Date: Fri, 25 May 2007 11:40:43 +0400 From: Gleb Smirnoff <glebius@FreeBSD.org> To: Luigi Rizzo <rizzo@icir.org> Cc: Andre Oppermann <andre@FreeBSD.org>, net@FreeBSD.org Subject: Re: TCP problems after 124 days of uptime? Message-ID: <20070525074043.GH89017@glebius.int.ru> In-Reply-To: <20070524135233.D54579@xorpc.icir.org> References: <20070524182545.GF89017@FreeBSD.org> <4655EEAD.2060307@freebsd.org> <20070524135233.D54579@xorpc.icir.org>
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On Thu, May 24, 2007 at 01:52:33PM -0700, Luigi Rizzo wrote: L> On Thu, May 24, 2007 at 09:59:41PM +0200, Andre Oppermann wrote: L> > Gleb Smirnoff wrote: L> > > Yesterday two of our web servers running 6.2-PRERELEASE experienced L> > > problems with accepting TCP connections. A small percentage of SYN L> > > packets was ignored. The packets were seen in tcpdump output, but not L> > > processed by TCP stack. No accept queue overflows occured, according L> > > to 'netstat -sp tcp'. L> > > L> > > Failing to find any clue I have rebooted one of them, and after L> > > reboot is started to work flawlessly. Reboot also helped the second L> > > one. Both servers were booted at the same time - 124 days ago. L> > > L> > > Any ideas, any similar reports? L> > L> > ticks is a 32 bit signed integer and TCP isn't really aware of it L> > going negative and rolling over. This is something I'm working on L> > fixing in -current. Haven't analyzed all potential cases there yet. L> L> by chance, is your 'hz' set to 200 ? L> this might explay something, because 2^31/(86400*200) = 124.275 Nope. hz is default - 1000. -- Totus tuus, Glebius. GLEBIUS-RIPN GLEB-RIPE
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