From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.cvg.de ([62.153.82.30]) by linuxtogo.org with esmtp (Exim 4.72) (envelope-from ) id 1TSxIN-000178-SZ for openembedded-core@lists.openembedded.org; Mon, 29 Oct 2012 22:54:55 +0100 Received: from ensc-virt.intern.sigma-chemnitz.de (ensc-virt.intern.sigma-chemnitz.de [192.168.3.24]) by mail.cvg.de (8.14.4/8.14.4) with ESMTP id q9TLfGsi013024 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 29 Oct 2012 22:41:17 +0100 Received: from ensc by ensc-virt.intern.sigma-chemnitz.de with local (Exim 4.76) (envelope-from ) id 1TSx5A-0004HS-76; Mon, 29 Oct 2012 22:41:16 +0100 From: Enrico Scholz To: Richard Purdie References: <1351523465-26489-1-git-send-email-enrico.scholz@sigma-chemnitz.de> <1351527102.2828.19.camel@ted> <1351531332.2828.26.camel@ted> <1351534747.2828.34.camel@ted> <1351545644.2828.41.camel@ted> Date: Mon, 29 Oct 2012 22:41:16 +0100 In-Reply-To: <1351545644.2828.41.camel@ted> (Richard Purdie's message of "Mon, 29 Oct 2012 21:20:44 +0000") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Sender: Enrico Scholz X-DSPAM-Result: Innocent X-DSPAM-Probability: 0 X-DSPAM-Confidence: 1 X-Spam-Score: -5.8 X-Spam-Level: ----- X-Spam-Tests: AWL,BAYES_00,RP_MATCHES_RCVD,SPF_NEUTRAL,DSPAM_INNOCENT X-Scanned-By: MIMEDefang 2.73 Cc: openembedded-core@lists.openembedded.org Subject: Re: [PATCH] sstate.bbclass: preserve time when unstaging files X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Oct 2012 21:54:56 -0000 Content-Type: text/plain Richard Purdie writes: >> >> >> But the real bug is the time mismatch in the autobuilders, isn't it? >> >> >> And this can/should be solved by synchronizing time by ntp on them >> >> >> instead of applying dirty hacks like resetting file dates. > ... > Imagine system A generates the sysroot headers with a time ahead of > system B. These are packaged up into an sstate tarball. System B which > has a clock at some time behind system A then downloads and uses them > so the sysroot headers become some time in the future. This can not happen when both machines are synchronizing their time with ntp. Drift to stratum-1 machine is usually <1ms in local networks and <50ms for remote ones (--> see 'ntpq' -> pe output). Nothing, which can cause the problem described by you. > The alternative is to mandate *every* system that builds are run on > use ntp Yes; a common timesource is mandatory for so nearly every distributed system. Even windoze enables (s)ntp clients by default (although its daily synchronization is just a bad joke) and I remember Fedora/Ubuntu enabling it by default too. > and add checks to sanity.bbclass to this effect since someone might > try using a sstate feed with a bad clock. This would cause no end of > problems, not least with corporate filewalls Every non-trivial network has local ntp servers which are used by clients there. > and hurt usability of the project How common is the distributed autobuilder setup? How many of these installations do not use ntp? Enrico