MySQL Bugs: #72423: buffer_pool_pages_data larger than buffer_pool_pages

Bug #72423	buffer_pool_pages_data larger than buffer_pool_pages_total
Submitted:	22 Apr 2014 18:01	Modified:	17 Jul 2014 22:13
Reporter:	Shlomi Noach (OCA)	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: InnoDB storage engine	Severity:	S3 (Non-critical)
Version:	5.6.17-log	OS:	Linux
Assigned to:		CPU Architecture:	Any
Tags:	buffer pool, flushing, innodb

Description:
While trying to figure out why I have excessive flushing on InnoDB (if you're interested, please read: http://code.openark.org/blog/mysql/the-mystery-of-mysql-5-6-excessive-buffer-pool-flushing), I issued the following:

mysql> select name, count from INNODB_METRICS where name like '%buff%pool%page%';
+-------------------------+----------+
| name                    | count    |
+-------------------------+----------+
| buffer_pool_pages_total |  3014627 |
| buffer_pool_pages_misc  | -1808588 |
| buffer_pool_pages_data  |  4822230 |
| buffer_pool_pages_dirty |   488383 |
| buffer_pool_pages_free  |      985 |
+-------------------------+----------+

The buffer_pool_pages_total makes sense: innodb_buffer_pool_size=49392123904, innodb_page_size=16384. 49392123904/16384 = 3014656 which is roughly 3014627 buffer_pool_pages_total above.

buffer_pool_pages_data does NOT make sense since it is larger (and substantially so) than buffer_pool_pages_total,
and of course buffer_pool_pages_misc is invalid.

How to repeat:
Not sure, but this happens on all 6 servers upgraded from 5.5 to 5.6 without any configuration changes.

Suggested fix:
all values must be non-negative.

Do you have compressed barracuda tables?
Also:  http://bugs.mysql.com/bug.php?id=59550

I do. ROW_FORMAT=COMPRESSED, key block size is default (8)

Thank you for the feedback.

Closed as duplicate of bug #59550