mysql数据库实现主从复制

服务器准备

主服务器：192.168.93.103
从服务器：192.168.93.102

主服务器操作

修改配置文件

[[email protected] ~]#vim /etc/my.cnf

[mysqld]
server_id=103                               //指定一个服务id,如果不写这里默认为1
log_bin=/data/mysql/bin/mysql-bin           //必须启动二进制日志
binlog_format=row                           //建议使用行row记录日志
innodb_file_per_table
datadir=/var/lib/mysql

创建主从复制用户

MariaDB [(none)]> grant replication slave on *.* to [email protected]‘192.168.93.%‘identified by ‘centos‘;

查看主服务器的二进制日志，记录要复制的位置

[[email protected] ~]#mysql -e ‘show master logs‘;
+------------------+-----------+
| Log_name         | File_size |
+------------------+-----------+
| mysql-bin.000002 |       288 |
| mysql-bin.000003 |       288 |
| mysql-bin.000004 |       442 |
| mysql-bin.000005 |       245 |
+------------------+-----------+

如何解决主从复制一台已存在大量数据的mysql服务器？

问题描述：如果一台mysql主服务器已经运行了一段时间，主服务器的数据量非常大，而主从复制时间会很长，对主服务器压力过大

解决办法：先在主服务器上创建完全备份，还原到从服务器上后，再做主从复制

完全备份数据库

[[email protected] ~]#mysqldump -A --single-transaction -F --master-data=1 > /data/backup/all.sql

查看记录二进制日志中要复制的位置信息

[[email protected] ~]#vim /data/backup/all.sql 

CHANGE MASTER TO MASTER_LOG_FILE=‘mysql-bin.000018‘, MASTER_LOG_POS=245;

在从服务器需要做的操作：
修改配置文件
将主服务器完全备份的数据库文件all.sql拷贝至从服务器

[[email protected] ~]#scp 192.168.93.102:/data/backup/all.sql  /data/backup

修改/data/backup/all.sql文件里完全备份位置语句：
CHANGE MASTER TO MASTER_LOG_FILE=‘mysql-bin.000018‘,MASTER_LOG_POS=245;
修改为：

vim /data/backup/all.sql

CHANGE MASTER TO
MASTER_HOST=‘192.168.93.103‘,
MASTER_USER=‘repluser‘,
MASTER_PASSWORD=‘centos‘,
MASTER_PORT=3306,
MASTER_LOG_FILE=‘mysql-bin.000018‘,
MASTER_LOG_POS=245;

然后导入all.sql文件

[[email protected] ~]# mysql < all.sql

启动主从同步线程

MariaDB [(none)]> start slave;

从服务器操作

修改配置文件

[[email protected] ~]# vim /etc/my.cnf

[mysqld]
server_id=102    //指定从服务器的服务id，不能不写，默认为1，此id不能与其他服务器冲突
read_only=ON        //设置数据库只读

使用有复制权限的用户账号连接至主服务器，配置同步信息

MariaDB [(none)]> CHANGE MASTER TO
MASTER_HOST=‘192.168.93.103‘,  //远程主服务器IP
MASTER_USER=‘repluser‘,             //主从复制的用户名
MASTER_PASSWORD=’centos’,         //密码
MASTER_PORT=3306,                 //端口号
MASTER_LOG_FILE=‘mysql-bin.000017‘,  //要复制的主服务器的二进制文件名
MASTER_LOG_POS=245;           //要开始复制的位置

启动复制线程

MariaDB [(none)]> start  slave;
Query OK, 0 rows affected (0.00 sec)

显示线程列表

MariaDB [(none)]> show processlist;
+----+-------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+------------------+----------+
| Id | User        | Host      | db   | Command | Time   | State                                                                       | Info             | Progress |
+----+-------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+------------------+----------+
|  3 | root        | localhost | NULL | Query   |      0 | NULL                                                                        | show processlist |    0.000 |
|  6 | system user |           | NULL | Connect |    264 | Waiting for master to send event                                            | NULL             |    0.000 |
|  7 | system user |           | NULL | Connect | -27302 | Slave has read all relay log; waiting for the slave I/O thread to update it | NULL             |    0.000 |
+----+-------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+------------------+----------+
3 rows in set (0.00 sec)

显示主服务器的状态信息

MariaDB [(none)]> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.93.103
                  Master_User: repluser
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000017
          Read_Master_Log_Pos: 399
               Relay_Log_File: mariadb-relay-bin.000002
                Relay_Log_Pos: 683
        Relay_Master_Log_File: mysql-bin.000017
             Slave_IO_Running: Yes   //主从复制的线程IO
            Slave_SQL_Running: Yes   //主从复制的线程SQL
              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: 399
              Relay_Log_Space: 979
              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         //主从复制的时间差
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: 103
1 row in set (0.00 sec)

ERROR: No query specified

原文地址：https://blog.51cto.com/14233815/2390068