 107               Relay_Log_File:mysqld-relay-bin.000006                Relay_Log_Pos: 253        Relay_Master_Log_File: mysql-bin.000007             Slave_IO_Running: Yes            Slave_SQL_Running:Yes              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: 107              Relay_Log_Space: 556              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: 0Master_SSL_Verify_Server_Cert:No                Last_IO_Errno: 0                Last_IO_Error:               Last_SQL_Errno: 0               Last_SQL_Error:  Replicate_Ignore_Server_Ids:             Master_Server_Id: 21row in set (0.00 sec)

#IO线程与sql线程都是正常。15、互为主从测试在两台mysql各创建一个库，看两边是否都能进行同步。分别在主库上执行 create database test01;从库上执行create database test02;看两台数据库上执行show databases;，看是否都有test01表和test02表。我的经过测试，双主测试成功。