我的 CentOS 服务器上的 MySQL 守护进程不断崩溃，我从 /var/logs/mysqld 获取了日志，但我仍然不确定如何修复它：
121114 16:22:56 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
121114 21:55:11 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
121114 21:55:11 [Note] Plugin 'FEDERATED' is disabled.
121114 21:55:11 InnoDB: The InnoDB memory heap is disabled
121114 21:55:11 InnoDB: Mutexes and rw_locks
use GCC atomic builtins
121114 21:55:11 InnoDB: Compressed tables use zlib 1.2.3
121114 21:55:11 InnoDB: Using Linux native AIO
121114 21:55:11 InnoDB: Initializing buffer pool, size = 128.0M
121114 21:55:11 InnoDB: Completed initialization of buffer pool
121114 21:55:11 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
121114 21:55:11 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
121114 21:55:12 InnoDB: Waiting for the background threads to start
121114 21:55:13 InnoDB: 1.1.6 started; log sequence number 77177262
121114 21:55:13 [Note] Event Scheduler: Loaded 0 events
121114 21:55:13 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.5.12' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL) by Remi
121115 00:19:44 mysqld_safe Number of processes running now: 0
121115 00:19:44 mysqld_safe mysqld restarted
121115 0:19:47 [Note] Plugin 'FEDERATED' is disabled.
121115 0:19:47 InnoDB: The InnoDB memory heap is disabled
121115 0:19:47 InnoDB: Mutexes and rw_locks use GCC atomic builtins
121115 0:19:47 InnoDB: Compressed tables use zlib 1.2.3
121115 0:19:47 InnoDB: Using Linux native AIO
121115 0:19:47 InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137363456 bytes) failed; errno 12
121115 0:19:47 InnoDB: Completed initialization of buffer pool
121115 0:19:47 InnoDB: Fatal error: cannot allocate memory for the buffer pool
121115 0:19:47 [ERROR] Plugin 'InnoDB' init function returned error.
121115 0:19:47 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
121115 0:19:47 [ERROR] Unknown/unsupported storage engine: InnoDB
121115 0:19:47 [ERROR] Aborting
编辑#1
total used free shared buffers cached
Mem: 496 370 126 0 24 110
-/+ buffers/cache: 234 261
Swap: 1023 9 1014
编辑#2
另外，我的 mysql 中最大的表是 20MB，所以使用的内存应该相当适中。
SELECT CONCAT(table_schema, '.', table_name),
CONCAT(ROUND(table_rows / 1000000, 2), 'M') rows,
CONCAT(ROUND(data_length / ( 1024 * 1024 * 1024 ), 2), 'G') DATA,
CONCAT(ROUND(index_length / ( 1024 * 1024 * 1024 ), 2), 'G') idx,
CONCAT(ROUND(( data_length + index_length ) / ( 1024 * 1024 * 1024 ), 2), 'G') total_size,
ROUND(index_length / data_length, 2) idxfrac
FROM information_schema.TABLES
ORDER BY data_length + index_length DESC
LIMIT 10;
答案1
InnoDB: Fatal error: cannot allocate memory for the buffer pool
从外观上看，您的服务器无法为 innodb 分配足够的内存。
写入free -m以查看您必须分配多少内存。查看您的/etc/my.cnf并查看innodb_buffer_pool_size所做的更改。
如果您愿意，您可以启动不使用 innodb 的 mysql，有些人这样做是为了降低内存占用。mysqld --skip-innodb --default-storage-engine=myisam