From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.sysutils.supervision.general/2594 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Steve Litt Newsgroups: gmane.comp.sysutils.supervision.general Subject: Re: interesting claims Date: Wed, 15 May 2019 13:22:48 -0400 Message-ID: <20190515132206.03f9736e@mydesk.domain.cxm> References: <11997211556565598@myt6-27270b78ac4f.qloud-c.yandex.net> <20190501033355.6e41e707@mydesk.domain.cxm> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="65872"; mail-complaints-to="usenet@blaine.gmane.org" To: supervision@list.skarnet.org Original-X-From: supervision-return-2184-gcsg-supervision=m.gmane.org@list.skarnet.org Wed May 15 19:22:59 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 1hQxcG-000GyO-3g for gcsg-supervision@m.gmane.org; Wed, 15 May 2019 19:22:56 +0200 Original-Received: (qmail 8719 invoked by uid 89); 15 May 2019 17:23:18 -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 8712 invoked from network); 15 May 2019 17:23:17 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; h=X-Originating-IP:Date:From:To:Subject:Message-ID:In-Reply-To:References:X-Mailer:MIME-Version:Content-Type:Content-Transfer-Encoding; s=default; d=troubleshooters.com; b=lYrpgORYdb1zEZYgMHTsgyP2HnWL/P27IU1jzWTmr/wAj8EyYq7FzBzZ3X4x25Im6mxq5MWjjnAOhuHxRhNm3RpQGQ0XlY0mmNg6iB0IjP3nNhiYItIg5HZz+l0nM1wbYVMthzgziS/oQ+kiobwqqS6OMf4LNvp979IiH6PeIc8=; DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/simple; d=troubleshooters.com; s=default; t=1557940969; bh=TGRxeCZAJjob+bRr/YX/7W5vkWM=; l=2615; h=X-Originating-IP:Date:From:To:Subject:Message-ID:In-Reply-To: References:X-Mailer:MIME-Version:Content-Type: Content-Transfer-Encoding; b=W+wntcydP7HBtFZ/oSvuMmBr7K5sWdr4zKpfd/hoVnTngizGyklhr2EBKVgECx4au 7vvTpFVmwlwwWl/qawxlv/UnRzwSgYYEqZ5NG9sEIEKIOIK5LlCqfB4DGpeKiJXX6H Y9r/quKDB1Nx9jj0K1VUrLwDEhF3f3VCVVc+sk1Y= X-Originating-IP: [72.188.224.222] In-Reply-To: X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-unknown-linux-gnu) Xref: news.gmane.org gmane.comp.sysutils.supervision.general:2594 Archived-At: On Wed, 01 May 2019 18:13:53 +0000 "Laurent Bercot" wrote: > >So Laurent's words from http://skarnet.org/software/s6/ were just > >part of a very minor family quarrel, not a big deal, and nothing to > >get worked up over. > > This very minor family quarrel is the whole difference between > having and not having a 100% reliable system, which is the whole > point of supervision. The preceding's true for you, but not for everyone. Some people, like myself, are perfectly happy with a 95% reliable system. I reboot once every 2 to 4 weeks to get rid of accumulated state, or as a troubleshooting diagnostic test. I don't think I'm alone. Some people need 100% reliable, some don't. My liking of supervision is not 100% reliability, but instead 95% reliability that is also simple, understandable, and lets me write daemons that don't have to background themselves. I don't think I'm alone. > Yes, obviously sinit and ewontfix init are greatly superior to > systemd, sysvinit or what have you. Which is why I call it a family quarrel. Some in our family have a strong viewpoint on whether PID1 supervises at least one process, and some don't. But outside our family, most are happy with systemd, which of course makes most of us retch. > That is a low bar to clear. And > the day we're happy with low bars is the day we start getting > complacent and writing mediocre software. I'd call it a not-highest bar, not a low bar. Systemd is a low bar. > > Also, you are misrepresenting my position - this is not the first > time, and it's not the first time I'm asking you to do better. > I've never said that the supervision had to be done by pid 1, actually > I insist on the exact opposite: the supervisor *does not* have to > be pid 1. What I am saying, however, is that pid 1 must supervise > *at least one process*, which is a very different thing. I'm sorry. Either I didn't know the preceding, or I forgot it. And supervising one process in PID1 makes a lot more sense than packing an entire supervisor in PID1. > s6-svscan is not a supervisor. It can supervise s6-supervise > processes, yes - that's a part of being suitable as pid 1 - but it's > not the same as being able to supervise any daemon, which is much > harder because "any daemon" is not a known quantity. I understand now. > Supervising a process you control is simple; supervising a process > you don't know the behaviour of, which is what the job of a > "supervisor" is, is more complex. I understand now. Thanks, SteveT