It would be good to be able to display rate data for gauges in the same manner that we support rate data for counters.
When dealing with something like filesystem usage we may be dealing with large gauge data value that only changes slightly with regards to the other values. Eg I have a 1TB disk but I am generally only adding or deleting content in terms of MBs per minute.
If we were to specify it as a counter metric, then we can easily get the rate data and graph that. But this is not an ever increasing counter, data can be deleted from the disk as well. As such when data is deleted the counter considers that a restart and the rate data at that time is not calculable.
If we could also support rate data for gauges, then this issue is resolved. We can properly specify filesystem usage as a gauge and also be able to graph the rate changes.