[Pkg-monitoring-maintainers] Bug#731137: support for new metrics that appear at runtime

[Daniel Pocock]

Package: ganglia-monitor
Version: 3.6.0-1
Severity: wishlist
Tags: upstream

Currently, the gmond agent discovers all metrics when it starts and then
starts sending values for those metrics.

Consider the filesystem metric module:

- new filesystems may be mounted while gmond is running.  gmond will not
notice them until somebody restarts gmond.

- a filesystem is unmounted while gmond is running.  The module or gmond
may behave badly when the filesystem disappears or continue sending the
last free space metric from before the unmount.  The Ganglia graph gives
no definite information that the filesystem was unmounted.

The agent (and potentially some of the modules) need to be improved to
support these runtime changes automatically and reliably.