We previously removed the data point tagging feature in HWKMETRICS-253 because it was not really used and because I had some concerns about the overall design. Both Hawkular BTM and APIMan have expressed a desire to have this feature added back. I want to limit the scope of this as compared to the original design at least for now until we have further requirements/requests.
We need to add a tags column,
The previous implementation had an index table for storing tagged data points. We are not adding back any kind of index right now.
The tags will have the same key/value format as the metric-level tags. The DataPoint class should be updated to include an immutable tags field/property.
We only want to allow tags to be added when inserting data. There will be no support for updating tags of existing data points as was the case with the previous implementation.
The REST API needs to be updated to add support for fetching/writing tags. If a data point does not have any tags, then the tags field should be excluded from the JSON output as we do with other collections.
Lastly, we will need to update docs, but a separate docs bug might be better for that.