From owner-freebsd-performance@FreeBSD.ORG Wed Aug 11 20:15:36 2010 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A3FD51065672 for ; Wed, 11 Aug 2010 20:15:36 +0000 (UTC) (envelope-from julian@elischer.org) Received: from out-0.mx.aerioconnect.net (out-0-15.mx.aerioconnect.net [216.240.47.75]) by mx1.freebsd.org (Postfix) with ESMTP id 5E1438FC0C for ; Wed, 11 Aug 2010 20:15:36 +0000 (UTC) Received: from idiom.com (postfix@mx0.idiom.com [216.240.32.160]) by out-0.mx.aerioconnect.net (8.13.8/8.13.8) with ESMTP id o7BK0B03026245; Wed, 11 Aug 2010 13:00:11 -0700 X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e Received: from julian-mac.elischer.org (h-67-100-89-137.snfccasy.static.covad.net [67.100.89.137]) by idiom.com (Postfix) with ESMTP id 902432D6012; Wed, 11 Aug 2010 13:00:10 -0700 (PDT) Message-ID: <4C630156.6060203@elischer.org> Date: Wed, 11 Aug 2010 13:00:22 -0700 From: Julian Elischer User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10.4; en-US; rv:1.9.1.11) Gecko/20100711 Thunderbird/3.0.6 MIME-Version: 1.0 To: markham breitbach References: <4C62D827.2030409@ssimicro.com> <949C0FF2-04AA-4440-82B0-F44A13B8F0C2@mac.com> <4C62F272.4030703@ssimicro.com> In-Reply-To: <4C62F272.4030703@ssimicro.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.67 on 216.240.47.51 Cc: freebsd-performance@freebsd.org Subject: Re: massive load average spikes X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Aug 2010 20:15:36 -0000 On 8/11/10 11:56 AM, markham breitbach wrote: > > > On 11/08/10 11:59 AM, Chuck Swiger wrote: >> Hi-- [...] > > Sorry for the limited data, It's hard to know where to draw the line between useful data > and information overload, but I'm more than happy to supply whatever other info you might > find useful. > > I did take a look at my dovecot logs, and there are not more than a couple of failed auth > attempts in any given minute. Sendmail logs don't show any excessive activity when LA > spikes either. > > "vmstat -w1" shows occasional spikes of processes in the run queue, but that doesn't > usually correlate to spikes in load average (although sometimes it is close). [...] > load average is a time averaged thing and in the case of a 'thundering herd' problem you will see the LA spike up and come down again over time. Do you see any problem as a result of this? Or is it just curiosity? you might want to use KTR or ktrace with scheduling events if you really want to see the reason for this. It could just be a sampling error when some 'tick' coincides with the sampling.. > > Wed Aug 11 12:40:55 MDT 2010 > 0.60 3.38 3.79 > 0.60 3.38 3.79 > 0.55 3.33 3.77 > 0.55 3.33 3.77 > 0.55 3.33 3.77 > 0.55 3.33 3.77 > 40.94 11.66 6.70 > 40.94 11.66 6.70 > 40.94 11.66 6.70 > 40.94 11.66 6.70 > Wed Aug 11 12:41:05 MDT 2010 > 40.94 11.66 6.70 > 40.94 11.66 6.70 > 37.67 11.46 6.66 > 37.67 11.46 6.66 > 37.67 11.46 6.66 > 37.67 11.46 6.66 > 37.67 11.46 6.66 > 34.65 11.27 6.63 > 34.65 11.27 6.63 > 34.65 11.27 6.63 > > > >