From owner-freebsd-fs@FreeBSD.ORG Fri Apr 3 23:23:00 2015 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id A8EE7E3E for ; Fri, 3 Apr 2015 23:23:00 +0000 (UTC) Received: from smtp37.i.mail.ru (smtp37.i.mail.ru [94.100.177.97]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 1E931BD for ; Fri, 3 Apr 2015 23:22:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mail.ru; s=mail2; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:References:Subject:CC:To:MIME-Version:From:Date:Message-ID; bh=WmMHNn51iS4X+MTQBo2d9LP0zZGl15NXZyevzzGxSzg=; b=fRNVK0BNwrmQ4i7rO1x0uB9rZ9rzVyBUPjEkAzDOFw4Kw9hPHZGEHdKKnFiNQJHBsXKiGBEv5Is+3yf5fZyWS4eHSvzIZJKyqL5pREpcLyJVhxU20YQYyO0NbIWRzU7C5B7y8gS3rnXVZwMUlSHYtIip1cIfos2kqwnKo6rp7nM=; Received: from [109.188.125.8] (port=13537 helo=[192.168.0.12]) by smtp37.i.mail.ru with esmtpa (envelope-from ) id 1YeAvG-00047m-5d; Sat, 04 Apr 2015 02:22:51 +0300 Message-ID: <551F20E0.9040103@artem.ru> Date: Sat, 04 Apr 2015 02:23:12 +0300 From: Artem Kuchin User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Konstantin Belousov Subject: Re: Little research how rm -rf and tar kill server References: <1427730597.303984.247097389.165D5AAB@webmail.messagingengine.com> <5519716F.6060007@artem.ru> <1427731061.306961.247099633.0A421E90@webmail.messagingengine.com> <5519740A.1070902@artem.ru> <1427731759.309823.247107417.308CD298@webmail.messagingengine.com> <5519F74C.1040308@artem.ru> <20150331164202.GN2379@kib.kiev.ua> <551C6D9F.8010506@artem.ru> <20150402210241.GD2379@kib.kiev.ua> <551F0D4A.5040007@artem.ru> <20150403231530.GH2379@kib.kiev.ua> In-Reply-To: <20150403231530.GH2379@kib.kiev.ua> Content-Type: text/plain; charset=koi8-r; format=flowed Content-Transfer-Encoding: 8bit X-Spam: Not detected X-Mras: Ok Cc: freebsd-fs@freebsd.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Apr 2015 23:23:00 -0000 04.04.2015 2:15, Konstantin Belousov пишет: > On Sat, Apr 04, 2015 at 12:59:38AM +0300, Artem Kuchin wrote: >> 03.04.2015 0:02, Konstantin Belousov пишет: >>> On Thu, Apr 02, 2015 at 01:13:51AM +0300, Artem Kuchin wrote: >>>> 31.03.2015 19:42, Konstantin Belousov пишет: >>>>> Syncer and sync(2) perform different kind of syncs. Take the snapshot of >>>>> sysctl debug.softdep before and after the situation occur to have some >>>>> hints what is going on. >>>>> >>>>> >>>> Okay. Here is the sysctl data >>> Try this. It may be not enough, I will provide some update in this case. >>> No need to resend the sysctl data. Just test whether explicit sync(2) is >>> needed in your situation after the patch. >>> >>> >> Okay, patches, recompiled and installed new kernel. >> >> The behaviour changed a bit. >> >> Now when i start untar mysql quickly rises to 40 queries in the queue in >> opening table state. >> (before the rise was slower) >> BUT after a while (20-30 seconds) all queries are executed. >> This cycle repeated 4 times and then situation aggravated quickly. It >> happened when untar >> reached big subtree with tons of small files. >> Queue grew to 70 queries, processes went to 600 (from 450). >> I stopped untar. Waited 3 minutes. Everything was becoming even worse >> (700 process, over 100 >> queries). Issued sync. It executed for 3 seconds and voila! 20 idle >> connections, 450 processes. >> So, manual sync is still need. >> >> Also it seems like during untar shell was less responsive than before. >> >> Also, when the system managed to flush query queue systat -io shows over >> 1000 tps, but when >> they got stuck it showed only about 200 tps. > So there were the i/o ops during the stall period ? I.e., a situation > where there is clogged queue and hung processes, but no disk activity, > does not occur, even temporary ? not, such does not happen. untar is always untarring and file bases sites continue to works, just slower, but mysql queries build up, but some are executed > > In what state the hung processes are blocked ? Look at the wchan name > either in top or ps output. Are there processes in "suspfs" state ? no, after the patch all in normal state, only mysql in UFS state and some perl and http (mayb 3 or 5) in ufs state too > > Try the following patch. trying now.