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I am running some queries on some large tables. I tuned my settings so that innodb_buffer_pool_size = 16G and when I look at show variables, I see that 16G is allocated to the instance.

I am running a 64bit machine with 24G of ram and have mysql server 64 bit installed. While my query is running, only 6.08GB of physical memory is being used total and only about 2GB for mysql.

Resource Monitor tells me that the mysqld.exe process has a commit of 18,699,968 but a working set of 2,069,572.

What do I need to do to make this Windows server use the full 16G of ram during queries?

I am using the 32 bit version of MySQL Workbench to run my queries btw. Using the command line query also only uses about 2GB of memory as well.

Result of requested query:

INNODB_BUFFER_POOL_PAGES_DATA   426.80 MB
INNODB_BUFFER_POOL_PAGES_DIRTY  0.00 B 
INNODB_BUFFER_POOL_PAGES_FLUSHED    16.00 KB
INNODB_BUFFER_POOL_PAGES_FREE   15.58 GB
INNODB_BUFFER_POOL_PAGES_MISC   16.00 KB
INNODB_BUFFER_POOL_PAGES_TOTAL  16.00 GB

Just a little background, I am not running a live server for a web page or application. I basically imported a 600k row table and a 33k row table and need to perform matches against each and then output the results into csvs. The queries are taking forever, and I would like the server to use the maximum amount of ram to hurry things up. Based on my results above, let me know what I can do.

  • What version of MySQL ?? Run SELECT VERSION(); – RolandoMySQLDBA Aug 8 '14 at 20:40
  • 5.6.19 is the version – Christopher Aug 8 '14 at 21:01
  • I adjusted my query and was able to get more speed. I will accept your answer though for the level of detail and assume that my system is running okay, it was just slow due to my original query. – Christopher Aug 8 '14 at 22:28
2

You need to be aware of what the InnoDB Buffer Pool breakdown is from the status variables

Please run the following query

select var,concat(numunit,' ',unit) size from
(
    select var,format(num/power(1024,ex),2) numunit,SUBSTR(units,ex*2+1,2) unit
    from
    (
        select var,num,FLOOR(LOG(IF(num=0,1,num))/LOG(1024)) ex
        from
        (
            select variable_name var,variable_value*pagesize num
            from information_schema.global_status AAA,
            (
                select variable_value pagesize
                from information_schema.global_status
                where variable_name='innodb_page_size'
            ) BBB
            where AAA.variable_name like 'innodb_buffer_pool_pages%'
        ) AA
    ) A,(select 'B KBMBGBTB' units) B
) M;

This will gives a status of the Buffer Pool's current usage and how much data has been flushed from it.

Example

mysql> select var,concat(numunit,' ',unit) size from
    -> (
    ->     select var,format(num/power(1024,ex),2) numunit,SUBSTR(units,ex*2+1,2) unit
    ->     from
    ->     (
    ->         select var,num,FLOOR(LOG(IF(num=0,1,num))/LOG(1024)) ex
    ->         from
    ->         (
    ->             select variable_name var,variable_value*pagesize num
    ->             from information_schema.global_status AAA,
    ->             (
    ->                 select variable_value pagesize
    ->                 from information_schema.global_status
    ->                 where variable_name='innodb_page_size'
    ->             ) BBB
    ->             where AAA.variable_name like 'innodb_buffer_pool_pages%'
    ->         ) AA
    ->     ) A,(select 'B KBMBGBTB' units) B
    -> ) M;
+----------------------------------+-----------+
| var                              | size      |
+----------------------------------+-----------+
| INNODB_BUFFER_POOL_PAGES_DATA    | 9.17 GB   |
| INNODB_BUFFER_POOL_PAGES_DIRTY   | 0.00 B    |
| INNODB_BUFFER_POOL_PAGES_FLUSHED | 179.59 GB |
| INNODB_BUFFER_POOL_PAGES_FREE    | 32.00 KB  |
| INNODB_BUFFER_POOL_PAGES_MISC    | 177.05 MB |
| INNODB_BUFFER_POOL_PAGES_TOTAL   | 9.34 GB   |
+----------------------------------+-----------+
6 rows in set (0.00 sec)

mysql>

I have the following

  • 9.34G Buffer Pool (9566 MB)
  • 9.17G of Data
  • 177 .05 MB for the adaptive hash index and administrative stuff
  • 32 KB free
  • No dirty pages

Why is INNODB_BUFFER_POOL_PAGES_FLUSHED so sky high at 179.59 GB ?

That is the amount of flushing the buffer pool has had to commit to the InnoDB Architecture.

Here is a diagram

InnoDB Architecture

In my case,

mysql> SELECT variable_value INTO @Uptime FROM information_schema.global_status WHERE variable_name='Uptime'; SELECT NOW() "Right Now",MySQLStartupTime "MySQL Started",TimeDisplay "MySQL Has Been Running For" FROM (SELECT NOW() - INTERVAL @Uptime SECOND MySQLStartupTime) M,(SELECT TRIM(REPLACE(CONCAT(IF(dy=0,'',IF(dy=1,'1 day ',CONCAT(dy,' days '))),IF(hr=0,'',IF(hr=1,'1 hour ', CONCAT(hr,' hours  '))),IF(mn=0,'',IF(mn=1,'1 minute ',CONCAT(mn,' minutes '))),IF(sc=0,'',IF(sc=1,'1 second ',CONCAT(sc,' seconds ')))),'  ',' ')) TimeDisplay FROM (SELECT dy,hr,mn,MOD(sec_aaaa,60) sc FROM (SELECT dy,hr,FLOOR((sec_aaa - dy*86400 - hr*3600)/60) mn,sec_aaa sec_aaaa FROM (SELECT dy,FLOOR((sec_aa - (dy*86400))/3600) hr,sec_aa sec_aaa FROM (SELECT FLOOR(sec_a/86400) dy,sec_a sec_aa FROM (SELECT @Uptime sec_a) A) AA) AAA) AAAA) B) N;
Query OK, 1 row affected (0.02 sec)

+---------------------+---------------------+-------------------------------+
| Right Now           | MySQL Started       | MySQL Has Been Running For    |
+---------------------+---------------------+-------------------------------+
| 2014-08-08 17:13:42 | 2014-06-26 16:38:56 | 43 days 34 minutes 46 seconds |
+---------------------+---------------------+-------------------------------+
1 row in set (0.00 sec)

MySQL has been up for 43 days. It has flushed 179GB out of the Buffer Pool.

The Buffer Pool has to flush dirty pages to three places

  • the Log Buffer
  • the Insert Buffer
  • the .ibd file for the Table

I have a rather busy server and it's a VM.

In your case, 18,699,968 K of flushes from a 2,069,572 K Buffer Pool is nothing to worry about.

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