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From:mos Date:April 14 2009 4:14am
Subject:Re: MySQL runs on 16-cores server
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At 02:21 PM 4/13/2009, Baron Schwartz wrote:
>Mike,
>
> > 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.
>
>You can find such benchmarks on our blog.  And Mark Callaghan and
>maybe some others have benchmarked it too.  Of course, we would love
>to see more independent benchmarks.  Vadim considers that we've solved
>scalability problems in XtraDB up to 16 cores, and I agree, though I
>am less of an expert than he is.

I did see one benchmark but more are definitely needed.

>However, many problems in MySQL
>itself remain even if all the storage engines are fixed.

Well Sun should throw some more logs on the fire and get it done.

> >> 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. :)
>
>None of MySQL's current storage engines takes advantage of a lot of
>memory or fast SSD drives either, in my opinion.  Not like they could,
>anyway.
>
>Have you seen our (or Jignesh Shah's, or Matt Yonkovit's) benchmarks
>and discussion on SSD drives?  When you disable the (unsafe,
>non-battery-backed) write cache, suddenly they aren't so fast anymore.

If you're talking about the Flash SSD's, it's not the RAM that is causing 
the problem.  These drives will slow down as the drive fills up with data. 
There is a lot of overhead needed to recover deleted space when it needs to 
write another page. These drives start out really fast, but like I said, 
they slow down as the drive fills up with data and the only way to get it 
back to its pristine speed is to do a secure erase on the drive which means 
you lose all your data. Windows 7 will have a Trim command that will help 
to minimize these delays but not eliminate them entirely. Corsair has 
announced a new Flash SSD that looks interesting 
http://hothardware.com/News/Corsair-Readying-Ultra-Fast-256GB-SSD/ but of 
course is expensive.

Now the SSD that I would like to have is the Hyperdrive 5 from 
http://www.hyperossystems.co.uk/. It is a DDR SSD and each drive has slots 
for 8 DIMM's which means it can hold up to 32GB (64GB if you can find 8GB 
DDR2's) per drive. They can be striped to give you a heck of a lot of drive 
space using RAID. And yes, they are faster than spit and will never wear out.

So if I wanted to speed up my MySQL database, I'd definitely be buying 
quite a few of these.  (Maybe later this year when I've got some cache to 
spare<g>)  Are these drives expensive? Darn right. Are they worth it? Well, 
they say time is money and if you need the results as fast as possible, 
then load 'em on up. I find most databases are disk bound and not CPU bound 
so switching to ram drives may be the best bang for the buck.  :-)

Mike




>Baron

Thread
MySQL runs on 16-cores serverMoon's Father10 Apr
  • Re: MySQL runs on 16-cores serverUwe Kiewel10 Apr
    • Re: MySQL runs on 16-cores serverWm Mussatto10 Apr
      • Re: MySQL runs on 16-cores serverAndrew Garner10 Apr
    • Re: MySQL runs on 16-cores serverMoon's Father11 Apr
      • Re: MySQL runs on 16-cores servermos11 Apr
      • Re: MySQL runs on 16-cores serverUwe Kiewel11 Apr
  • Re: MySQL runs on 16-cores servermos10 Apr
    • Re: MySQL runs on 16-cores serverAndy Smith11 Apr
      • Re: MySQL runs on 16-cores serverBaron Schwartz11 Apr
        • Re: Re: MySQL runs on 16-cores serverKen Jacobs11 Apr
        • Re: MySQL runs on 16-cores serverDavid Sparks14 Apr
          • Re: MySQL runs on 16-cores serverBaron Schwartz14 Apr
      • Re: MySQL runs on 16-cores servermos11 Apr
        • RE: MySQL runs on 16-cores serverJerry Schwartz13 Apr
          • RE: MySQL runs on 16-cores servermos13 Apr
            • Re: MySQL runs on 16-cores serverBaron Schwartz13 Apr
              • Re: MySQL runs on 16-cores servermos14 Apr
                • Re: MySQL runs on 16-cores serverBaron Schwartz14 Apr
                  • RE: MySQL runs on 16-cores serverMark14 Apr
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              • Re: find records with only numbersClaudio Nanni13 Apr
              • Re: find records with only numbersPinter Tibor13 Apr
                • Re: find records with only numbersClaudio Nanni13 Apr
            • RE: MySQL runs on 16-cores serverWm Mussatto13 Apr
    • Re: MySQL runs on 16-cores serverMoon's Father16 Apr
  • RE: MySQL runs on 16-cores servergenie.japo15 Apr