How to group and stream the specific set of metrics over remote-write?

[tejaswini vadlamudi]

Hi,

I have a use case in mind, a remote write receiver has no interest in collecting metrics exposed by a target.

How can we stream a specific set of metrics to such receivers?

I'm listing down some possibilities, could you add/correct if I am thinking wrong?

1. Add label "kpi" label with the value true to metrics that are of interest in the instrumentation and add a remote-write relabeling rule to pass only these metrics 
2.  Add relabel filters in remote-write config to drop unwanted metrics by labels or names
3. Add relabel filters in remote-write config to pass metrics that are of interest based on name/label
4. Place label or metric filters in the remote receiver end instead

Do we know the impact of relabeling rules and actions on Prometheus performance?

Thanks,

Teja