From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.sysutils.supervision.general/2035 Path: news.gmane.org!not-for-mail From: Jean-Michel Bruenn Newsgroups: gmane.comp.sysutils.supervision.general Subject: Re: hello - hanging services Date: Wed, 18 Aug 2010 18:02:05 +0200 Organization: IP Minds Message-ID: <20100818180205.5be254c7.jean.bruenn@ip-minds.de> References: <20100817190803.41e8257f.jean.bruenn@ip-minds.de> <20100817192422.a157e85f.jean.bruenn@ip-minds.de> <20100818105735.GA13364@skarnet.org> <20100818170635.a5a24d3f.jean.bruenn@ip-minds.de> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1282147334 11113 80.91.229.12 (18 Aug 2010 16:02:14 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 18 Aug 2010 16:02:14 +0000 (UTC) To: supervision@list.skarnet.org Original-X-From: supervision-return-2270-gcsg-supervision=m.gmane.org@list.skarnet.org Wed Aug 18 18:02:13 2010 Return-path: Envelope-to: gcsg-supervision@lo.gmane.org Original-Received: from antah.skarnet.org ([212.85.147.14]) by lo.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1Oll5a-0006Ez-OV for gcsg-supervision@lo.gmane.org; Wed, 18 Aug 2010 18:02:06 +0200 Original-Received: (qmail 20923 invoked by uid 76); 18 Aug 2010 16:04:11 -0000 Mailing-List: contact supervision-help@list.skarnet.org; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Archive: Original-Received: (qmail 20905 invoked from network); 18 Aug 2010 16:04:11 -0000 In-Reply-To: X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; i686-pc-linux-gnu) Xref: news.gmane.org gmane.comp.sysutils.supervision.general:2035 Archived-At: On Wed, 18 Aug 2010 11:23:41 -0400 (EDT) Charlie Brady wrote: > There are many complications that you probably haven't thought of. What > would runit do if the hangcheck script itself hangs? How might you > compromise the existing functionality of runit by adding this feature? How > many race conditions do you introduce? I understand your thoughts about this, and yes i have thought about this, too. But let's make it clear: This can happen with runit as it is now, also: a weird written run-script or a broken log-script might compromise the existing functionality of runit (if it doesnt, adding a new variant like a hangcheck-script wouldn't do so neither). I mean: what happens currently if one of the services which you're trying to start hangs? I havent tried yet, so i guess only the service which you're trying to start would be compromised - not whole runit. And this wouldn't be the case with my suggestion neither. Last but not Least: it's an optional feature, just like the log stuff - You can use it, you don't need to. If some users feel like using it they know about the risks, if there are really any (as explained above). > IMO you don't need to have this functionality in runit, which is already > doing it's specified task well. You want something else to act as a > service watchdog. You use another tool to do that - for instance, nagios. Probably you're right, though i don't exactly understand your argumentation because: Runit is starting crashed processes (this shouldn't be the job of an Init-System - the job of an init-system is starting processes, not making sure that they're up and running - thats the job of a software-watchdog). BUT: runit is doing exactly this. Runit is taking care that your service is up and running, by restarting it if its crashing - By argueing that "checking whether a service is responding (and thus working) is not the job of runit", you might also argue that "restarting a crashed job is not runit's job". To point it out again: It's just "optionally" for users who'd like such a feature, extending the current functionality of restarting a crashed process - If you, or someone else, feels like "this could hurt my whole system" you don't need to use it. This doesn't make such a feature useless or bad. And back to topic: i didn't wanted to request such a feature, i was just asking whether it would be difficult to implement/possible. Whether developers or users implement something like this, is not up to me :) P.S: i get your mails twice, purpose? :-) Cheers -- Jean-Michel Bruenn