improving concurrency/performance

[Greg A. Woods]

At Mon, 7 Nov 2005 09:00:08 -0500 (EST),
John Madden wrote:
> 
> > Have you tried running something like postmark
> >
> >    http://packages.debian.org/stable/utils/postmark
> >
> > to benchmark your filesystem?
> 
> The disks are quite fast.  bonnie++, for example, shows writes at over 300MB/s. 
> What I'm finding though is that the processes aren't ever pegging them out --
> nothing ever goes into iowait.  The bottleneck is elsewhere...

The question was though:  Have you tried running PostMark?

The distinction is extremely important.

PostMark can reliably and repeatably provide very good benchmark
measurements to compare filesystem tunings and hardware configurations
and it does so in ways that mimic very well such real-world multi-user
applications such as Cyrus IMAPd.

Bonnie and Bonnie++ are very simplistic in comparison and rather useless
for determining the cause of bottlenecks in real-world applications that
may open many files at a time (unless you script frameworks to wrap them
with, in which case you are simply re-inventing something like PostMark).

-- 
						Greg A. Woods

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