On Sun, 30 Jun 2013 00:21:51 -0600 Bob Proulx <b...@proulx.com> wrote:
> > I'm running a Cluster that has to be set in Maintenance-Mode if > > monitored services are restarted. Hi Bob, > I assume from this that services are being monitored. If they are > restarted and during the restart the monitoring detects that the > service is offline then it triggers an alert. And whatever the First it will try to restart the service, if this fails the service will be migrated to another node. > setting of "Maintenance-Mode" does basically tells the monitoring to > ignore any problem for that time period. Is that about right? Yes. But it will disable the monitor for all services on all nodes, which isn't always needed. > I see the problem for you now. Because various packages such as > phpmyadmin will run the restarts in the postinst scripts. Therefore > in order to really determine what would be restarted it would be > necessary to walk through the postinst scripts. And that is an open > ended basically practically impossible problem. Correct. > > At the moment I try out update-rc.d to avoid any service to be > > restarted during upgrade, but I wonder if there might be a better > > solution. > > It's policy-rc.d, of course, not update-rc. > That is an idea. Every use of a postinst script to restart a daemon > should be gated by policy-rc.d. And you could always approve the > restart but that script could at that time put the node into your > maintenance-mode right then. Don't know what you would use to return > it to regular service afterward. Perhaps after a timeout. That is a nice idea, thanks. At the moment policy-rc.d just exit with 101. > Note that I (on this mailing list) learned recently that while > policy-rc.d does gate all uses of postinst it does nothing at boot > time. I think that is a hole in the feature set. During boot time > the daemon is started regardless of any policy-rc.d configuration. That's fine. The init-Scripts for the monitored services are disabled at boot time and the Cluster Resource Manager will start them. I think that policy-rc.d is ignored at boot is more of a feature (at least in some use cases). I'll check out your idea and think it will work quite fine. Thanks again. Best regards Denis Witt -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20130701110419.2f107efe@X200
