Jerry,
At 09:53 AM 4/13/2009, Jerry Schwartz wrote:
Sorry for top-posting, but this is getting unwieldy.
The problems with hardware in multiprocessor systems have been dealt with
long since, assuming that Intel, AMD, et al have implemented the solutions.
Ten years ago and more, I worked with machines capable of 128 processors and
they seemed to work okay.
Well having a machine with 128 processors and actually getting MySQL to
take advantage of 128 processors is a different matter entirely.
MySQL does not scale well beyond 4 processors, at least not like PostgreSql
does. MySQL seems to hit a plateau rather quickly. If XtraDb's modified
Innodb plugin scales better, then fine. But I haven't seen any benchmarks
showing the speed improvements relative to the number of processors used
and is something I'd really like to see.
Of course, there was a price difference. :<)
As others said, the major bottlenecks are likely to be internal (to the DB)
locking and disk access speed.
Of course. When it comes to MySQL, I would invest more money into more
memory and fast SSD drives rather than more CPU's. You'll get a bigger bang
for the buck. :)
Mike
Regards,
Jerry Schwartz
The Infoshop by Global Information Incorporated
195 Farmington Ave.
Farmington, CT 06032
860.674.8796 / FAX: 860.674.8341
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>-----Original Message-----
>From: mos [mailto:mo...@fastmail.fm]
>Sent: Saturday, April 11, 2009 5:07 PM
>To: Andy Smith
>Cc: mysql@lists.mysql.com
>Subject: Re: MySQL runs on 16-cores server
>
>At 08:27 AM 4/11/2009, Andy Smith wrote:
>>Hi,
>>
>> In what way can having more cores slow down MySQL (or any other app
>>for that matter)? Are you simlpy referring to the fact that some
>>mutlicore servers might be slower in single threaded preformance than
>>a higher clocked single core system? If I have a mutlicore system with
>>fast single threaded performance I wouldnt expect it to be slower in
>>almost any cases with something like a mutliprocess database system,
>>
>>thanks Andy.
>
>Andy,
> There have been many blog posts claiming MySQL does not perform
>all
>that well with multi-core processors, especially Innodb. For MyISAM the
>problem is waiting for table locks, multi-processors are not going to
>help.
>The best way to increase speed is to improve the performance of the hard
>drives. The hard drives are the biggest bottleneck, not by adding more
>processors. The new faster SSD's may be the answer. They have released
>256gb and 512gb SSD's that are super fast and claim to have have MTBF
>that
>is longer than most hard drives.
>
>Here are a few of the multi-core performance blogs.
>http://spyced.blogspot.com/2006/12/benchmark-postgresql-beats-
>stuffing.html
>http://mysqlguy.net/blog/2008/07/16/innodb-multi-core-performance
>
>http://www.mysqlperformanceblog.com/2009/03/20/ingenius-piece-of-sun-
>marketing/
>
>A better way to scale MySQL is to run multiple servers on Solaris.
>http://blogs.sun.com/mrbenchmark/entry/scaling_mysql_on_a_256
>Of course you could also try the MySQL cluster which is doing the same
>thing but on multiple machines. They get around the disk problem by
>putting
>the database in memory. So you will get a bigger bang for the buck by
>distributing the load over several machines and putting the database in
>memory, rather than adding multiple CPU's. Postgresql is one of the few
>open sources databases that will scale effectively using multiple
>processors. I wish that was the case with MySQL, but it's not.
>
>
>
>Mike
>
>
>
>>Quoting mos <mo...@fastmail.fm>:
>>
>>>
>>>Using more cores with MySQL doesn't mean it will run faster. In
>>>fact, it could slow it down. Make sure you have done benchmarking
>>>with your current computer so you can compare the difference. InnoDb
>>>and MyISAM don't scale well with multi-cores I'm afraid.
>>
>>
>
>
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