一、问题原因及报错误信息
由于MySQL主库意外重启，导致从库无法同步报错如下：
登录从库查看主从同步的错误信息
[root@192-168-7-101 mysql]# vim mysqld-error.log 2018-12-11 12:57:35 1788 [ERROR] Error reading packet from server: Client requested master to start replication from position > file size; the first event 'master-bin.002295' at 1021866995, the last event read from './master-bin.002295' at 4, the last byte read from './master-bin.002295' at 4. (server_errno=1236) 2018-12-11 12:57:35 1788 [ERROR] Slave I/O: Got fatal error 1236 from master when reading data from binary log: 'Client requested master to start replication from position > file size; the first event 'master-bin.002295' at 1021866995, the last event read from './master-bin.002295' at 4, the last byte read from './master-bin.002295' at 4.', Error_code: 1236
[root@192-168-7-101 mysql]# mysql -u root -p
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 192.168.3.230
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: master-bin.002295
Read_Master_Log_Pos: 1021866995
Relay_Log_File: 192-168-3-236-relay-bin.000001
Relay_Log_Pos: 4
Relay_Master_Log_File: master-bin.002295
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: 1021866995
Relay_Log_Space: 120
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: 1236
Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Client requested master to start replication from position > file size; the first event 'master-bin.002295' at 1021866995, the last event read from './master-bin.002295' at 4, the last byte read from './master-bin.002295' at 4.'
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_UUID: f7c24af7-a54a-11e6-88b4-525400169c04
Master_Info_File: /Data/work/local/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: 181211 12:57:35
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)
二、解决方法
1. 先登录到MySQL主库，搜索后并未找到position的位置
[root@192-168-7-100 mysql]# mysqlbinlog --no-defaults --start-position=1021866995 master-bin.002295 /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/; /*!40019 SET @@session.max_insert_delayed_threads=0*/; /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/; DELIMITER /*!*/; # at 4 #181210 22:41:27 server id 1 end_log_pos 120 CRC32 0x1fe77f51 Start: binlog v 4, server v 5.6.30-log created 181210 22:41:27 BINLOG ' F3sOXA8BAAAAdAAAAHgAAAAAAAQANS42LjMwLWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAXAAEGggAAAAICAgCAAAACgoKGRkAAVF/ 5x8= '/*!*/; DELIMITER ; # End of log file ROLLBACK /* added by mysqlbinlog */; /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/; /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
2. 解析binlog日志文件，找到离1021866995最近的position最近的位置102186424
[root@192-168-7-100 mysql]# mysqlbinlog --no-defaults master-bin.002295 >/root/test.sql
[root@192-168-7-100 mysql]# vim /root/test.sql # at 102186284 #181211 0:05:07 server id 1 end_log_pos 102186315 CRC32 0xd5613884 Xid = 1912388 COMMIT/*!*/; # at 102186315 #181211 0:05:07 server id 1 end_log_pos 102186392 CRC32 0x2b89095e Query thread_id=13545 exec_time=1 error_code=0 SET TIMESTAMP=1544457907/*!*/; BEGIN /*!*/; # at 102186392 # at 102186424 3.登录从库，重新指定主从的同步位置
[root@192-168-7-101 mysql]# mysql -u root -p mysql> stop slave; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> change master to master_log_file='master-bin.002295',master_log_pos=102186424; Query OK, 0 rows affected (0.16 sec) mysql> start slave; Query OK, 0 rows affected (0.03 sec) mysql> show slave status \G *************************** 1. row *************************** Slave_IO_State: Queueing master event to the relay log Master_Host: 192.168.3.230 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.002295 Read_Master_Log_Pos: 155577520 Relay_Log_File: 192-168-7.100-relay-bin.000002 Relay_Log_Pos: 498191 Relay_Master_Log_File: master-bin.002295 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: 102684331 Relay_Log_Space: 53391561 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: 46929 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: f7c24af7-a54a-11e6-88b4-525400169c04 Master_Info_File: /Data/work/local/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: updating 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)