Currently each time the JsonMetadataService saves metadata, it posts it to SolarNetwork. For some high-frequency data sources, that would result in too many updates. For example a Virtual Meter Filter defined on a data source collecting data every 0.5s would post data twice/second, which is far too much.

The metadata is already cached in SolarNode and that cache is backed up with SolarNode backups, so it seems safe to add some throttle settings so the frequency of updating the metadata on SolarNetwork can be tuned. At a basic level it might be easiest to only have one setting for all metadata; a more complex implementation might allow settings per source ID.