[Pacemaker] Enable remote monitoring

[Dejan Muhamedagic]

On Fri, Nov 09, 2012 at 05:22:08PM +0100, Lars Marowsky-Bree wrote:
> On 2012-11-09T14:06:29, Dejan Muhamedagic <dejanmm at fastmail.fm> wrote:
> 
> > > > > Uh? How should this be handled by the RA? Can you elaborate?
> > > > For instance, using expect to wait for the login prompt on the
> > > > console. Or, if that's possible, employing libvirt to get the
> > > > current runlevel. We already discussed this. Your objection was
> > > > that this won't work with the other OS.
> > > Oh. This. No, this is inacceptable.
> > I'm really curious to know why exactly.
> 
> Exactly because of this - the need to parse console output, which is
> very OS specific, and prone to break, and not all services that we
> monitor may show up on the console at all. Getting more reliable metrics
> would require instrumenting the guest (such as understanding the
> runlevel it is at), and that is also a No-No. The idea is to be able to
> run unmodified guests.
> 
> > > And also doesn't really help with getting the state/readiness of
> > > services the guest might provide.
> > Isn't it that one gets a login prompt only once the host reached a
> > certain run level?
> 
> Services may start in the background. The console may either be text,
> graphical, or network only.

Hmm, I have yet to see a Linux/UNIX host without a console. And
that means quite some time ;-)

Thanks,

Dejan

> 
> Regards,
>     Lars
> 
> -- 
> Architect Storage/HA
> SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
> "Experience is the name everyone gives to their mistakes." -- Oscar Wilde
> 
> 
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