Nagios vs Juju monitoring

[Marco Ceppi]

That's an interesting bug(?). Looking at the hooks, it appears the same
hook for relation-departed is the one registered with relation-broken.
I'm not sure of the workflow in Juju with regards to "machine manually
removed" but odds are it triggers a relation-broken (as in an unclean
departure) which results in Nagios charm removing the relation as if
remove-relation command was run. Since I'm not exactly sure of the charm
relation workflow (for instances does a destroy-service also fire a
relation-broken event, or does it use the "cleaner" relation-departed
event), but that might be one place to start investigating.

Thanks,
Marco Ceppi

On 11/23/2012 09:38 AM, Thomas Leonard wrote:
> Hi guys,
>
> We're trying to use Juju to set up a nagios service to monitor various
> other Juju-deployed services. We deployed nagios and some services and
> added relations between them. Nagios showed all the hosts in green. Good.
>
> Then, to test it, we paused one of the service VMs. We were hoping
> that nagios would show the failed service in red and send a warning
> notification.
>
> Instead, the service simply disappeared from the nagios display. It
> looks like Juju detected that the machine wasn't available and removed
> the relation.
>
> We unpaused the machine and then manually restarted juju-machine-agent
> on it and it reappeared in nagios.
>
> It seems like this behaviour isn't very useful; it is intentional?
>
>