Mysql Innodb 性能参数设置 https://www.rathishkumar.in/2017/01/how-to-allocate-innodb-buffer-pool-size-in-m

Posted 2020-11-21 bug_x

参考原文：

 https://www.rathishkumar.in/2017/01/how-to-allocate-innodb-buffer-pool-size-in-mysql.html

查看系统cpu,内存，硬盘使用情况

1、 cat /proc/cpuinfo  或者 更直观的查看cpu的型号命令：dmesg |grep -i xeon

查看内存的方法

2、 cat /proc/meminfo  或者 更直观的查看内存的命令：free -m

查看硬盘大小

3、df -h

这里粘贴部分原文：

What is there inside MySQL InnoDB buffer pool?

MySQL InnoDB buffer pool contains the following things inside:

Data caching - InnoDB data pages.
Indices caching - index data.
Buffering data - Dirty pages - data which are modified in memory but not yet flushed (written) to a data disk.
Internal structures - InnoDB buffer pool additionally stores the internal structures such as Adaptive Hash Index, row level locks, etc.

The unit of the above-mentioned objects are calculated as - InnoDB pages. Each InnoDB pages is 16k in size.

 

如何最优设置：

How to deal with this situation?

When we cannot keep an entire database in memory, we should try to keep at least working data set in memory. In most cases, we are not going to process the data of an entire table, so the required data set should be in memory. So it is always better to allocate around 75% - 80% of the total available memory of server machine to innodb_buffer_pool_size.

同时文中给出了其中的一个计算方式：

How much memory should allocate to InnoDB buffer pool?

Recommended InnoDB buffer pool size based on the all InnoDB data and indices with additional 50% memory:


set @idbdataindx = (select sum(data_length+index_length) from information_schema.tables where engine = ‘innodb‘);

set @ibpsG = @idbdataindx * 1.5 / (1024*1024*1024);

select @ibpsG;

 

如何设置：

SHOW VARIABLES LIKE ‘%innodb_buffer_pool_size%‘;
Example:
Online method:
SET GLOBAL innodb_buffer_pool_size = 26843545600;

Offline method:
innodb_buffer_pool = 26G   (需要重启服务器)

 

 

 

 

 

SHOW VARIABLES LIKE ‘%innodb_buffer_pool_size%‘;

Example:

Online method:

SET GLOBAL innodb_buffer_pool_size = 26843545600;

Offline method:

innodb_buffer_pool = 26G