From owner-freebsd-net@FreeBSD.ORG Thu Jul 24 07:56:49 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9B7ED1065673 for ; Thu, 24 Jul 2008 07:56:49 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id 538448FC1A for ; Thu, 24 Jul 2008 07:56:49 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 02E6246C53; Thu, 24 Jul 2008 03:56:49 -0400 (EDT) Date: Thu, 24 Jul 2008 08:56:48 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Mike Makonnen In-Reply-To: <48874891.2070201@wubethiopia.com> Message-ID: <20080724085515.W63347@fledge.watson.org> References: <48874891.2070201@wubethiopia.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-net@freebsd.org Subject: Re: stalled connections on recent -current 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 Jul 2008 07:56:49 -0000 On Wed, 23 Jul 2008, Mike Makonnen wrote: > I'm wondering if anyone has seen stalled connections to cvsup servers > recently. I've tried updating my mirror from several different cvsup > servers, but the connection always stalls sometime in the middle of the > update process and eventually fails with the following message in my cvsup > log file: TreeList failed: Network write failure: Connection timed out > > This is what netstat -f inet looks like during the stall: > > mtm@rogue ~% netstat -f inet > Active Internet connections > Proto Recv-Q Send-Q Local Address Foreign Address (state) > tcp4 0 32544 192.168.0.98.32829 sanmateo.ecn.pur.cvsup ESTABLISHED > tcp4 0 0 192.168.0.98.22775 xxx.xxx.xxx.xxx .ssh ESTABLISHED > > This started happening after I upgraded the system (which was a couple of > months old) to one from around July 16th. Unfortunately I don't have the old > kernel to confirm that this is indeed a kernel bug. > > Any suggestions as to how to debug this? I think I'd always start with tcpdump and see if it's at all obvious what is going on. In particular, it would be good to see if any ACKs are coming from sanmateo.ecn.pur.whatever:cvsup, and if so, what their window advertisements look like. It also doesn't hurt to confirm the state of local processes/threads attached to the socket, perhaps using procstat -k. Robert N M Watson Computer Laboratory University of Cambridge