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Mysql 5.6主從同步失敗的解決辦法
明天就五一了, 結果數據庫掛了~
原因還沒搞清楚,不過主從同步也隨之出問題了~
按照常理跳過問題點的處理方式已經沒辦法解決了, 所以這裡提供我的暴力處理方式
首先登陸主數據庫,鎖表、重置位置即文件參數(都說了是暴力)
FLUSH TABLES WITH READ LOCK;
reset master;
用各種辦法備份你的所有待同步的表,比如到處語句啊, 還有直接把數據庫文件復制到從服務器上呀(僅限MyISAM), 總之方法隨便你
其次登陸從數據庫,重置參數
reset master;
stop slave;
reset slave;
最後將主庫的數據與從庫數據保持一致, 你可以采取備份主庫導入從庫,或者直接覆蓋(僅限MyISAM)
然後重啟從數據庫
service mysql restart;
接著直接解鎖主數據庫
unlock tables;
然後查看狀態, 基本上問題就解決了, 但還是不推薦大家在生產環境中這麼高
從:
show slave status\G
主:
show master status\G
mysql主從復制跳過錯誤
mysql主從復制，經常會遇到錯誤而導致slave端復制中斷，這個時候一般就需要人工干預，跳過錯誤才能繼續
跳過錯誤有兩種方式：
1.跳過指定數量的事務：
mysql>slave stop;
mysql>SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1 #跳過一個事務
mysql>slave start
2.修改mysql的配置文件，通過slave_skip_errors參數來跳所有錯誤或指定類型的錯誤
vi /etc/my.cnf
[mysqld]
#slave-skip-errors=1062,1053,1146 #跳過指定error no類型的錯誤
#slave-skip-errors=all #跳過所有錯誤
例：下面模擬一個錯誤場景
環境（一個已經配置好的主從復制環境）
master數據庫IP：192.168.247.128
slave數據庫IP：192.168.247.130
mysql版本：5.6.14
binlog-do-db = mydb
在master上執行以下語句：
mysql>use mysql;
mysql>create table t1 (id int);
mysql>use mydb;
mysql>insert into mysql.t1 select 1;
在slave上查看復制狀態
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.247.128
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000017
Read_Master_Log_Pos: 2341
Relay_Log_File: DBtest1-relay-bin.000011
Relay_Log_Pos: 494
Relay_Master_Log_File: mysql-bin.000017
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: 1146
Last_Error: Error 'Table 'mysql.t1' doesn't exist' on query. Default database: 'mydb'. Query: 'insert into mysql.t1 select 1'
Skip_Counter: 0
Exec_Master_Log_Pos: 1919
Relay_Log_Space: 1254
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: 1146
Last_SQL_Error: Error 'Table 'mysql.t1' doesn't exist' on query. Default database: 'mydb'. Query: 'insert into mysql.t1 select 1'
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_UUID: f0f7faf6-51a8-11e3-9759-000c29eed3ea
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: 131210 21:37:19
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
由結果可以看到，Read_Master_Log_Pos: 2341，Exec_Master_Log_Pos: 1919 時出錯了Last_SQL_Error: Error 'Table 'mysql.t1' doesn't exist' on query.
因為只對mydb記錄了binlog,當在mydb庫操作其它數據庫的表，但該表在slave上又不存在時就出錯了。
我們可在看看binlog裡的事務內容，這裡一行代表一個事務
mysql> SHOW BINLOG EVENTS in 'mysql-bin.000017' from 1919\G
*************************** 1. row ***************************
Log_name: mysql-bin.000017
Pos: 1919
Event_type: Query
Server_id: 1
End_log_pos: 1999
Info: BEGIN
*************************** 2. row ***************************
Log_name: mysql-bin.000017
Pos: 1999
Event_type: Query
Server_id: 1
End_log_pos: 2103
Info: use `mydb`; insert into mysql.t1 select 1
*************************** 3. row ***************************
Log_name: mysql-bin.000017
Pos: 2103
Event_type: Xid
Server_id: 1
End_log_pos: 2134
Info: COMMIT /* xid=106 */
*************************** 4. row ***************************
Log_name: mysql-bin.000017
Pos: 2134
Event_type: Query
Server_id: 1
End_log_pos: 2213
Info: BEGIN
*************************** 5. row ***************************
Log_name: mysql-bin.000017
Pos: 2213
Event_type: Query
Server_id: 1
End_log_pos: 2310
Info: use `mydb`; insert into t1 select 9
*************************** 6. row ***************************
Log_name: mysql-bin.000017
Pos: 2310
Event_type: Xid
Server_id: 1
End_log_pos: 2341
Info: COMMIT /* xid=107 */
6 rows in set (0.00 sec)
由上面的結果可知，我們需要跳過兩個事務（Pos: 1999 insert,Pos: 2103 commit)
跳過操作：
mysql>slave stop;
mysql>SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 2 跳過一個事務
mysql>slave start
mysql> show slave status\G
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 3
Current database: mydb
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.247.128
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000017
Read_Master_Log_Pos: 3613
Relay_Log_File: DBtest1-relay-bin.000018
Relay_Log_Pos: 283
Relay_Master_Log_File: mysql-bin.000017
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: 3613
Relay_Log_Space: 458
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: 1
Master_UUID: f0f7faf6-51a8-11e3-9759-000c29eed3ea
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 the slave I/O thread to update it
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 (0.01 sec)
復制狀態正常。
