From owner-freebsd-current@freebsd.org Thu May 12 16:44:55 2016 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 61CA0B37F6A for ; Thu, 12 May 2016 16:44:55 +0000 (UTC) (envelope-from ohartman@zedat.fu-berlin.de) Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2421713BF for ; Thu, 12 May 2016 16:44:55 +0000 (UTC) (envelope-from ohartman@zedat.fu-berlin.de) Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost.zedat.fu-berlin.de (Exim 4.85) for freebsd-current@freebsd.org with esmtps (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (envelope-from ) id <1b0tjI-00018T-P5>; Thu, 12 May 2016 18:44:52 +0200 Received: from x5ce120ec.dyn.telefonica.de ([92.225.32.236] helo=thor.walstatt.dynvpn.de) by inpost2.zedat.fu-berlin.de (Exim 4.85) for freebsd-current@freebsd.org with esmtpsa (TLSv1.2:AES128-GCM-SHA256:128) (envelope-from ) id <1b0tjI-000SCu-Au>; Thu, 12 May 2016 18:44:52 +0200 Date: Thu, 12 May 2016 18:46:34 +0200 From: "O. Hartmann" To: FreeBSD CURRENT Subject: [CURRENT]: Broken ssh: Fssh_packet_write_wait: Connection to XXX.XXX.XXX.XXX port 22: Broken pipe Message-ID: <20160512184634.10610420.ohartman@zedat.fu-berlin.de> Organization: FU Berlin X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.29; amd64-portbld-freebsd11.0) MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/0HhSL9GZpG879UuqNx9Wt9G"; protocol="application/pgp-signature" X-Originating-IP: 92.225.32.236 X-ZEDAT-Hint: A X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 May 2016 16:44:55 -0000 --Sig_/0HhSL9GZpG879UuqNx9Wt9G Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Since a couple of time now (~1 1/2 months) I'm bothered by very unreliable = ssh connections betwwwn CURRENT boxes. Very often, the connection simply dies w= ith Fssh_packet_write_wait: Connection to XXX.XXX.XXX.XXX port 22: Broken pipe This is even worse than annoying, how to maintain systems remotely with suc= h unreliable connections? The problem seems to be related to CURRENT, but I do not have any truthfull= reference since we use only one 10.3-STABLE box. I will describe my observations, hopefully someone can make a picture out o= f it.=20 The "Broken pipe" which kills poudriere sessions, buildworld (worse, if a i= nstallworld gets caught by the Broken pipe!) are between CURRENT systems, the "controli= ng" box is a CURRENT box with X11/xterm from which I start the ssh sesseion. Connections from such X11/xterm systems no remote servers seem to be "stabl= e" as long as I do not open a second ssh connection. But this is not much reliable, just = an observation. Sometimes an open ssh connection lasts tens of minutes, even w= ith some "noise" (output) on the terminal or relaxed (static blinking cursor awaiting further input), but in other cases, a connections dies very quickly. It see= ms to me that this behaviour is random. It occurs under load or on relaxed systems random= ly, sometimes very quick, sometimes it lasts longer. The observation of today about the s= ingle-ssh connection is weak, but I have a strange suspicion that concurrent sessions= trigger the drops faster. In any case, the ssh session seems to go "asleep" after a whi= le: that happens randomly over a time or very quickly - I have no clue what triggers= this erratic behaviour. It takes a while before the ssh connection/xterm takes input aga= in - up to 30 seconds (even on fast, relaxed systems) or as final consequence, a "Broken = pipe". Today, I made another experience. Having some autofs mounts on several syst= ems, performance/bandwith seemed very bad/slow (both server and clients are CURR= ENT, most recent builds as of today). I reported earlier on this list about shaky and slow performance in conjunc= tion with the ssh problem, but I wasn't able to figure out what causes the problem! And I= 'm wondering about nobody else is facing such dramatic dropouts of the ssh connections o= r performance issues. I think I will issue a PR on this, too. Kind regards, O. Hartmann --Sig_/0HhSL9GZpG879UuqNx9Wt9G Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJXNLNqAAoJEOgBcD7A/5N8/ncIAI+VfsO+ijMzJTQqySvdRNQN +kYo37Hz7n/I/KFu7jGLWJXXtzOYJiP3BTCiE19iFCkMIad7297tP1SRT9O04gFJ khTVxLk2FoaM5+gN3ep5MevHXLPcYCmcERgVc5K331C77KzHivuzfBqIiEzgNsoM UlTRhsfCEDtwxn7gcuSEOSzxCf+ypyvBDZtszFcd7sEXS9V6buNNIKeGZYsDU62F H4aFStoqE6y9GKuv2g+v0H/IXKOA7foPdTj6Mwc0vPaau1+4vJxDWbMu0BRaW1UD iL9u304QWg8rtJdphJPP2AbpitW3s8Q39PA1qMErwL8a2A2L+OtZOj08D7vHHu8= =iyio -----END PGP SIGNATURE----- --Sig_/0HhSL9GZpG879UuqNx9Wt9G--