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From:Adam Date:November 10 2012 8:38pm
Subject:InnoDB buffer pool write requests
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Hi,

On mysql-server-5.5.27, "show engine innodb status" prints buffer pool
statistics, in particular the number of file page reads and writes for
each of the buffer pool instance. I am trying to extend its
functionality to keep track of the number of writes (updates) and
reads per each page of the database (whether or not it currently
resides in the buffer pool). I am not concerned with performance
overhead as this function is meant to be called only sparingly (for my
research).

I have figured out how to keep track of the number of reads per page
(by keeping track of buf_pool_info_t.n_page_gets) However, I don't
know how to keep track of writes per page. I noticed that
buf0buf.c:buf_page_io_complete() maintains the number of file page
writes from buffer pool to database file. But this is not what I want,
as a page might get updated multiple times while in memory but only
get written to disk once. I am interested in counting the former. Is
there a entry function which maintains the number of write requests to
each page of the database or each page of the bufferpool?

Please let me know!

Thanks,

Adam
Thread
InnoDB buffer pool write requestsAdam10 Nov