I often encounter the need to define multiple items on the same host with the same key. This is currently unsupported, for good reason, as keys are used to uniquely identify an item.

it is needed however, to monitor point-in-time samples along side deltas.

An example use case is to track both the used disk space of a volume and the rate at which is consumed. Both would use the key vfs.fs.size[fs,used], but the first would store an integer value, while the second would store a delta.

This also appears for database growth, service request counts vs. request rate, etc.