下文给大家带来有关实战演示MySQL 5.7.17实现主从复制内容，相信大家一定看过类似的文章。我们给大家带来的有何不同呢？一起来看看正文部分吧，相信看完实战演示MySQL 5.7.17实现主从复制你一定会有所收获。
主从复制的原理：
分为同步复制和异步复制，实际复制架构中大部分为异步复制。 复制的基本过程如下：
1).Slave上面的IO进程连接上Master，并请求从指定日志文件的指定位置（或者从最开始的日志）之后的日志内容；
2).Master接收到来自Slave的IO进程的请求后，通过负责复制的IO进程根据请求信息读取制定日志指定位置之后的日志信息，返回给Slave 的IO进程。返回信息中除了日志所包含的信息之外，还包括本次返回的信息已经到Master端的bin-log文件的名称以及bin-log的位置；
3).Slave的IO进程接收到信息后，将接收到的日志内容依次添加到Slave端的relay-log文件的最末端，并将读取到的Master端的 bin-log的文件名和位置记录到master-info文件中，以便在下一次读取的时候能够清楚的告诉Master“我需要从某个bin-log的哪个位置开始往后的日志内容，请发给我”；
4).Slave的Sql进程检测到relay-log中新增加了内容后，会马上解析relay-log的内容成为在Master端真实执行时候的那些可执行的内容，并在自身执行。
一、环境准备
操作系统版本：centos 7.2
云服务器架构：
Master(主) ip：192.168.2.70 主机名称：node01 server_id:1
Slave(从) ip：192.168.2.71 主机名称：node02 server_id:2
Slave(从) ip：192.168.2.5 主机名称：node03 server_id:3
其他准备：
每台云服务器配置以下hosts
# vim /etc/hosts
192.168.2.70 node01
192.168.2.71 node02
192.168.2.5 node03
系统时间同步:
#yum install chrony
配置时间同步源：# vi /etc/chrony.conf
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
server 0.rhel.pool.ntp.org iburst
server 1.rhel.pool.ntp.org iburst
# systemctl start chronyd.service #启动
# chronyc sources -v #同步时间源
关闭selinux
关闭firewalld防火墙
准备测试数据库apps.sql
解决依赖关系:yum -y install gcc gcc-c++ ncurses ncurses-devel cmake bison
先移除:rpm -e --nodeps mariadb-libs-5.5.44-2.el7.centos.x86_64
新建目录/mydata/data(建议使用lvm2镜像，实现物理备份)，存放数据库数据
mysql 安装部署请参照http://daisywei.blog.51cto.com/7837970/1896614 (这里不再阐述)
二、SSH密钥登录方式设置
在node01节点192.168.2.70操作：
[root@node01 ~]# ssh-keygen -t rsa
[root@node01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.2.71
[root@node01 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.2.5在node02节点192.168.2.71操作：
[root@node02 ~]# ssh-keygen -t rsa
[root@node02 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.2.70
[root@node02 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.2.5在node03节点192.168.2.5操作：
[root@node03 ~]# ssh-keygen -t rsa
[root@node03 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.2.70
[root@node03 ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.2.71三、搭建主从复制架构
1、node01、node02、node03安装mysql,并初始化数据库(省略)
2、默认安装mysql有随机生成密码，node01、node02、node3节点上数据库设置管理员密码(测试密码：111111)，同时创建复制使用的账号repl(密码111111)
#授权192.168.2.%网段主机root用户访问任意库，本地登录密码
mysql> SET PASSWORD = PASSWORD('111111');
mysql> UPDATE user SET host='192.168.2.%' where user = 'root';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhsot' IDENTIFIED BY '111111';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.2.%' IDENTIFIED BY '111111';
mysql> grant replication slave on *.* to 'repl'@'%' identified by '111111';
mysql> FLUSH PRIVILEGES;3、node01(192.168.2.70)master配置mysql文件my.cnf(修改前建议备份该文件)修改如下内容,修改配置后重启数据库：
[mysqld]
datadir = /mydata/data #数据存放目录
socket = /tmp/mysql.sock #socket
innodb_file_per_table = ON #开启独立的表空间
skip_name_resolve = ON #禁用dns解析
log_bin = mysql-bin #开启日志(日志存储位置尽量不要同数据存储同一磁盘同一目录，这里测试方便不重新指向)
relay_log = relay-bin #开启中继日志 (日志存储位置尽量不要同数据存储同一磁盘同一目录，这里测试方便不重新指向)
binlog-format = row #日志格式
log-slave-updates = true # 配置从云服务器的更新写入二进制日志
sever_id = 1 #server_id一定要唯一；
[root@node01 ~]# systemctl restart mysqld.service #重启服务注意：日志格式，binlog的格式也有三种：STATEMENT，ROW，MIXED。
mysql> show variables like 'log_%'; #查看日志是否开启binlog-do-db 和 replicate-ignore-db 必须相同
log_bin、relay_log，二进制日志和中继日志尽量不要跟数据存储放在同一磁盘同一目录，防止硬盘损坏时日志也丢失
4、node01(192.168.2.70)master导入测试数据库apps.sql
mysql> CREATE DATABASE apps;
Query OK, 1 row affected (0.00 sec)
mysql> use apps;
Database changed
mysql> source /home/soft/apps.sql5、node02(192.168.2.71)slave配置mysql文件my.cnf修改如下内容,修改配置后重启数据库：
[mysqld]
datadir = /mydata/data
socket = /tmp/mysql.sock #socket
innodb_file_per_table = ON
skip_name_resolve = ON
log_bin = mysql-bin
relay_log = relay-bin
binlog-format = row
log-slave-updates = true
sever_id = 2
#relay_log_purge=0 #禁止自动删除中继日志(slave配置文件多了下面这两条），如果是MHA开启此项
[root@node02 ~]# systemctl restart mysqld.service #重启服务
[root@node02 ~]#mysql -uroot -p111111 -e "set global read_only=1" #从库只读，不建议写在配置文件中6、node03(192.168.2.5)slave配置mysql文件my.cnf修改如下内容,修改配置后重启数据库：
[mysqld]
datadir = /mydata/data
socket = /tmp/mysql.sock #socket
innodb_file_per_table = ON
skip_name_resolve = ON
log_bin = mysql-bin
relay_log = relay-bin
binlog-format = row
log-slave-updates = true
sever_id = 3
#relay_log_purge=0 #禁止自动删除中继日志(slave配置文件多了下面这两条），如果是MHA开启此项
[root@node03 ~]# systemctl restart mysqld.service #重启服务
[root@node03 ~]#mysql -uroot -p111111 -e "set global read_only=1" #从库只读，不建议写在配置文件中7、在node01(192.168.2.70)Master上备份一份完整的数据：
[root@node01 /]# mysqldump -uroot -p111111 -h292.168.2.70 --master-data=2 --single-transaction -R --triggers -A > /home/soft/all.sql;说明：
--master-data=2代表备份时刻记录master的Binlog位置和Position
--single-transaction意思是获取一致性快照
-R意思是备份存储过程和函数
--triggres的意思是备份触发器
-A代表备份所有的库
查看更多信息mysqldump --help
8、在node01(192.168.2.70)Master上创建复制用户repl（密码111111），并授权访问所有主机:
mysql> grant replication slave on *.* to 'repl'@'%' identified by '111111';
mysql> flush privileges; #刷新缓存9、查看node01(192.168.2.70)Master主库备份时的binlog名称和位置，MASTER_LOG_FILE和MASTER_LOG_POS：
[root@node01 soft]# head -n 30 /home/soft/all.sql | grep 'CHANGE MASTER TO'
-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=154;10、把node01 Master主库备份all.sql复制到从库node01(192.168.2.71)和node3(192.168.2.5)/home/soft/目录下，并且导入到从库中
[root@node01 /]# scp /home/soft/all.sql root@192.168.2.71:/home/soft/
[root@node01 /]# scp /home/soft/all.sql root@192.168.2.5:/home/soft/11、从库node02，node3导入all.sql，并设置复制参数
[root@node02 /]# mysql -uroot -p111111 -h292.168.2.71 < /home/soft/all.sql
[root@node03 /]# mysql -uroot -p111111 -h292.168.2.5 < /home/soft/all.sqlmysql> CREATE DATABASE apps;
mysql> use apps;
Database changed
mysql> source /home/soft/all.sqlnode02和node03，连接mysql，执行以下命令：
[root@node02 /]# mysql -uroot -p111111 -h292.168.2.71mysql> stop slave; #暂停从库
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> CHANGE MASTER TO MASTER_HOST='192.168.2.70',MASTER_USER='repl', MASTER_PASSWORD='111111',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=154;
Query OK, 0 rows affected, 2 warnings (0.04 sec)说明：MASTER_HOST #主库 ，MASTER_USER和MASTER_PASSWORD #复制账号密码 ，CHANGE MASTER TO #还原同步文件和日志
mysql> start slave; #启动复制
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G #查看复制状态
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.70
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 154
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 320
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: 154
Relay_Log_Space: 521
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: 4c9775f6-ef61-11e6-9973-5297c04d0733
Master_Info_File: /mydata/data/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)======================================================
[root@node03 /]# mysql -uroot -p111111 -h292.168.2.5mysql> stop slave; #暂停从库
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> CHANGE MASTER TO MASTER_HOST='192.168.2.70',MASTER_USER='repl', MASTER_PASSWORD='111111',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=154;
Query OK, 0 rows affected, 2 warnings (0.04 sec)
说明：MASTER_HOST #主库 ，MASTER_USER和MASTER_PASSWORD #复制账号密码 ，CHANGE MASTER TO #还原同步文件和日志
mysql> start slave; #启动复制
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G #查看复制状态
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.70
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 154
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 320
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: 154
Relay_Log_Space: 521
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: 4c9775f6-ef61-11e6-9973-5297c04d0733
Master_Info_File: /mydata/data/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 (0.01 sec)12、验证复制是否正常！
############主库node01 Master插入一行数据，并查看Position号
mysql> INSERT INTO apps (app_name,url,country) VALUES ('BAIDU','http://www.baidu.com','CN');
Query OK, 1 row affected (0.00 sec)
mysql> show master status \G
*************************** 1. row ***************************
File: mysql-bin.000001
Position: 449
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)#######从库node02 slave查看是否已经同步存在，Position号是否与主库master一致
mysql> SELECT * from apps;
+----+------------+-------------------------+---------+
| id | app_name | url | country |
+----+------------+-------------------------+---------+
| 1 | QQ APP | http://im.qq.com/ | CN |
| 2 | 微博 APP | http://weibo.com/ | CN |
| 3 | 淘宝 APP | https://www.taobao.com/ | CN |
| 4 | BAIDU | http://www.baidu.com | CN |
+----+------------+-------------------------+---------+
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.70
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 449 #与主库Position一致
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 615
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: 449
Relay_Log_Space: 816
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: 4c9775f6-ef61-11e6-9973-5297c04d0733
Master_Info_File: /mydata/data/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)########从库node03 slave查看是否已经同步存在，Position号是否与主库master一致
mysql> SELECT * from apps;
+----+------------+-------------------------+---------+
| id | app_name | url | country |
+----+------------+-------------------------+---------+
| 1 | QQ APP | http://im.qq.com/ | CN |
| 2 | 微博 APP | http://weibo.com/ | CN |
| 3 | 淘宝 APP | https://www.taobao.com/ | CN |
| 4 | BAIDU | http://www.baidu.com | CN |
+----+------------+-------------------------+---------+
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.70
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 449 #与主库Position保持一致
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 615
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: 449
Relay_Log_Space: 816
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: 4c9775f6-ef61-11e6-9973-5297c04d0733
Master_Info_File: /mydata/data/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)四、主从故障切换
1、确保所有主从数据库都开启二进制日志
mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin | ON |
+---------------+-------+
1 row in set (0.01 sec)2、确保切换时数据时从库都是最新先把主库node01设为只读：set global read_only=1;并且刷新一下主库log-bin日志
mysql> show variables like 'read_only';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| read_only | ON |
+---------------+-------+
1 row in set (0.00 sec)
mysql> flush logs;
Query OK, 0 rows affected (0.02 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 | 154 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)注意：这里的file已经是mysql-bin.000002不是mysql-bin.000001了，Position号是154，不是上面的449了！！！！！
3、确认从库node02，node03的file和pos是否与主库一致。
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.70
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002 #注意这里与主库是否一致
Read_Master_Log_Pos: 154 #注意这里与主库是否一致
Relay_Log_File: relay-bin.000004
Relay_Log_Pos: 367
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes4、以上确认主库node01没有数据更新后，提升node02(192.168.2.71)为主库，node01变为从库
1)node02暂停从库(注意这里也可以暂停node03从库SLAVE，让它依然同步node01)
mysql> STOP SLAVE;
Query OK, 0 rows affected (0.01 sec)2)更改node02为主库master
mysql> RESET MASTER;
Query OK, 0 rows affected (0.01 sec)
mysql> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 154 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)3)关闭新主库node02的只读属性，并创建一个test01数据库(为后面新链接的从库node01和node03是否正常同步)
mysql> SET GLOBAL read_only=0;
Query OK, 0 rows affected (0.00 sec)
mysql> CREATE DATABASE test01;
Query OK, 1 row affected (0.00 sec)这时新主库的Position为以下:
mysql> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 319 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)4)设置node01(原主库)身份为slave,并且更改链接新主库node02信息(注:MASTER_LOG_POS这时应该是老的154，不是创建新test01库后的319)，并启动SLAVE
mysql> RESET SLAVE;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_HOST='192.168.2.71',MASTER_USER='repl', MASTER_PASSWORD='111111',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=154;
Query OK, 0 rows affected, 2 warnings (0.02 sec)
mysql> START SLAVE;
mysql> show slave status\G; #查看从库状态
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.71
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 319
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 485
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
…………
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| apps |
| mysql |
| performance_schema |
| sys |
| test01 | #test01数据也已经过来了
+--------------------+
6 rows in set (0.00 sec)注意:这时查看node03从库，Master_Host依然是node01(192.168.2.70)，但测试验证的数据库test01也依然同步过来了，如果需要更改链接新主库node02，详见下面操作！！
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.70
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 319 #与新主库node02的Position号也保持一致
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
…………
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| apps |
| mysql |
| performance_schema |
| sys |
| test01 | #新创建的test01库也同步过来
+--------------------+
6 rows in set (0.00 sec)**********注意:修改node03从库SLAVE身份，链接新主库node02的信息(注:MASTER_LOG_POS也依然老的154)，修改并重新启动SLAVE*********
mysql> CHANGE MASTER TO MASTER_HOST='192.168.2.71',MASTER_USER='repl', MASTER_PASSWORD='111111',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=154;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> START SLAVE;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.71
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 319 #与新主库node02的Position号也保持一致
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
…………
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| apps |
| mysql |
| performance_schema |
| sys |
| test01 | #新创建的test01库也同步过来
+--------------------+
6 rows in set (0.00 sec)5、再次验证数据，在node02(192.168.2.71)新主库的apps库apps表中，再插入一条新记录，查看是否同步至其他从库
node02主库上执行以下命令:
mysql> USE apps;
Database changed
mysql> INSERT INTO apps (app_name,url,country) VALUES ('XINLANG','http://www.sina.com.cn','CN');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM apps;
+----+------------+-------------------------+---------+
| id | app_name | url | country |
+----+------------+-------------------------+---------+
| 1 | QQ APP | http://im.qq.com/ | CN |
| 2 | 微博 APP | http://weibo.com/ | CN |
| 3 | 淘宝 APP | https://www.taobao.com/ | CN |
| 4 | BAIDU | http://www.baidu.com | CN |
| 5 | XINLANG | http://www.sina.com.cn | CN |
+----+------------+-------------------------+---------+
5 rows in set (0.00 sec)查看从库node01、node03节点，apps表是否也成功插入数据，得到如下结果:
mysql> SELECT * FROM apps;
+----+------------+-------------------------+---------+
| id | app_name | url | country |
+----+------------+-------------------------+---------+
| 1 | QQ APP | http://im.qq.com/ | CN |
| 2 | 微博 APP | http://weibo.com/ | CN |
| 3 | 淘宝 APP | https://www.taobao.com/ | CN |
| 4 | BAIDU | http://www.baidu.com | CN |
| 5 | XINLANG | http://www.sina.com.cn | CN |
+----+------------+-------------------------+---------+
5 rows in set (0.00 sec)对于上文关于实战演示MySQL 5.7.17实现主从复制，大家觉得是自己想要的吗？如果想要了解更多相关，可以继续关注我们的行业资讯板块。
