MariaDB完成C轮2700万美元投资 阿里巴巴领投

11月2日,知名开源数据库公司MariaDB 宣布完成由阿里巴巴领投的C轮2700万美元的融资。融资完成后,MariaDB社区将具备更强的实力参与数据库日益激烈的竞争。MariaDB是全球知名的开源数据库,总部位于芬兰赫尔辛基,全球共计有 1200万用户,包括 booking.com、惠普、维珍移动、维基百科等,提供混合云、公有云和私有云等形式的部署。 继续阅读MariaDB完成C轮2700万美元投资 阿里巴巴领投

Plugin ‘FEEDBACK’ is disabled

MySQL低版本升级高版本一般会出现Plugin 'FEEDBACK' is disabled这个错误,通常还伴随The InnoDB memory heap is disabled问题一起出现。

如果是The memory heap is disabled错误可以在[mysqld]下方增加"_use_sys_malloc = 1",即使用系统自动分配内存。而Plugin 'FEEDBACK' is disabled只需要在[mysqld]下方增加“feedback=ON”即可开启。

参考MariaDB提供的文档:Feedback Plugin

Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler

mysql迁移至mariadb的时候出现:

Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler

解决办法:

停止MySQL,备份

移除旧mysql,初始化mysql

继续阅读Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler

InnoDB: If you are attempting downgrade from MySQL 5.7.9 or later

: If you are attempting downgrade from 5.7.9 or later

这是一个版本问题,之前安装过mysql 5.7,再回到mariadb 5.5出现的问题。之后我搜了下网上很多人有这个问题。错误全文:

160916 17:03:21 mysqld_safe Starting mysqld daemon with databases from /var/lib/
2016-09-16 17:03:22 139911928530976 [Note] /usr/sbin/mysqld (mysqld 10.1.17-) starting as process 16541 ...
2016-09-16 17:03:22 139911928530976 [Note] : Using mutexes to ref count buffer pool pages
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: The InnoDB memory heap is disabled
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Compressed tables use zlib 1.2.3
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Using Linux native AIO
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Using SSE crc32 instructions
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Completed initialization of buffer pool
2016-09-16 17:03:22 139911928530976 [Note] InnoDB: Highest supported file format is Barracuda.
InnoDB: No valid checkpoint found.
InnoDB: If you are attempting downgrade from MySQL 5.7.9 or later,
InnoDB: please refer to http://dev.mysql.com/doc/refman/5.6/en/upgrading-downgrading.html
InnoDB: If this error appears when you are creating an InnoDB database,
InnoDB: the problem may be that during an earlier attempt you managed
InnoDB: to create the InnoDB data files, but log file creation failed.
InnoDB: If that is the case, please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.6/en/error-creating-innodb.html
2016-09-16 17:03:22 139911928530976 [ERROR] Plugin 'InnoDB' init function returned error.
2016-09-16 17:03:22 139911928530976 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2016-09-16 17:03:22 139911928530976 [Note] Plugin 'FEEDBACK' is disabled.
2016-09-16 17:03:22 139911928530976 [ERROR] Unknown/unsupported storage engine: InnoDB
2016-09-16 17:03:22 139911928530976 [ERROR] Aborting

160916 17:03:22 mysqld_safe mysqld from pid file /var/lib/mysql/iZ236priv51Z.pid ended

继续阅读InnoDB: If you are attempting downgrade from MySQL 5.7.9 or later

MySQL 5.7或者MariaDB经常关闭的解决办法

5.7、MariaDB经常关闭,如果配置没有错,那么大多原因是由于服务器内存不够用,特别是很多云服务器或者VPS都是512MB的内容。针对小内存的服务器可以将数据库的消耗调小即可。

首先备份 /etc/my.cnf

在my.cnf中的[mysqld]下方插入

重启mysql即可。