Identification

Chercher dans les logs la cause de l'arrêt de la réplication :

grep mysql /var/log/syslog 


server1:/home/admin# grep mysql /var/log/syslog
May 29 09:56:08 http2 mysqld[1380]: 080529 9:56:08 [ERROR] Slave: Error 'Table 'mydb.taggregate_temp_1212047760' doesn't exist' on query. Default database: 'mydb'. Query: 'UPDATE thread AS thread,taggregate_temp_1212047760 AS aggregate
May 29 09:56:08 http2 mysqld[1380]: ^ISET thread.views = thread.views + aggregate.views
May 29 09:56:08 http2 mysqld[1380]: ^IWHERE thread.threadid = aggregate.threadid', Error_code: 1146
May 29 09:56:08 http2 mysqld[1380]: 080529 9:56:08 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'mysql-bin.001079' position 203015142
server1:/home/admin#

On voir ici à quelle position la réplication à stoppé.

On peut aussi vérifier cela directement avec mysql

mysql -u root -p
mysql> SHOW SLAVE STATUS \G



*************************** 1. row ***************************

            Slave_IO_State: Waiting for master to send event
               Master_Host: 1.2.3.4
               Master_User: slave_user
               Master_Port: 3306
             Connect_Retry: 60
           Master_Log_File: mysql-bin.001079
       Read_Master_Log_Pos: 269214454
            Relay_Log_File: slave-relay.000130
             Relay_Log_Pos: 100125935
     Relay_Master_Log_File: mysql-bin.001079
          Slave_IO_Running: Yes
         Slave_SQL_Running: No
           Replicate_Do_DB: mydb
       Replicate_Ignore_DB:
        Replicate_Do_Table:
    Replicate_Ignore_Table:
   Replicate_Wild_Do_Table:

Replicate_Wild_Ignore_Table:

                Last_Errno: 1146
                Last_Error: Error 'Table 'mydb.taggregate_temp_1212047760' doesn't exist' on query. Default database: 'mydb'.

Query: 'UPDATE thread AS thread,taggregate_temp_1212047760 AS aggregate

       SET thread.views = thread.views + aggregate.views
       WHERE thread.threadid = aggregate.threadid'
              Skip_Counter: 0
       Exec_Master_Log_Pos: 203015142
           Relay_Log_Space: 166325247
           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

1 row in set (0.00 sec)

on voir ici qu'une requête n'est pas passé. Pour réparere la réplication, nous allons forcer le saut de cette requête.

Réparation

Arrêt du slave

mysql> STOP SLAVE;

Indiquer le nombre de reqûetes dont on va ignorer la réplication (ici 1, mais on pourrait en ignorer 2, 3, ... 100)

mysql> SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1;

Relancer le slave :

mysql> START SLAVE;
mysql> SHOW SLAVE STATUS \G 


mysql> SHOW SLAVE STATUS \G
*************************** 1. row ***************************
             Slave_IO_State: Waiting for master to send event
                Master_Host: 1.2.3.4
                Master_User: slave_user
                Master_Port: 3306
              Connect_Retry: 60
            Master_Log_File: mysql-bin.001079
        Read_Master_Log_Pos: 447560366
             Relay_Log_File: slave-relay.000130
              Relay_Log_Pos: 225644062
      Relay_Master_Log_File: mysql-bin.001079
           Slave_IO_Running: Yes
          Slave_SQL_Running: Yes
            Replicate_Do_DB: mydb
        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: 447560366
            Relay_Log_Space: 225644062
            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
1 row in set (0.00 sec)

Nous constatons que Slave_IO_Running and Slave_SQL_Running sont bien a YES maintenant.