????????

????????????????MySQL?????????????????????????????????????????????姹�???

??????????

???????????????MySQL?写???????????浼�??????????榉�?????????????????MySQL????????????InnoDB_DATA_READS??

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

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

????2??写?????????????????update??

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

??????????????????????些??路???????????????????????????????????

????1????????????kernel????????????????????????????未????????????掳姹�???????????

????2??innodb???????????????????蟹???????

????3??NUMA???????swap??????MySQL swap?芯????????????????????锌???????????????????

????4????????memory??????????????????????????????妫�???????????????????????

????5??????????????妾�????key_buffer_size????????????械??????????????????????????????????????????????????小??

????6??table cache??????妾�???????????效????????????????????????????

????7????????mysqld???泄?????????????????buglist?蟹?????????????煤???????????????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??????????斜浠�??

———————-
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????小????2048??512???小????