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mysql主从搭建切换

发表于：2025-11-07 作者：千家信息网编辑

千家信息网最后更新 2025年11月07日，环境：172.30.249.156 percona5.6.27 主机名：tr-mysql 跑着生产环境的应用的虚拟机192.168.129.153 percona5.6.27 主机名：trcloud-

千家信息网最后更新 2025年11月07日mysql主从搭建切换

环境：
172.30.249.156 percona5.6.27 主机名：tr-mysql 跑着生产环境的应用的虚拟机
192.168.129.153 percona5.6.27 主机名：trcloud-gtt-db 新申请的物理机
工作内容：给生产环境数据库搭建主从架构，并将主库放到新申请的物理机上,连续停机不能超过10分钟
大致流程：搭建主从-->主备切换-->测试结果，因为生产环境数据大概有100多G，考虑到停机时间和效率的问题，恢复备库使用Xtrabackup方式备份恢复，不使用mysqldump和冷备的方式

一：搭建主从

1、创建复制账号

在Master的数据库中建立一个备份帐户：每个slave使用标准的MySQL用户名和密码连接master。进行复制操作的用户会授予REPLICATION SLAVE权限。

命令如下：

mysql> create user 'replicat'@'192.168.129.153' identified by 'passw';
Query OK, 0 rows affected (0.03 sec)
mysql> grant replication slave,super on *.* to 'replicat'@'192.168.129.153';
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
建立一个帐户backup，并且只能允许从10.211.55.5这个地址上来登陆，密码是passw。

2、配置master、slave参数
主库:
打开二进制日志、指定唯一server ID、
[root@localhost data]# vi /etc/my.cnf
……
log-bin=/data/DB/mysql/mysql-bin
server-id=1
…….
备库:
打开二进制日志、指定唯一server ID
[root@localhost mysql]# vi /etc/my.cnf
……
log-bin=/data/DB/mysql/mysql-bin
server-id=2
…….

3、拷贝并恢复备库数据
主库备份：
[root@tr-mysql backup]# xtrabackup --backup --user=root --datadir=/data/DB/mysql/ --target-dir=/data/backup/20160628bak/
........
160628 09:55:17 Executing UNLOCK TABLES
160628 09:55:17 All tables unlocked
160628 09:55:17 Backup created in directory '/data/backup/20160628bak/'
160628 09:55:17 [00] Writing backup-my.cnf
160628 09:55:17 [00] ...done
160628 09:55:18 [00] Writing xtrabackup_info
160628 09:55:18 [00] ...done
xtrabackup: Transaction log of lsn (1696091795) to (1696091805) was copied.
160628 09:55:18 completed OK!
[root@tr-mysql backup]# xtrabackup --prepare --target-dir=/data/backup/20160628bak/ --让备份数据一致
[root@tr-mysql backup]# scp 20160628bak/* root@192.168.129.153:/data/backup/20160628bak/
备库恢复：
[root@trcloud-gtt-db ~]# rsync -avrp /data/backup/20160628bak/ /data/DB/mysql/
........
sent 6426459950 bytes received 259 bytes 197737237.20 bytes/sec
total size is 6425674808 speedup is 1.00
[root@trcloud-gtt-db~ ]# chown -R mysql:mysql /data/DB/mysql

4、主库准备测试数据
mysql> use test;
mysql> create table id(id int(10));
Query OK, 0 rows affected (1.02 sec)
mysql> insert into id values(1);
Query OK, 1 row affected (0.14 sec)

5、设置复制进程
查看master当前binlog文件
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 | 834 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
slave创建复制进程
mysql> change master to master_host='172.30.249.156',
-> master_user='replicat',
-> master_password='passw',
-> master_log_file='mysql-bin.000002',
-> master_log_pos=0;

6、启动slave，查看进程
启动
mysql> start slave;
Query OK, 0 rows affected (0.03 sec)
查看slave进程
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.30.249.156
Master_User: replicat
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 834
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 997
Relay_Master_Log_File: mysql-bin.000002
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: 834
Relay_Log_Space: 1171
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: 7d7ee32c-26cd-11e6-8fe2-fa163ecb3078
Master_Info_File: /data/DB/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
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
1 row in set (0.00 sec)
在这里主要是看:
Slave_IO_Running=Yes
Slave_IO_Running=Yes
Slave_SQL_Running=Yes
slave的I/O和SQL线程都已经开始运行，而且Seconds_Behind_Master不再是NULL。日志的位置增加了，意味着一些事件被获取并执行了。如果你在master上进行修改，你可以在slave上看到各种日志文件的位置的变化，同样，你也可以看到数据库中数据的变化。
查看master进程
mysql> show processlist\G;
........
*************************** 3. row ***************************
Id: 4
User: canal
Host: 172.30.248.95:35966
db: NULL
Command: Binlog Dump
Time: 11821
State: Master has sent all binlog to slave; waiting for binlog to be updated
Info: NULL
Rows_sent: 0
Rows_examined: 0
........
*************************** 5. row ***************************
Id: 12
User: replicat
Host: 192.168.129.153:51948
db: NULL
Command: Binlog Dump
Time: 614
State: Master has sent all binlog to slave; waiting for binlog to be updated
Info: NULL
Rows_sent: 0
Rows_examined: 0

7、测试结果
slave上查看创建的表和数据都有了
mysql> select * from id;
+------+
| id |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
在master上修改数据
mysql> update id set id=2 where id =1;
Query OK, 1 row affected (0.08 sec)
Rows matched: 1 Changed: 1 Warnings: 0
查看slave数据
mysql> select * from id;
+------+
| id |
+------+
| 2 |
+------+
1 row in set (0.00 sec)
测试通过

二：主从切换

1、在从库（新的主服务器）上创建用户
mysql> create user 'replicat'@'172.30.249.156' identified by 'passw';
Query OK, 0 rows affected (0.03 sec)
mysql> grant replication slave,super on *.* to 'replicat'@'172.30.249.156';
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

2、从库（新的主服务器）操作
mysql> STOP SLAVE IO_THREAD;
Query OK, 0 rows affected (0.03 sec)
mysql> SHOW PROCESSLIST;
+----+-----------------+-----------+------+---------+------+-----------------------------------------------------------------------------+------------------+-----------+---------------+
| Id | User | Host | db | Command | Time | State | Info | Rows_sent | Rows_examined |
+----+-----------------+-----------+------+---------+------+-----------------------------------------------------------------------------+------------------+-----------+---------------+
| 1 | event_scheduler | localhost | NULL | Daemon | 2238 | Waiting on empty queue | NULL | 0 | 0 |
| 5 | root | localhost | test | Query | 0 | init | SHOW PROCESSLIST | 0 | 0 |
| 7 | system user | | NULL | Connect | 809 | Slave has read all relay log; waiting for the slave I/O thread to update it | NULL | 0 | 0 |
+----+-----------------+-----------+------+---------+------+-----------------------------------------------------------------------------+------------------+-----------+---------------+
确保状态为：has read all relay log
mysql> show slave status \G；
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 172.30.249.156
Master_User: replicat
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 1523
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 1686
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: No
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: 1523
Relay_Log_Space: 1860
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: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_UUID: 7d7ee32c-26cd-11e6-8fe2-fa163ecb3078
Master_Info_File: /data/DB/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
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

3、从库变主库
mysql> STOP SLAVE;
Query OK, 0 rows affected (0.03 sec)
mysql> RESET MASTER;
Query OK, 0 rows affected (0.12 sec)
mysql> RESET SLAVE;
Query OK, 0 rows affected (0.11 sec)
mysql> show master status \G
*************************** 1. row ***************************
File: mysql-bin.000009
Position: 120
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)

4、主库变从库
mysql> RESET MASTER;
Query OK, 0 rows affected (3.36 sec)
mysql> RESET SLAVE;
Query OK, 0 rows affected (0.00 sec)
设置slave进程
mysql> change master to master_host='192.168.129.153',
-> master_user='replicat',
-> master_password='passw',
-> master_log_file='mysql-bin.000009',
-> master_log_pos=120;
启动slave进程
mysql> start slave;

5、修改参数并重启
将从库变成只读
修改现在的从库参数
read-only =1
innodb_read_only =1
super_read_only =1 #（拥有super权限也无法修改）
重启
[root@tr-mysql mysql]# service mysql restart

6、检查主从是否都正常
主库
SHOW PROCESSLIST;
show master status \G
从库
SHOW PROCESSLIST;
start slave;
show slave status \G

7、测试数据
主库
mysql> update id set id=1 where id=2;
Query OK, 1 row affected (0.02 sec)
Rows matched: 1 Changed: 1 Warnings: 0
从库
mysql> select * from id;
+------+
| id |
+------+
| 1 |
+------+
切换成功

很赞哦！