SHOW INNODB STATUS: BUFFER POOL AND MEMORY


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BUFFER POOL AND MEMORY
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Total memory allocated 13505821346; in additional pool allocated 17936896
Buffer pool size 768000
Free buffers 5
Database pages 728656
Modified db pages 108067
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages read 31203802, created 3930786, written 131784156
4.50 reads/s, 0.00 creates/s, 131.22 writes/s
Buffer pool hit rate 1000 / 1000


Pending reads and writes are pending requests on buffer pool.
Different types of IO are used by Innodb, think of it like a IO scheduler for INNODB itself.

LRU pages - dirty pages which were not accessed long time
flush list - old pages which need to be flushed by checkpointing process
single page - independent page writes.