????????

????????????????MySQL?????????????????????????????????????????????汬???

??????????

???????????????MySQL?д???????????伸??????????鷢?????????????????MySQL????????????InnoDB_DATA_READS??

???????????????????????????????????????

????1??14??????????

????2??д?????????????????update??

select pid??value from tableName where id=?;
?鯔??“id&pid”????????????????
insert into tableName values ( id??pid??value??now() ) on duplicate key update value=values(value) ;
?鵽“id&pid”?????????????
update tableName set value= ? where id=? and pid=?;

??????????????????????Щ??·???????????????????????????????????

????1????????????kernel????????????????????????????δ????????????°汾???????????

????2??innodb???????????????????з???????

????3??NUMA???????swap??????MySQL swap?о????????????????????п???????????????????

????4????????memory??????????????????????????????棬???????????????????????

????5??????????????檔????key_buffer_size????????????е??????????????????????????????????????????????????С??

????6??table cache??????檔???????????Ч????????????????????????????

????7????????mysqld???й?????????????????buglist?з?????????????ú???????????????fix???

???????FLUSH TABLES????mysqld??RSZ??????10G~

????flush????

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3018 mysql 20 0 44.2g 41g 4232 S 0.0 86.8 981:52.36 /u01/mysql/libexec/mysqld

$ free -m
total used free shared buffers cached
Mem: 48384 46335 2048 0 344 2896
-/+ buffers/cache: 43094 5289
Swap: 8191 8 8183

????flush???

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3018 mysql 20 0 34.7g 30g 4248 S 0.3 65.5 981:55.64 /u01/mysql/libexec/mysqld

$ free -m
total used free shared buffers cached
Mem: 48384 36010 12373 0 345 2898
-/+ buffers/cache: 32766 15617

????innodb??????????б仯??

———————-
BUFFER POOL AND MEMORY
———————-
Total memory allocated 26361200640; in additional pool allocated 0
Dictionary memory allocated 7723336
Buffer pool size 1572863
Free buffers 1
Database pages 1556426
Old database pages 574520
Modified db pages 4
Pending reads 0

?????????????

???????????????flush tables???????????table_open_cache ?? table_definition_cache????С????2048??512???С????