From owner-freebsd-questions@FreeBSD.ORG Thu Nov 13 23:01:15 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EABB21065670 for ; Thu, 13 Nov 2008 23:01:15 +0000 (UTC) (envelope-from eagletree@hughes.net) Received: from smtprelay.b.hostedemail.com (smtprelay0204.b.hostedemail.com [64.98.42.204]) by mx1.freebsd.org (Postfix) with ESMTP id 9C9468FC14 for ; Thu, 13 Nov 2008 23:01:15 +0000 (UTC) (envelope-from eagletree@hughes.net) Received: from filter.hostedemail.com (b-bigip1 [10.5.19.254]) by smtprelay06.b.hostedemail.com (Postfix) with SMTP id 572AB5C2763 for ; Thu, 13 Nov 2008 23:01:14 +0000 (UTC) X-SpamScore: 1 X-Spam-Summary: 2, 0, 0, be558cc02d6e8124, 9510f55e4507d164, eagletree@hughes.net, freebsd-questions@freebsd.org, RULES_HIT:355:379:541:564:599:601:945:966:988:989:1260:1261:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1542:1593:1594:1711:1730:1747:1766:1792:1801:1981:2194:2196:2198:2199:2200:2201:2379:2393:2553:2559:2562:2693:3027:3355:3636:3865:3866:3867:3868:3869:3870:3871:3872:3873:3874:3876:3877:4250:4321:4385:4605:5007:6114:6119:7270:7652:7903:8501:8603:8778:8784:9010:9038:9121:9149:9391, 0, RBL:none, CacheIP:none, Bayesian:0.5, 0.5, 0.5, Netcheck:none, DomainCache:0, MSF:not bulk, SPF:, MSBL:none, DNSBL:none Received: from [192.168.0.3] (dpc6744118153.direcpc.com [67.44.118.153]) (Authenticated sender: eagletree@hughes.net) by omf01.b.hostedemail.com (Postfix) with ESMTP for ; Thu, 13 Nov 2008 23:01:08 +0000 (UTC) Mime-Version: 1.0 (Apple Message framework v753) In-Reply-To: References: Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Chris Pratt Date: Thu, 13 Nov 2008 15:00:56 -0800 To: FreeBSD-Questions Questions X-Mailer: Apple Mail (2.753) X-session-marker: 6561676C6574726565406875676865732E6E6574 Subject: Re: 128 Bucket Failures? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Nov 2008 23:01:16 -0000 On Nov 13, 2008, at 1:34 PM, Ivan Voras wrote: > Chris Pratt wrote: >> I have asked this before a couple of years ago but received no >> replies. I assumed that's because it's a somewhat obscure question. >> I'm still interested and thought I might try again in case someone >> new is watching this list who might know. >> >> A vmstat -z on my highest traffic server always shows the failures >> as below on 128 Bucket. It also goes to having 0 free rather soon >> after the system is restarted and never returns to having more than >> 1 free in that column and yet always has the highest number of >> requests by far. Does this mean anything significant? Is it >> something I should tune or even can be tuned? > > UMA buckets seem to be some kind of cache for SMP-optimized > allocations > - I hope someone who knows it better will explain them. > >> Here is the output of the vmstat -z with everything chopped out >> besides the 128 Bucket line. The machine it's on is an 8 core 8 GB >> Tyan and shouldn't really be starved for anything in my way of >> thinking. >> >> vmstat -z >> ITEM SIZE LIMIT USED FREE >> REQUESTS FAILURES >> >> 128 Bucket: 1048, 0, 2043, 0, >> 13591, 6511069 > > What is the server used for? > A busy webserver (about 5G Views a month, average view is 3-4 hits). Not really large pages, we keep graphics minimal. It's apache, perl cgi, mysqld. Tends to collect a lot of garbage traffic attacks on top of real traffic, both TCP and UDP. > Here's a snapshot from a very loaded apache+php+pgsql web server, > uptime > 60 days (since the last power outage): > > 16 Bucket: 76, 0, 42, 58, 125, > 0 > 32 Bucket: 140, 0, 76, 64, 183, > 0 > 64 Bucket: 268, 0, 74, 38, 438, > 11 > 128 Bucket: 524, 0, 2060, 642, 788828, > 6985 > > A generic advice would be to increase vm.kmem_size (you're using > AMD64, > right?) and see what happens. > I'll try that. I had heard this before in relation to KVA but have been concerned about trying it. If I can just change that knob and have an effect, seems worth a try. If more than one person is doing it, it must be safe? Yes, AMD64. Thank you very much.