Date: Thu, 12 May 2016 18:46:34 +0200 From: "O. Hartmann" <ohartman@zedat.fu-berlin.de> To: FreeBSD CURRENT <freebsd-current@freebsd.org> 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>
index | next in thread | raw e-mail
[-- Attachment #1 --] 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 with 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 such 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 of it. The "Broken pipe" which kills poudriere sessions, buildworld (worse, if a installworld gets caught by the Broken pipe!) are between CURRENT systems, the "controling" 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 "stable" 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 with some "noise" (output) on the terminal or relaxed (static blinking cursor awaiting further input), but in other cases, a connections dies very quickly. It seems to me that this behaviour is random. It occurs under load or on relaxed systems randomly, sometimes very quick, sometimes it lasts longer. The observation of today about the single-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 while: 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 again - 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 systems, performance/bandwith seemed very bad/slow (both server and clients are CURRENT, most recent builds as of today). I reported earlier on this list about shaky and slow performance in conjunction 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 or performance issues. I think I will issue a PR on this, too. Kind regards, O. Hartmann [-- Attachment #2 --] -----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-----help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20160512184634.10610420.ohartman>