How normal mysql server 5.1 uses multiple cores

Hi All,

Can anyone provide me any input on How to make mysql use multiple CPU
cores avaliable.

I am sorry if I am souding very unclear with this. Let me know if you have
any questions.

Thanks in advance.

--
Regards,
Manasi Save
Artificial Machines Pvt Ltd.




--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org

Re: How normal mysql server 5.1 uses multiple cores

--0016e644cd96ff314d04791c1a39
Content-Type: text/plain; charset=ISO-8859-1

MySQL is already a multithreaded process, even though you only see a single
process. Note that it doesn't scale very well above eight or so cores,
especially InnoDB iirc.

If you are wondering about parallel query execution (that is, splitting a
single query over multiple cores for faster execution), that is currently
not supported by MySQL.


On Tue, Nov 24, 2009 at 12:02 PM, Manasi Save <
manasi.save@artificialmachines.com> wrote:

> Hi All,
>
> Can anyone provide me any input on How to make mysql use multiple CPU
> cores avaliable.
>
> I am sorry if I am souding very unclear with this. Let me know if you have
> any questions.
>
> Thanks in advance.
>
> --
> Regards,
> Manasi Save
> Artificial Machines Pvt Ltd.
>
>
>
>
> --
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe: http://lists.mysql.com/mysql?unsub=vegivamp@tuxera.be
>
>

--0016e644cd96ff314d04791c1a39--

Re: How normal mysql server 5.1 uses multiple cores

Hi Johan,

Thanks for the quick response.

Is there any command available in mysql using which I can check how much
CPU is being used by each mysql thread. Or any article where how mysql
multi-threading works.

--
Thanks and Regards,
Manasi Save
Artificial Machines Pvt Ltd.

> MySQL is already a multithreaded process, even though you only see a
> single
> process. Note that it doesn't scale very well above eight or so cores,
> especially InnoDB iirc.
>
> If you are wondering about parallel query execution (that is, splitting a
> single query over multiple cores for faster execution), that is currently
> not supported by MySQL.
>
>
> On Tue, Nov 24, 2009 at 12:02 PM, Manasi Save <
> manasi.save@artificialmachines.com> wrote:
>
>> Hi All,
>>
>> Can anyone provide me any input on How to make mysql use multiple CPU
>> cores avaliable.
>>
>> I am sorry if I am souding very unclear with this. Let me know if you
>> have
>> any questions.
>>
>> Thanks in advance.
>>
>> --
>> Regards,
>> Manasi Save
>> Artificial Machines Pvt Ltd.
>>
>>
>>
>>
>> --
>> MySQL General Mailing List
>> For list archives: http://lists.mysql.com/mysql
>> To unsubscribe: http://lists.mysql.com/mysql?unsub=vegivamp@tuxera.be
>>
>>
>



--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org

Re: How normal mysql server 5.1 uses multiple cores

--000325579eb2a954c604791c57be
Content-Type: text/plain; charset=ISO-8859-1

the command 'top -H' will show you the individual threads with their CPU
use, but I'm afraid I don't know how to link that up with a MySQL 'show
processlist'.


On Tue, Nov 24, 2009 at 12:22 PM, Manasi Save <
manasi.save@artificialmachines.com> wrote:

> Hi Johan,
>
> Thanks for the quick response.
>
> Is there any command available in mysql using which I can check how much
> CPU is being used by each mysql thread. Or any article where how mysql
> multi-threading works.
>
> --
> Thanks and Regards,
> Manasi Save
> Artificial Machines Pvt Ltd.
>
> > MySQL is already a multithreaded process, even though you only see a
> > single
> > process. Note that it doesn't scale very well above eight or so cores,
> > especially InnoDB iirc.
> >
> > If you are wondering about parallel query execution (that is, splitting a
> > single query over multiple cores for faster execution), that is currently
> > not supported by MySQL.
> >
> >
> > On Tue, Nov 24, 2009 at 12:02 PM, Manasi Save <
> > manasi.save@artificialmachines.com> wrote:
> >
> >> Hi All,
> >>
> >> Can anyone provide me any input on How to make mysql use multiple CPU
> >> cores avaliable.
> >>
> >> I am sorry if I am souding very unclear with this. Let me know if you
> >> have
> >> any questions.
> >>
> >> Thanks in advance.
> >>
> >> --
> >> Regards,
> >> Manasi Save
> >> Artificial Machines Pvt Ltd.
> >>
> >>
> >>
> >>
> >> --
> >> MySQL General Mailing List
> >> For list archives: http://lists.mysql.com/mysql
> >> To unsubscribe:
> http://lists.mysql.com/mysql?unsub=vegivamp@tuxera.be
> >>
> >>
> >
>
>
>
> --
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe: http://lists.mysql.com/mysql?unsub=vegivamp@tuxera.be
>
>

--000325579eb2a954c604791c57be--

Re: How normal mysql server 5.1 uses multiple cores

2009/11/24 Johan De Meersman :
> If you are wondering about parallel query execution (that is, splitting a
> single query over multiple cores for faster execution), that is currently
> not supported by MySQL.

[offtopic]
Probably is something stupid, but could that be done with ndb cluster
on a single host? Anyway, I suppose performance loses on distributed
joins and so on would outcome multiple-core benefits. And for most
queries, the bottleneck is usually on disk access, not processor. Has
anybody done any serious testing on this?

--
Jaime Crespo
MySQL & Java Instructor
Warp Networks


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org

Re: How normal mysql server 5.1 uses multiple cores

At 06:44 AM 11/24/2009, you wrote:
>2009/11/24 Johan De Meersman :
> > If you are wondering about parallel query execution (that is, splitting a
> > single query over multiple cores for faster execution), that is currently
> > not supported by MySQL.
>
>[offtopic]
>Probably is something stupid, but could that be done with ndb cluster
>on a single host? Anyway, I suppose performance loses on distributed
>joins and so on would outcome multiple-core benefits. And for most
>queries, the bottleneck is usually on disk access, not processor. Has
>anybody done any serious testing on this?

Jaime,
Well it all depends on the SQL that is being executed, the table
structure and the size of the query. Now for a particular case you can do
your own benchmarking quite easily to see if disk speed is more relevant
than CPU speed. Copy your tables into a MEMORY table and do the joins
there. Compare that to a disk join (reset the query cache) and see the
improvement. I'm guessing you will probably see a 300% improvement over
disk. As mentioned earlier, MySQL does not scale up very well with multiple
processors which is why it is better to scale out horizontally with clusters.

Mike


--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe: http://lists.mysql.com/mysql?unsub=gcdmg-mysql-2@m.gmane.org