From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.sysutils.supervision.general/2553 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: "Laurent Bercot" Newsgroups: gmane.comp.sysutils.supervision.general Subject: Re: interesting claims Date: Tue, 30 Apr 2019 08:22:50 +0000 Message-ID: References: <11997211556565598@myt6-27270b78ac4f.qloud-c.yandex.net> Reply-To: "Laurent Bercot" Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="------=_MB72936876-238E-41B6-8668-2B821566ECF9" Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="118610"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: eM_Client/7.2.34711.0 To: supervision Original-X-From: supervision-return-2143-gcsg-supervision=m.gmane.org@list.skarnet.org Tue Apr 30 10:22:06 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 1hLO1e-000UYG-5v for gcsg-supervision@m.gmane.org; Tue, 30 Apr 2019 10:22:06 +0200 Original-Received: (qmail 19021 invoked by uid 89); 30 Apr 2019 08:22:25 -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 19014 invoked from network); 30 Apr 2019 08:22:25 -0000 In-Reply-To: <11997211556565598@myt6-27270b78ac4f.qloud-c.yandex.net> Xref: news.gmane.org gmane.comp.sysutils.supervision.general:2553 Archived-At: --------=_MB72936876-238E-41B6-8668-2B821566ECF9 Content-Type: text/plain; format=flowed; charset=utf-8 Content-Transfer-Encoding: quoted-printable >"suckless init is incorrect, because it has no supervision capabilities, >and thus, killing all processes but init can brick the machine." > >a rather bold claim IMO ! >where was the "correct" init behaviour specified ? >where can i learn how a "correct" init has to operate ? For instance: https://archive.fosdem.org/2017/schedule/event/s6_supervision/ https://www.youtube.com/watch?v=3DI7qE43KK5bY&t=3D7591 =20 https://www.reddit.com/r/linux/comments/2dx7k3/s6_skarnetorg_small_secure_s= upervision_software/cjxc1hj/?context=3D3 Or, as Guillermo mentioned, several posts in the ML archive. init is a subject that little study has been put into (though it is also the subject of a whole lot of talk, which says something about whether people would rather talk or study). But I think you'll find that things are different around here. >or is it true since s6-svscan already provides such respawn >capabilities ? ;-) Do not mistake causes for consequences. Things are not correct because s6 does them; s6 does things because they are correct. >there is actually NO need for a "correct" working init implementation >to provide respawn capabilities at all IMO. Then you are free to use one of the many incorrect inits out there, including sinit, Rich Felker's init, dumb-init, and others. You are definitely not alone with your opinion. However, you sound interested in process supervision, which is part of the more general idea that a machine should be made as reliable as possible *at all times* and *under any circumstances*; if you subscribe to that idea, then you will understand why init must supervise at least 1 process. >so this looks like a rather artificial and constructed argument for >the necessity of respawn functionality in an init implementation IMO. Maybe you've never bricked a device because init didn't respawn anything. I have. The "rather artificial and constructed argument" happened to me in real life, and it was a significant inconvenience. -- Laurent --------=_MB72936876-238E-41B6-8668-2B821566ECF9--