如何设置mysql参数之innodb_buffer_pool_size大小？
转自http://blog.itpub.net/10972173/viewspace-1780814/ 这篇文章讲的很不错。转载在此以供学习。
该参数定义了数据缓冲区buffer pool大小，类似于oracle的db_cache_size
mysql> show global variables like 'innodb_buffer_pool_size'; +-------------------------+-----------+ | Variable_name | Value | +-------------------------+-----------+ | innodb_buffer_pool_size | 134217728 | +-------------------------+-----------+ 1 row in set (0.00 sec)
那么如何设置该参数大小呢？首先查看运行时buffer pool相关数据指标：
mysql> show global status like 'Innodb_buffer_pool_pages_data'; +-------------------------------+-------+ | Variable_name | Value | +-------------------------------+-------+ | Innodb_buffer_pool_pages_data | 314 | +-------------------------------+-------+ 1 row in set (0.00 sec) mysql> show global status like 'Innodb_buffer_pool_pages_total'; +--------------------------------+-------+ | Variable_name | Value | +--------------------------------+-------+ | Innodb_buffer_pool_pages_total | 8191 | +--------------------------------+-------+ 1 row in set (0.00 sec) mysql> show global status like 'Innodb_page_size'; +------------------+-------+ | Variable_name | Value | +------------------+-------+ | Innodb_page_size | 16384 | +------------------+-------+ 1 row in set (0.00 sec)
上述三项指标的含义如下：
Innodb_buffer_pool_pages_data The number of pages in the InnoDB buffer pool containing data. The number includes both dirty and clean pages. Innodb_buffer_pool_pages_total The total size of the InnoDB buffer pool, in pages. Innodb_page_size InnoDB page size (default 16KB). Many values are counted in pages; the page size enables them to be easily converted to bytes
计算Innodb_buffer_pool_pages_data/Innodb_buffer_pool_pages_total*100%
当结果 > 95% 则增加 innodb_buffer_pool_size， 建议使用物理内存的 75%
当结果 < 95% 则减少 innodb_buffer_pool_size，
建议设置大小为： Innodb_buffer_pool_pages_data* Innodb_page_size * 1.05 / (1024*1024*1024)