Question

After having read this page in the mysql documentation, I tried to make sense of our current InnoDB usage. Currently, we allocate 6GB of RAM for the buffer pool. Our database size is about the same. Here's the output from show engine innodb status\G (we're running v5.5)

----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 6593445888; in additional pool allocated 0
Dictionary memory allocated 1758417
Buffer pool size   393215
Free buffers       853
Database pages     360515
Old database pages 133060
Modified db pages  300
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 7365790, not young 23099457
0.00 youngs/s, 0.00 non-youngs/s
Pages read 1094342, created 185628, written 543182148
0.00 reads/s, 0.00 creates/s, 37.32 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 360515, unzip_LRU len: 0
I/O sum[2571]:cur[0], unzip sum[0]:cur[0]

I wanted to know how well we're utilizing the buffer cache. After initially glancing at the output, it appeared that we are indeed using it, based off of the Pages made young and not young have numbers in them and Buffer pool hit rate is 1000 / 10000 (which I saw elsewhere on the web that this means it's being used pretty heavily. True?)

What's throwing me through a loop is why the young-making rate and not are both at 0/1000 and the young/s and non-young/s accesses are both at 0. Those would all indicate that it's not being used at all, right?

Can anyone help make sense of this?

No correct solution

Licensed under: CC-BY-SA with attribution
Not affiliated with dba.stackexchange
scroll top