Re: Using IOZone to simulate DB access patterns

From: Joshua D. Drake
Subject: Re: Using IOZone to simulate DB access patterns
Date: ,
Msg-id: 1239379233.19518.361.camel@jd-laptop.pragmaticzealot.org
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In response to: Re: Using IOZone to simulate DB access patterns  (Josh Berkus)
Responses: Re: Using IOZone to simulate DB access patterns  (Josh Berkus)
List: pgsql-performance

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Using IOZone to simulate DB access patterns  (Josh Berkus, )
 Re: Using IOZone to simulate DB access patterns  (Josh Berkus, )
  Re: Using IOZone to simulate DB access patterns  ("Joshua D. Drake", )
   Re: Using IOZone to simulate DB access patterns  (Josh Berkus, )
 Re: Using IOZone to simulate DB access patterns  (henk de wit, )
  Re: Using IOZone to simulate DB access patterns  (Jesper Krogh, )
   Re: Using IOZone to simulate DB access patterns  (henk de wit, )
    Re: Using IOZone to simulate DB access patterns  (Josh Berkus, )
     Re: Using IOZone to simulate DB access patterns  (Mark Kirkwood, )
      Re: Using IOZone to simulate DB access patterns  (Josh Berkus, )
     Re: Using IOZone to simulate DB access patterns  (Scott Carey, )
      Re: Using IOZone to simulate DB access patterns  (Josh Berkus, )
       Re: Using IOZone to simulate DB access patterns  (Scott Carey, )
      Re: Using IOZone to simulate DB access patterns  (Greg Smith, )
       Re: Using IOZone to simulate DB access patterns  (Scott Carey, )
        Re: Using IOZone to simulate DB access patterns  (Greg Smith, )
         Re: Using IOZone to simulate DB access patterns  ("M. Edward (Ed) Borasky", )
       Re: Using IOZone to simulate DB access patterns  (Mark Wong, )
        Re: Using IOZone to simulate DB access patterns  (Scott Carey, )
         Re: Using IOZone to simulate DB access patterns  (Mark Wong, )
        Re: Using IOZone to simulate DB access patterns  (Mark Wong, )
 Re: Using IOZone to simulate DB access patterns  (Laurent Laborde, )

On Fri, 2009-04-03 at 17:09 -0700, Josh Berkus wrote:
> On 4/3/09 4:12 PM, Josh Berkus wrote:
> > All,
> >
> > I've been using Bonnie++ for ages to do filesystem testing of new DB
> > servers. But Josh Drake recently turned me on to IOZone.
>
> Related to this: is IOZone really multi-threaded?  I'm doing a test run
> right now, and only one CPU is actually active.  While there are 6
> IOZone processes, most of them are idle.

In order to test real interactivity (AFAIK) with iozone you have to
launch multiple iozone instances. You also need to do them from separate
directories, otherwise it all starts writing the same file. The work I
did here:


http://www.commandprompt.com/blogs/joshua_drake/2008/04/is_that_performance_i_smell_ext2_vs_ext3_on_50_spindles_testing_for_postgresql/

Was actually with multiple bash scripts firing separate instances. The
interesting thing here is the -s 1000m and -r8k. Those options are
basically use a 1000 meg file (like our data files) with 8k chunks (like
our pages).

Based on your partitioning scheme, what is the break out? Can you
reasonably expect all partitions to be used equally?

Sincerely,

Joshua D. Drake


>
> --Josh
>
>
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