MySQL管理之道-笔记-MySQL5.7-在线调整innodb_buffer_pool_size

在线调整innodb_buffer_pool_size不用重启mysql进程
MySQL5.7以前，调整innodb_buffer_pool_size需要重启mysql进程才可以生效。
建议业务低峰时间执行

1 当前大小128M

root@localhost:mysql3306.sock [(none)]>show variables like '%innodb_buffer_pool_size%';+-------------------------+-----------+| Variable_name           | Value     |+-------------------------+-----------+| innodb_buffer_pool_size | 134217728 |+-------------------------+-----------+row in set (0.03 sec)root@localhost:mysql3306.sock [(none)]>select 134217728/1024/1024;  +---------------------+| 134217728/1024/1024 |+---------------------+|        128.00000000 |+---------------------+row in set (0.00 sec)

2 动态调整为256M

root@localhost:mysql3306.sock [(none)]>set global innodb_buffer_pool_size = 256*1024*1024;Query OK, 0 rows affected (0.18 sec)root@localhost:mysql3306.sock [(none)]>show variables like '%innodb_buffer_pool_size%';+-------------------------+-----------+| Variable_name           | Value     |+-------------------------+-----------+| innodb_buffer_pool_size | 268435456 |+-------------------------+-----------+row in set (0.02 sec)root@localhost:mysql3306.sock [(none)]>select 268435456/1024/1024;+---------------------+| 268435456/1024/1024 |+---------------------+|        256.00000000 |+---------------------+row in set (0.00 sec)root@localhost:mysql3306.sock [(none)]>select version();+------------+| version()  |+------------+| 5.7.18-log |+------------+row in set (0.03 sec)

调整时，内部会把数据页移动到一个新的位置，单位是块。如果想提升移动速度，则需要调整
innodb_buffer_pool_chunk_size的参数大小，默认是128M

innodb_buffer_pool_size/innodb_buffer_pool_instances = innodb_buffer_pool_chunk_size的参数大小，默认是128M