The purpose of this page is to show how databases replication problems were solved. Please contribute when you fix a MySQL replication problem (add a header <date>/<time>: <Problem>). If you fix something which is similar to an existing entry, just add an entry something like 'Fixed problem as in <entry reference>'. When we will have a lot of problems, I (SC) will try to reorganize them by categories.

20110307/0830: Nebulous Replication Error

• Logged onto ippdb02
• Started mysql client as root
• 'SHOW SLAVE STATUS\G' shows the following error:

  Error 'Table 'nebulous.mountedvol' doesn't exist' on query. 
  Default database: 'nebulous'. 
  Query: 'REPLACE INTO mountedvol SELECT vol_id,name,host,path,allocate,available,xattr,mountpoint, 
         '10651598144', '8973230080',note FROM volume WHERE mountpoint = '/data/ipp004.0''
  

• But, if I check the contents of the database, I can see nebulous.mountedvol exists! It seems that the replicated nebulous didn't pass the optimization of last week.
• I'm setting up a new replicated server.

20101116/1659: gpc1 Replication Error

• Logged onto ipp001
• Started mysql client as root
• 'SHOW SLAVE STATUS\G' shows error similar to 20101104/1429: gpc1 Replication Error
• Same solution was applied (Statement skipped)

20101104/1429: gpc1 Replication Error

Problem detected through czartool

• Logged onto ipp001
• Started mysql client as root
• 'SHOW SLAVE STATUS\G' showed (shortened)

            Slave_SQL_Running: No
                   Last_Errno: 1062
                   Last_Error: Error 'Duplicate entry '23' for key 1' on query. Default database: 'ippadmin'. 
                               Query: 'INSERT into cookies (username, cookie) values ('psobs', '99497')'
  

• Local non-replicated database involved... Statement skipped (in MySQL client):

    STOP SLAVE;
    SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1; 
    START SLAVE;
  

  on one line:

    STOP SLAVE; SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1; START SLAVE;
  

• Then 'SHOW SLAVE STATUS\G' showed (shortened)

            Slave_SQL_Running: Yes
                   Last_Errno: 0
                   Last_Error: 
  

• Czartool didn't show any problem after the fix