- 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)
