From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.sysutils.supervision.general/2826 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Oliver Schad Newsgroups: gmane.comp.sysutils.supervision.general Subject: Re: The "Unix Philosophy 2020" document Date: Sun, 29 Dec 2019 21:32:49 +0100 Organization: Automatic Server AG Message-ID: <20191229213249.576369d0@dickeberta> References: <20190927083816.tectynx7dzlfcvb7@caspervector> <20191012173743.drzlgnrw4hib6hh4@caspervector> <20191117062644.lt6wfmqwijqqhc5w@caspervector> <20191226175258.o2nsregew6tlqlbu@caspervector> <20191227112309.3fow6vynss2ifw4t@CasperVector> <20191228022440.GA194581@cube> <20191228014608.1dc7f43e@mydesk.domain.cxm> <20191228133735.GA198054@cube> <20191228184156.5a1a590f@flunder> <20191229160739.GA223426@cube> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/62Ms2U2RSL3_IPczDD1J.=p"; protocol="application/pgp-signature" Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="86674"; mail-complaints-to="usenet@blaine.gmane.org" To: supervision@list.skarnet.org Original-X-From: supervision-return-2415-gcsg-supervision=m.gmane.org@list.skarnet.org Sun Dec 29 21:32:59 2019 Return-path: Envelope-to: gcsg-supervision@m.gmane.org Original-Received: from alyss.skarnet.org ([95.142.172.232]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1ilfFC-000MPt-Qe for gcsg-supervision@m.gmane.org; Sun, 29 Dec 2019 21:32:58 +0100 Original-Received: (qmail 19053 invoked by uid 89); 29 Dec 2019 20:33:23 -0000 Mailing-List: contact supervision-help@list.skarnet.org; run by ezmlm Original-Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Original-Received: (qmail 19046 invoked from network); 29 Dec 2019 20:33:23 -0000 In-Reply-To: <20191229160739.GA223426@cube> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Xref: news.gmane.org gmane.comp.sysutils.supervision.general:2826 Archived-At: --Sig_/62Ms2U2RSL3_IPczDD1J.=p Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sun, 29 Dec 2019 18:07:39 +0200 Alex Suykov wrote: > Er, that whole quoted part, including the last sentence, is about > using cgroups to supervise processes. Not about the use of cgroups in > general. I can't think of any other use cases where cgroup > supervision would be useful, other than for double-forking daemons. Agree. > Also, wrt process supervision, calling it a side effect is bit > misleading. The interfaces are not really made for that kind of use > at all. Strictly speaking, anything doing kill `cat .../cgroup.procs` > is racy and unreliable. Including that runcg tool that I wrote. In > practice, the race is pretty much irrelevant, but it's still there, > inherent to the interfaces. Yes, that is true - but the freezing cgroup can handle that race. As I already mentioned it has corner cases, where a freezed process can't be killed. As far as I read with cgroup v2 this corner case is gone. This whole thing itself (double forking) is a corner case and you should somewhen(!) give an easy interface to catch that case in a supervision toolbox(!) IMHO. You can think of providing that for marketing purposes earlier. However supporting system specific stuff like cgroups is useful (and not just a marketing gag to compete against systemd) and you should support that in a system specific toolbox as part of the supervision suite (read as it is referenced as optional dependency or directly packaged). I don't see a reason to implement such stuff inside of a supervision daemon itself - a system specific toolbox is the right place for that. Best Regards Oli --=20 Automatic-Server AG =E2=80=A2=E2=80=A2=E2=80=A2=E2=80=A2=E2=80=A2 Oliver Schad Gesch=C3=A4ftsf=C3=BChrer Turnerstrasse 2 9000 St. Gallen | Schweiz www.automatic-server.com | oliver.schad@automatic-server.com Tel: +41 71 511 31 11 | Mobile: +41 76 330 03 47 --Sig_/62Ms2U2RSL3_IPczDD1J.=p Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl4JDXEACgkQRilxUUuWlvCl5ACfRwt+e770Xd0disn05oTcebi6 avYAoLygQJ/B0HmonTqlUqFm6MmpXfjN =ymDF -----END PGP SIGNATURE----- --Sig_/62Ms2U2RSL3_IPczDD1J.=p--