maria-discuss team mailing list archive

[Peter Laursen <peter_laursen@xxxxxxxxxx>]

With this my.ini

*[mysqld]*
*datadir=C:/Program Files/MariaDB 10.3/data*
*port=3312*
*innodb_buffer_pool_size=500M*
*# innodb_page_cleaners=1*
*feedback=ON*
*[client]*
*port=3312*
*plugin-dir=C:/Program Files/MariaDB 10.3/lib/plugin*

. .everything is normal. Actually now SHOW VARIABLES returns "1"
for innodb_page_cleaners variable. With 4G to the bufferpool it was "4" for
the same variable.


So it seems also related to the large bufferpool setting that causes the
server to increase the # of cleaner threads if not a specific setting is
specified in configuration.  I remember from a previous discussion here
(where I complained about the amount of memory used by the MariaDB server),
that Vlad told, that the installer specifies this particular setting
depending on the amount of RAM on the system. As said, I have 32 GB RAM
here - what is (still - the box is 4 years old) somewhat unusually high on
a Windows personal workstation.

The release was probably not tested with more than the usual 4/8/16 GB RAM
on Windows (?).

For my use a moderate setting like 256M or similar works fine.  But there
are (believe it or not :-) ) Windows servers with 64G or more RAM doing a
lot of tough work ...

On Sat, Jan 20, 2018 at 6:36 PM, Peter Laursen <peter_laursen@xxxxxxxxxx>
wrote:

> One more file (mysqld2.zip) available for VV on Google Drive. This is
> server running with same configuration as before.
>
> "innodb_page_cleaners=1" did the trick. Task manager now reports 0% CPU
> for all running 'mysql' processes (that are all idle), and thus also for
> the one that is the MariaDB 10.3.4 server executable.
>
> The my.ini was created by your installer back in 12.3.0/12.3.1 days (I
> mostly run simple test cases so I do not care much about configuration and
> the box has 32 GB so I rarely increase or decrease a setting in
> configuration). Attached with the "innodb_page-cleaners" addition as
> proposed by you
>
>
>
> On Sat, Jan 20, 2018 at 6:15 PM, Vladislav Vaintroub <vvaintroub@xxxxxxxxx
> > wrote:
>
>>
>>
>> Thanks Peter,
>>
>> Just one more dump would be nice, if possible.  And also my.ini
>>
>>
>>
>> On the first glance, a couple of page cleaner threads enter busy-loop on
>> some reason. The code around coordination of them is not very easy to read,
>> so no good idea why something like this happens.
>>
>> I’d give innodb_page_cleaners=1 a try , as a “blind” attempt to
>> workaround.
>>
>>
>>
>>
>>
>> *From: *Peter Laursen <peter_laursen@xxxxxxxxxx>
>> *Sent: *Saturday, January 20, 2018 5:38 PM
>>
>> *To: *Vladislav Vaintroub <vvaintroub@xxxxxxxxx>
>> *Cc: *Maria Discuss <maria-discuss@xxxxxxxxxxxxxxxxxxx>
>> *Subject: *Re: [Maria-discuss] MariaDB 10.3.4 consumes extremely
>> muchCPUonWindows.
>>
>>
>>
>> I should have thought about compressing, obviously. That makes it 27.4
>> MB. :-)
>>
>> Now shared with vvaintroub@xxxxxxxxx. Do I need to do anything else? You
>> probably had a mail with access details?
>>
>>
>>
>> On Sat, Jan 20, 2018 at 5:32 PM, Vladislav Vaintroub <
>> vvaintroub@xxxxxxxxx> wrote:
>>
>>
>>
>>
>>
>> Oh ok, so it is a “maxi” dump.  But stull ,when you just start the
>> service, the most of the memory allocated by the process  is zeroed , thus
>> zipping the dmp should  I think make it much smaller.
>>
>> You can share via Google drive, sure.
>>
>>
>>
>>
>>
>>
>>
>> *From: *Peter Laursen <peter_laursen@xxxxxxxxxx>
>> *Sent: *Saturday, January 20, 2018 5:23 PM
>> *To: *Vladislav Vaintroub <vvaintroub@xxxxxxxxx>
>> *Cc: *Maria Discuss <maria-discuss@xxxxxxxxxxxxxxxxxxx>
>> *Subject: *Re: [Maria-discuss] MariaDB 10.3.4 consumes extremely much
>> CPUonWindows.
>>
>>
>>
>> It happens always and immediately when I start the 10.3.4 mysqld process
>> (as a service with "net start .." or from Control Panel .. Administration
>> .. Services).  I think one dump will do as it is esactly the same thing
>> everytime.
>>
>>
>>
>> The dump is 4.6 GB. I just have to figure out how to transfer it!  Is a
>> shared link to Google Drive OK (it is uploading now)?
>>
>>
>>
>> On Sat, Jan 20, 2018 at 5:14 PM, Vladislav Vaintroub <
>> vvaintroub@xxxxxxxxx> wrote:
>>
>> Hi Peter,
>>
>> Could you take a 2-3 different process dumps , when it happens?
>>
>> You do this by switching to “Detail” tab in Task manager, then
>> mysqld.exe, rightclick, “Create dump”, and mysqld.DMP will be stored in
>> temp directory.
>>
>>
>>
>> Could you then attach  minidumps  somewhere (ideally to a new bug in our
>> JIRA https://jira.mariadb.org/secure/Dashboard.jspa,  but in case you do
>> not have an account you can also send them to me so I can create a
>> bugreport on your behalf)
>>
>>
>>
>> Thanks!
>>
>>
>>
>> *From: *Peter Laursen <peter_laursen@xxxxxxxxxx>
>> *Sent: *Saturday, January 20, 2018 2:51 PM
>> *To: *Maria Discuss <maria-discuss@xxxxxxxxxxxxxxxxxxx>
>> *Subject: *[Maria-discuss] MariaDB 10.3.4 consumes extremely much CPU
>> onWindows.
>>
>>
>>
>> On a 4-core (4 physical, 8 logical cores), 3.5 Ghz box, MariaDB 10.3.4
>> consumes typically 35-40% of available CPU even when completely idle
>> according to Task Manager. Please see image.
>>
>>
>>
>> I cannot tell if previous 10.3 versions also did, as I don't have 10.3
>> running constantly in the backgorund. I just observed this now.  This does
>> not happen with MariaDB 10.1, MariaDB 10.2, MySQL 5.6, MySQL 5.7 and MySQL
>> 8.0 (all those I have starting with Windows on this box), where the
>> CPU-load is neglible unless the server is "doing real work".
>>
>>
>>
>> As a result, the CPU clock frequency is always highest possible 3.5 Ghz
>> (this CPU model is a 4th generation Intel with the option to scale down CPU
>> frequency to around 40-50% of max. when there is no need for more) when
>> MariaDB 10.3.4 is running.
>>
>>
>>
>>
>>
>>
>>
>> -- Peter
>>
>> -- Webyog
>>
>>
>>
>>
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