Recently, a MySQL server I manage has shut down abnormally. I find some information in error log Plugin 'FEDERATED' is disabled.
The FEDERATED storage engine is available beginning with MySQL 5.0.3. It is a storage engine that accesses data in tables of remote databases rather than in local tables.
The FEDERATED storage engine is available beginning with MySQL 5.0.3. This storage engine enables data to be accessed from a remote MySQL database on a local server without using replication or cluster technology. When using a FEDERATED table, queries on the local server are automatically executed on the remote (federated) tables. No data is stored on the local tables.
We can find more information about the FEDERATED storage engine from MySQL Official.
# cat /var/log/mysql/error.log 141104 4:53:28 [Note] Plugin 'FEDERATED' is disabled. 141104 4:53:28 InnoDB: The InnoDB memory heap is disabled 141104 4:53:28 InnoDB: Mutexes and rw_locks use GCC atomic builtins
After the time mysqld will be stop, this also is due that the FEDERATED storage engine is disabled.
141105 23:26:16 [Note] /usr/sbin/mysqld: Normal shutdown 141105 23:26:16 [Note] Event Scheduler: Purging the queue. 0 events 141105 23:26:16 InnoDB: Starting shutdown... 141105 23:26:16 InnoDB: Shutdown completed; log sequence number 36647590017 141105 23:26:16 [Warning] Forcing shutdown of 1 plugins 141105 23:26:16 [Note] /usr/sbin/mysqld: Shutdown complete
Use SHOW PLUGINS
command, we can confirm that the FEDERATED storage engine is disabled.
mysql> show plugins -> ; +--------------------------+----------+--------------------+---------+---------+ | Name | Status | Type | Library | License | +--------------------------+----------+--------------------+---------+---------+ | binlog | ACTIVE | STORAGE ENGINE | NULL | GPL | | mysql_native_password | ACTIVE | AUTHENTICATION | NULL | GPL | | mysql_old_password | ACTIVE | AUTHENTICATION | NULL | GPL | | MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | | MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL | | CSV | ACTIVE | STORAGE ENGINE | NULL | GPL | MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | ▽ BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | GPL | | FEDERATED | DISABLED | STORAGE ENGINE | NULL | GPL | | InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL | | INNODB_TRX | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_LOCKS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_LOCK_WAITS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMP | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMP_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMPMEM | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMPMEM_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_BUFFER_PAGE | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_BUFFER_PAGE_LRU | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_BUFFER_POOL_STATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | PERFORMANCE_SCHEMA | ACTIVE | STORAGE ENGINE | NULL | GPL | | ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | GPL | | partition | ACTIVE | STORAGE ENGINE | NULL | GPL | +--------------------------+----------+--------------------+---------+---------+ 23 rows in set (0.00 sec)
Describe the following settings in /etc/mysql/my.cnf
, in [mysqld]
section, will be able to re-enable the FEDERATED storage engine.
federated = 1
After save my.cnf
, restart MySQL service.