MySQL主從故障修復

測試庫：
192.168.1.2 主
192.168.1.3 從

192.168.1.4 主 4又是2的從庫
192.168.1.5 從

有人修改了192.168.1.2和192.168.1.3的資料庫引數後，重啟資料庫。
忘記了192.168.1.4又是192.168.1.2的從庫，導致192.168.1.2和192.168.1.4的主從斷掉。
並且在192.168.1.2上建立了新庫還原資料刪除等操作，導致192.168.1.4提示錯誤。

模擬如下：
透過從庫檢視主從狀態：
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.33.243
Master_User: master
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000006
Read_Master_Log_Pos: 303
Relay_Log_File: relay-log.000005
Relay_Log_Pos: 340
Relay_Master_Log_File: mysql-bin.000006
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB: test
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1049
Last_Error: Error 'Unknown database 'sakila'' on query. Default database: 'sakila'. Query: 'create table sakila (id int,name varchar(2))'
Skip_Counter: 0
Exec_Master_Log_Pos: 194
Relay_Log_Space: 745
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: 1049
Last_SQL_Error: Error 'Unknown database 'sakila'' on query. Default database: 'sakila'. Query: 'create table sakila (id int,name varchar(2))'
Replicate_Ignore_Server_Ids:
Master_Server_Id: 360360
1 row in set (0.00 sec)

記錄下二進位制日誌的和點的位置：
Relay_Master_Log_File: mysql-bin.000006
Exec_Master_Log_Pos: 194

停掉從庫的slave
mysql> stop slave;
Query OK, 0 rows affected (0.01 sec)

並在主庫刪除掉新建的庫
mysql> drop database sakila;
Query OK, 1 row affected (0.04 sec)

重新進行主從複製
mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000006 | 388 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql> change master to master_host='192.168.1.2',master_port=3306,master_user='master',master_password='123456',master_log_file='mysql-bin.000006',master_log_pos=388;
Query OK, 0 rows affected (0.01 sec)

mysql> start slave ;
Query OK, 0 rows affected (0.00 sec)

檢視主從狀態還提示原來的錯誤，使用sql_slave_skip_counter引數
mysql> show variables like '%skip%';
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| skip_external_locking | ON |
| skip_name_resolve | ON |
| skip_networking | OFF |
| skip_show_database | OFF |
| slave_skip_errors | OFF |
| sql_slave_skip_counter | 0 |
+------------------------+-------+
6 rows in set (0.00 sec)

預設為0

mysql> set global sql_slave_skip_counter = 1;

mysql> start slave;

還提示錯誤，繼續

mysql> set global sql_slave_skip_counter = 1;

mysql> start slave;

mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.2
Master_User: master
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000006
Read_Master_Log_Pos: 388
Relay_Log_File: relay-log.000002
Relay_Log_Pos: 253
Relay_Master_Log_File: mysql-bin.000006
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: test
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: 388
Relay_Log_Space: 403
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: 360360

最後在192.168.1.2上重新建庫並還原資料

MySQL主從修復

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