Viewing newly added metrics requires restart about tgres HOT 1 OPEN

I think that's entirely possible, especially if you do not hit the /metrics endpoint, which is what will cause the cache to refresh when something is not found.

The HTTP interface hits the database directly, it has no connection with the code that is responsible for receiving data points and storing them in the database. And so it's possible that series/datapoints exist, and yet the HTTP interface doesn't know about them yet.

IIRC tgres used to refresh the UI name cache periodically, but I may have disabled that because when you have a lot of series, it doesn't work very well. What it presently does is refresh after calls to '/metrics'.

The right way to do this would be to listen for notifications from Postgres that a new series was created, there's even a comment left to that extent: https://github.com/tgres/tgres/blob/master/dsl/named_ds.go#L125

from tgres.