一、准备环境
1.主服务器A（192.168.0.176），从服务器B（192.168.0.13）。
2.两台服务器上都部署了mysql数据库。（两台服务器上的数据库版本必须是一致的）
3.再两台服务器上分别创建rb-test数据库，并创建数据表user。
二、主服务器A双机热备配置步骤
1、创建同步用户
进入mysql操作界面，在主服务器A上为从服务器建立一个连接帐户，该帐户必须授予REPLICATION SLAVE权限。因为从mysql版本3.2以后就可以通过REPLICATION对其进行双机热备的功能操作。
mysql> grant replication slave on *.* to 'zhutong'@'192.168.0.13' identified by 'zhutong#123'; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec)
2、创建好同步连接帐户后，我们可以通过在从服务器B上用zhutong帐户对主服务器A（Master）数据库进行访问下，看下是否能连接成功。
[root@ecs ~]# mysql -h192.168.0.176 -uzhutong -pzhutong#123 mysql: [Warning] Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 11 Server version: 5.7.21 MySQL Community Server (GPL) Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. mysql>
3、修改主服务器A数据库的配置
vi /etc/my.cnf #加上 server-id = 1 log-bin=mysql-bin binlog-do-db = rb binlog-ignore-db = mysql
4、重启mysql数据库
service restart mysql
5、查看主服务器的状态
[root@ecs-d68e-0003 use-tools]# mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 765 Server version: 5.7.21-log MySQL Community Server (GPL) mysql> flush table with read lock; Query OK, 0 rows affected (0.00 sec) mysql> show master statusG; *************************** 1. row *************************** File: mysql-bin.000006 Position: 154 Binlog_Do_DB: rb Binlog_Ignore_DB: mysql Executed_Gtid_Set: 1 row in set (0.00 sec) ERROR: No query specified
注意看里面的参数，特别前面两个File和Position，在从服务器（Slave）配置主从关系会有用到的。
6、锁表
注：这里使用了锁表，目的是为了产生环境中不让进新的数据，好让从服务器定位同步位置，初次同步完成后，记得解锁。
unlock tables;
三、从服务器B双机热备配置步骤
1、修改配置文件
vi /etc/my.cnf #添加如下内容 [mysqld] server-id = 2 log-bin=mysql-bin replicate-do-db = rb replicate-ignore-db = mysql,information_schema,performance_schema
2、重启数据库
service restart mysql
3.用change mster 语句指定同步位置
这步是最关键的一步了，在进入mysql操作界面后，输入如下指令：
[root@ecs-d68e-0002 DB]# mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 2 Server version: 5.7.21-log MySQL Community Server (GPL) mysql> stop slave; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> change master to master_host='192.168.0.176',master_user='zhutong',master_password='zhutong#123',master_log_file='mysql-bin.000001',master_log_pos=154; Query OK, 0 rows affected, 2 warnings (0.02 sec) #成功后，则可以开启slave线程了。 mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
4、查看从服务器（Slave）状态
mysql> show slave statusG; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.0.176 Master_User: zhutong Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000006 Read_Master_Log_Pos: 154 Relay_Log_File: ecs-d68e-0002-relay-bin.000007 Relay_Log_Pos: 367 Relay_Master_Log_File: mysql-bin.000006 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: rb Replicate_Ignore_DB: mysql,information_schema,performance_schema 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: 154 Relay_Log_Space: 795 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: Replicate_Ignore_Server_Ids: Master_Server_Id: 1 Master_UUID: 31e0c365-7e73-11e8-b6ee-fa163ee46a49 Master_Info_File: /home/zhutong/DB/datas/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec) ERROR: No query specified
查看下面两项值均为Yes，即表示设置从服务器成功。
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
四、测试同步
1、查看主从数据库中rb数据库user表的数据（我们rb数据库中只有一张表）；
主-A
mysql> use rb; Database changed mysql> show tables; +--------------+ | Tables_in_rb | +--------------+ | user | +--------------+ 1 row in set (0.01 sec) mysql> select * from user; Empty set (0.00 sec) mysql>
从-B
mysql> use rb; Database changed mysql> show tables; +--------------+ | Tables_in_rb | +--------------+ | user | +--------------+ 1 row in set (0.00 sec) mysql> select * from user; Empty set (0.00 sec)
现在可以在Master服务器中插入数据看下是否能同步。
2、在主服务器上数据库写数据，看能不能同步。
mysql> use rb; Database changed mysql> insert into user values('zbbiex','15352453201'); ERROR 1136 (21S01): Column count doesn't match value count at row 1 mysql> insert into user values(1,'zbbiex','15352453201'); Query OK, 1 row affected (0.00 sec) mysql> select * from user; +----+--------+-------------+ | id | name | mobile | +----+--------+-------------+ | 1 | zbbiex | 15352453201 | +----+--------+-------------+ 1 row in set (0.00 sec) mysql>
3、在从服务器B上查看是不是数据已经同步过去了
mysql> use rb; Database changed mysql> select * from user; +----+--------+-------------+ | id | name | mobile | +----+--------+-------------+ | 1 | zbbiex | 15352453201 | +----+--------+-------------+ 1 row in set (0.00 sec) mysql>
可以看到数据已经同步过去，完全没问题；