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From: Gerrit Pape <pape@smarden.org>
Subject: Re: runit under sysvinit - coping when runsvdir dies
Date: Thu, 17 Nov 2005 09:08:51 +0000	[thread overview]
Message-ID: <20051117090319.29817.qmail@f69151e2a0a700.315fe32.mid.smarden.org> (raw)
In-Reply-To: <dlajh8$eqj$1@sea.gmane.org>

On Mon, Nov 14, 2005 at 12:03:20PM -0600, Charles Duffy wrote:
> I recently had a situation on a fielded server where runsvdir (from 
> runit 1.2.3) apparently died; in any event, all the runsv processes 
> which would typically be directly under runsvdir were instead inherited 
> by sysvinit and running there. However, since runsvdir was respawned by 
> sysvinit, a great deal of CPU time was being spent continuously trying 
> to start new runsv instances under the fresh runsvdir -- attempts which 
> failed because there were still runsv instances alive and holding open 
> the relevant locks. I killed the old runsv instances with "runsvctrl e", 
> and fresh children of the new runsvdir took their place -- but there are 
> still some questions raised:
> 
> - How could this have happened? The system's message log doesn't show 
> the OOM killer taking down runsvdir or any segfault on the part of the same.

Charlie answered that.

> - How could such situations be more gracefully handled in the future? 
> Having the customer call and complain because their server was unusably 
> slow was a less-than-ideal way to find out about this issue.

If runsvdir receives the HUP signal, it sends a term signal to all runsv
processes it manages.  On the TERM signal, it simply exits, leaving the
runsv processes alone.  Maybe I should switch that, so that TERM signals
'by mistake' are handled better.  It then would re-init the complete
system, stopping all services plus supervisors on TERM, and starting
them up again after being re-spawned through inittab.

I'm not yet sure about side-effects of this change though.

Regards, Gerrit.


  parent reply	other threads:[~2005-11-17  9:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-11-14 18:03 Charles Duffy
2005-11-16  3:50 ` Charlie Brady
2005-11-17  9:08 ` Gerrit Pape [this message]
2005-11-17 11:13   ` Charles Duffy

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