MySQL 搭建主从数据库

作者: 囿于昼夜 | 来源:发表于2016-12-22 00:05 被阅读482次

使用 MySQL 版本：5.7
系统环境：CentOS 6.5

修改主服务器（master）配置：

$ vim /etc/my.cnf

# 启用二进制日志
log-bin=mysql-bin
# 服务器唯一ID
server-id=111

修改从服务器（slave）配置：

$ vim /etc/my.cnf

# 启用二进制日志，可不配
log-bin=mysql-bin
# 服务器唯一ID
server-id=112

重启两个 MySQL 服务

service mysqld restart;

在主库建一个专用来备份的 MySQL 账户

mysql> grant replication slave,reload,super on *.* 
     > to 'backup'@'192.168.1.50' identified by 'password';
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

backup：账号名
password：密码
192.168.1.50：从库IP地址

记录主库状态

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      622 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

修改从库配置

mysql> change master to master_host='192.168.1.111',master_user='backup',
    -> master_password='1029384756',master_log_file='mysql-bin.000001',
    -> master_log_pos=622;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

主库状态中的 File 对应 master_log_file；
主库状态中的 Position 对应 master_log_pos。

问题

在从库执行show slave status\G;得出结果如下：

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Connecting to master
                  Master_Host: 192.168.1.111
                  Master_User: backup
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 622
               Relay_Log_File: localhost-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Connecting
            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: 622
              Relay_Log_Space: 154
              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: 1045
                Last_IO_Error: error connecting to master 'backup@192.168.1.111:3306' - retry-time: 60  retries: 1
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 0
                  Master_UUID: 
             Master_Info_File: /var/lib/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: 161221 22:56:48
     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)

后检查发现原因是之前在主库中设置从库IP地址时设错了。

于是去主库修改备份账户的IP地址：

mysql> update user set host='192.168.1.112' where user='backup';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

再次查询从库状态：

*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.111
                  Master_User: backup
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 1508
               Relay_Log_File: localhost-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 1032
                   Last_Error: Could not execute Update_rows event on table mysql.user; Can't find record in 'user', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log mysql-bin.000001, end_log_pos 1277
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 622
              Relay_Log_Space: 1417
              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: 1032
               Last_SQL_Error: Could not execute Update_rows event on table mysql.user; Can't find record in 'user', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log mysql-bin.000001, end_log_pos 1277
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 111
                  Master_UUID: 37503273-c521-11e6-90f8-000c29012e9f
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: 
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 161221 23:00:48
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 
                Auto_Position: 0
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version:

初步判断问题是由于之前在主库执行的 update 语句，导致主从库数据不一致，使得数据无法同步。
因此在从库中执行了同样的 update 语句，依然报错。
分析可能是由于 update 语句的执行，主库的日志偏移点发生了变化，使得从库无法同步数据。因此笔者做了如下操作：

# 主库：
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |     1508 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

# 从库：
mysql> stop slave IO_THREAD;
Query OK, 0 rows affected (0.00 sec)

mysql> change master to master_host='192.168.1.111',master_user='backup',
    -> master_password='123',master_log_file='mysql-bin.000001', master_log_pos=1508;
Query OK, 0 rows affected, 2 warnings (0.01 sec)

mysql> start slave io_thread;
Query OK, 0 rows affected (0.01 sec)

# 重启从库的 MySQL 服务
$ service mysqld restart

然后查询从库状态：

*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.111
                  Master_User: backup
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 1508
               Relay_Log_File: localhost-relay-bin.000004
                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: 1508
              Relay_Log_Space: 531
              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: 111
                  Master_UUID: 37503273-c521-11e6-90f8-000c29012e9f
             Master_Info_File: /var/lib/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:

Slave_IO_Running: Yes
Slave_SQL_Running: Yes
成功！

测试一下效果：

# 在主库新增一个 database
mysql> create database mytest1221;
Query OK, 1 row affected (0.02 sec)

# 在从库查询 database
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| mytest1221         |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

MySQL 搭建主从数据库

修改主服务器（master）配置：

修改从服务器（slave）配置：

重启两个 MySQL 服务

在主库建一个专用来备份的 MySQL 账户

记录主库状态

修改从库配置

问题

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