同步问题实在解决不了时,以主库为准。
mysqldump -uroot -p --single-transaction --master-data=2 --no-autocommit -A >alldatas.sql
将从库上的数据库清空,并还原为普通的数据库,(删除master.info relay-log.info relay-bin.index)
一般情况下reset slave就可以了,如果reset slave也不行,那就需要reset master了。
mysql> reset master;mysql> show master status\G
如果reset master发生在mysqldump之后,则需要通过show master status\G;来确定从库需要更新的位置,这时如果没有在停机状态下是不准确的。如果需要reset master,最好是在reset之后再dump一份新的数据文件出来。
mysql> stop slave;mysql> reset slave;mysql> show slave status\G
这种情况需要注意上面提到的reset master与dump的先后顺序。
mysql> show master status\G;*************************** 1. row *************************** File: bin.000002 Position: 77530910 Binlog_Do_DB: Binlog_Ignore_DB: Executed_Gtid_Set: 1 row in set (0.00 sec)
这个在不停机状态下position和file都是在变化状态的,因为会有新的插入进来,需要注意。
mysql> CHANGE MASTER TO -> MASTER_HOST='192.168.1.99', -> MASTER_USER='test99', -> MASTER_PASSWORD='aA&12345', -> MASTER_LOG_FILE='bin.000002', -> MASTER_LOG_POS= 77530910;
mysql> start slave;Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;*************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.1.163 Master_User: test123 Master_Port: 3306 Connect_Retry: 60 Master_Log_File: bin.000002 Read_Master_Log_Pos: 77530910 Relay_Log_File: mysql-relay-bin.000002 Relay_Log_Pos: 314 Relay_Master_Log_File: bin.000002 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: 77530910 Relay_Log_Space: 521 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: 0Master_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: 163 Master_UUID: ec5e1ee1-f6e2-11e8-949d-005033ee2217 Master_Info_File: /work1/data/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: 1 row in set (0.01 sec)
执行成功之后主从数据不同步的问题就可以修复了。