突然收到MySQL报警,从库的数据库挂了,一直在不停的重启,打开错误日志,发现有张表坏了。innodb表损坏不能通过repair table 等修复myisam的命令操作。现在记录下解决过程,下次遇到就不会这么手忙脚乱了。
处理过程:
一遇到报警之后,直接打开错误日志,里面的信息:
InnoDB: Database page corruption on disk or a failedInnoDB: file read of page 30506.InnoDB: You may have to recover from a backup.130509 20:33:48 InnoDB: Page dump in ascii and hex (16384 bytes):##很多十六进制的代码…………InnoDB: End of page dump130509 20:37:34 InnoDB: Page checksum 1958578898, prior-to-4.0.14-form checksum 3765017239InnoDB: stored checksum 3904709694, prior-to-4.0.14-form stored checksum 3765017239InnoDB: Page lsn 5 614270220, low 4 bytes of lsn at page end 614270220InnoDB: Page number (if stored to page already) 30506,InnoDB: space id (if created with >= MySQL-4.1.1 and stored already) 19InnoDB: Page may be an index page where index id is 54InnoDB: (index "PRIMARY" of table "maitem"."email_status")InnoDB: Database page corruption on disk or a failedInnoDB: file read of page 30506.InnoDB: You may have to recover from a backup.InnoDB: It is also possible that your operatingInnoDB: system has corrupted its own file cacheInnoDB: and rebooting your computer removes theInnoDB: error.InnoDB: If the corrupt page is an index pageInnoDB: you can also try to fix the corruptionInnoDB: by dumping, dropping, and reimportingInnoDB: the corrupt table. You can use CHECKInnoDB: TABLE to scan your table for corruption.InnoDB: See also http://dev.mysql.com/doc/refman/5.5/en/forcing-innodb-recovery.htmlInnoDB: about forcing recovery.InnoDB: A new raw disk partition was initialized orInnoDB: innodb_force_recovery is on: we do not allowInnoDB: database modifications by the user. Shut downInnoDB: mysqld and edit my.cnf so that newraw is replacedInnoDB: with raw, and innodb_force_... is removed.130509 20:39:35 [Warning] Invalid (old?) table or database name '#sql2-19c4-5'
从错误日志里面很清楚的知道哪里出现了问题,该怎么处理。这时候数据库隔几s就重启,所以差不多可以说你是访问不了数据库的。所以马上想到要修复innodb表了。
以前在Performance的blog上看过类似文章。
当时想到的是在修复之前保证数据库正常,不是这么异常的无休止的重启。所以就修改了配置文件的一个参数:innodb_force_recovery
innodb_force_recovery影响整个InnoDB存储引擎的恢复状况。默认为0,表示当需要恢复时执行所有的innodb_force_recovery可以设置为1-6,大的数字包含前面所有数字的影响。当设置参数值大于0后,可以对表进行select,create,drop操作,但insert,update或者delete这类操作是不允许的。1(SRV_FORCE_IGNORE_CORRUPT):忽略检查到的corrupt页。2(SRV_FORCE_NO_BACKGROUND):阻止主线程的运行,如主线程需要执行full purge操作,会导致crash。3(SRV_FORCE_NO_TRX_UNDO):不执行事务回滚操作。4(SRV_FORCE_NO_IBUF_MERGE):不执行插入缓冲的合并操作。5(SRV_FORCE_NO_UNDO_LOG_SCAN):不查看重做日志,InnoDB存储引擎会将未提交的事务视为已提交。6(SRV_FORCE_NO_LOG_REDO):不执行前滚的操作。
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