From nobody Fri Jul 14 03:14:19 2023 X-Original-To: questions@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4R2GmR076Bz2trJw for ; Fri, 14 Jul 2023 03:14:31 +0000 (UTC) (envelope-from bc979@lafn.org) Received: from mail.sermon-archive.info (sermon-archive.info [47.181.130.121]) by mx1.freebsd.org (Postfix) with ESMTP id 4R2GmQ2J6Wz3lqT for ; Fri, 14 Jul 2023 03:14:30 +0000 (UTC) (envelope-from bc979@lafn.org) Authentication-Results: mx1.freebsd.org; dkim=none; spf=pass (mx1.freebsd.org: domain of bc979@lafn.org designates 47.181.130.121 as permitted sender) smtp.mailfrom=bc979@lafn.org; dmarc=none Received: from smtpclient.apple (mini [10.0.1.251]) by mail.sermon-archive.info (Postfix) with ESMTPSA id 4R2GmP1Ttpz2gFGq for ; Thu, 13 Jul 2023 20:14:29 -0700 (PDT) From: Doug Hardie Content-Type: multipart/alternative; boundary="Apple-Mail=_E4B1C057-BA57-498A-8CF0-EED71691F6B1" List-Id: User questions List-Archive: https://lists.freebsd.org/archives/freebsd-questions List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.600.7\)) Subject: Random sshd hangs Message-Id: <30FBD752-56E4-4A18-8EB9-54E9F4D0EF98@sermon-archive.info> Date: Thu, 13 Jul 2023 20:14:19 -0700 To: questions@freebsd.org X-Mailer: Apple Mail (2.3731.600.7) X-Virus-Scanned: clamav-milter 1.0.1 at mail X-Virus-Status: Clean X-Spamd-Result: default: False [-2.45 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-0.998]; NEURAL_HAM_SHORT(-0.75)[-0.754]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+mx]; RCVD_NO_TLS_LAST(0.10)[]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; MLMMJ_DEST(0.00)[questions@freebsd.org]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; R_DKIM_NA(0.00)[]; DMARC_NA(0.00)[lafn.org: no valid DMARC record]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; FROM_HAS_DN(0.00)[]; ARC_NA(0.00)[]; ASN(0.00)[asn:5650, ipnet:47.181.128.0/18, country:US]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[questions@freebsd.org]; RCVD_COUNT_TWO(0.00)[2] X-Rspamd-Queue-Id: 4R2GmQ2J6Wz3lqT X-Spamd-Bar: -- X-ThisMailContainsUnwantedMimeParts: N --Apple-Mail=_E4B1C057-BA57-498A-8CF0-EED71691F6B1 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii I have a FreeBSD 13.2 system that I use for software development. I = have been working on a project that uses libgd to create charts. Since = libgd is so completely documented, I have to try lots of different = things to find the one that will work. occasionally, during this = development, ssh would hang right after running my program. All = existing ssh sessions lock up and eventually time out and disconnect. = However, new ssh sessions can be established and there appears to be = nothing unusual with the system. Top shows everything is quiet. My = first thought was that my code was dumping core, but there are no core = files and there is no notice about a core dump in messages. During this = time, web access is also unavailable although the web server is running = and showing no arriving connections. After somewhere around 5-10 minutes, everything returns to normal. This = is not consistent. I can run the program 10 time fine before the next = hang. There is nothing I have found that is common to the hangs. Now = that I have the program running correctly, the system never seems to = hang again. All my ideas on what is causing this are not supported by = the facts. It's not a core dump issue. It does not appear to be an IP = issue as IP continues to work, as do new ssh connections. The web = server is sitting there completely idle. It never receives any = requests. I suppose it could be something in libgd, but it would seem = that would be continuing even now. I am a lot confused over this. I = don't want to upgrade my production servers as Those hangs would be = killers to my clients. Any ideas what this might be, or what to = investigate if it happens again? -- Doug --Apple-Mail=_E4B1C057-BA57-498A-8CF0-EED71691F6B1 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii I have a = FreeBSD 13.2 system that I use for software development.  I have = been working on a project that uses libgd to create charts.  Since = libgd is so completely documented, I have to try lots of different = things to find the one that will work.  occasionally, during this = development, ssh would hang right after running my program.  All = existing ssh sessions lock up and eventually time out and disconnect. =  However, new ssh sessions can be established and there appears to = be nothing unusual with the system.  Top shows everything is quiet. =  My first thought was that my code was dumping core, but there are = no core files and there is no notice about a core dump in messages. =  During this time, web access is also unavailable although the web = server is running and showing no arriving = connections.

After somewhere around 5-10 minutes, = everything returns to normal.  This is not consistent. I can run = the program 10 time fine before the next hang.  There is nothing I = have found that is common to the hangs.  Now that I have the = program running correctly, the system never seems to hang again. =  All my ideas on what is causing this are not supported by the = facts.  It's not a core dump issue.  It does not appear to be = an IP issue as IP continues to work, as do new ssh connections. =  The web server is sitting there completely idle.  It never = receives any requests.  I suppose it could be something in libgd, = but it would seem that would be continuing even now.  I am a lot = confused over this.  I don't want to upgrade my production servers = as Those hangs would be killers to my clients.  Any ideas what this = might be, or what to investigate if it happens = again?

-- Doug

= --Apple-Mail=_E4B1C057-BA57-498A-8CF0-EED71691F6B1--