From: Sunny Bains
Date: July 1 2007 11:59pm
Subject: Re: mysql scalability.
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Jeff,

Jeff Roberson wrote:
 > I have produced a graph of mysql writes on linux and bsd:
> 
> http://people.freebsd.org/~jeff/mysqlwrite.png
> 
> This is using the sysbench oltp benchmark.  I see long periods with no
> disk activity and almost no CPU activity where all mysql threads are
> blocked on a condition variable.  This can last for a second or two. 
> Has anyone investigated it?  Is this an understood problem?

This is very interesting, as I haven't observed this during my testing.
Please post the the output of pstack (or stack trace after attaching
to the running process) during this pause.

Regards,
-sunny