From owner-freebsd-net@FreeBSD.ORG Thu May 24 21:43:58 2007 Return-Path: X-Original-To: net@FreeBSD.org Delivered-To: freebsd-net@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id A115116A421 for ; Thu, 24 May 2007 21:43:58 +0000 (UTC) (envelope-from julian@elischer.org) Received: from outD.internet-mail-service.net (outD.internet-mail-service.net [216.240.47.227]) by mx1.freebsd.org (Postfix) with ESMTP id 8AFFE13C448 for ; Thu, 24 May 2007 21:43:58 +0000 (UTC) (envelope-from julian@elischer.org) Received: from mx0.idiom.com (HELO idiom.com) (216.240.32.160) by out.internet-mail-service.net (qpsmtpd/0.32) with ESMTP; Thu, 24 May 2007 14:30:40 -0700 Received: from julian-mac.elischer.org (home.elischer.org [216.240.48.38]) by idiom.com (Postfix) with ESMTP id 4C9FD125B3F; Thu, 24 May 2007 14:30:40 -0700 (PDT) Message-ID: <46560407.9080404@elischer.org> Date: Thu, 24 May 2007 14:30:47 -0700 From: Julian Elischer User-Agent: Thunderbird 2.0.0.0 (Macintosh/20070326) MIME-Version: 1.0 To: Andre Oppermann References: <20070524182545.GF89017@FreeBSD.org> <4655EEAD.2060307@freebsd.org> In-Reply-To: <4655EEAD.2060307@freebsd.org> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Cc: Gleb Smirnoff , net@FreeBSD.org Subject: Re: TCP problems after 124 days of uptime? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 May 2007 21:43:58 -0000 Andre Oppermann wrote: > Gleb Smirnoff wrote: >> Yesterday two of our web servers running 6.2-PRERELEASE experienced >> problems with accepting TCP connections. A small percentage of SYN >> packets was ignored. The packets were seen in tcpdump output, but not >> processed by TCP stack. No accept queue overflows occured, according >> to 'netstat -sp tcp'. >> >> Failing to find any clue I have rebooted one of them, and after >> reboot is started to work flawlessly. Reboot also helped the second >> one. Both servers were booted at the same time - 124 days ago. >> >> Any ideas, any similar reports? > > ticks is a 32 bit signed integer and TCP isn't really aware of it > going negative and rolling over. This is something I'm working on > fixing in -current. Haven't analyzed all potential cases there yet. > 124 days is 32 bits at 400Hz or 30 bits at 100Hz what is the granularity of the TCP timer?