The "Database size" stat had no thresholds, so Grafana applied its stat
default (green base, red at >=80). The query is pg_database_size_bytes, so a
healthy ~9 MiB database (9.4M >> 80) rendered permanently RED on the
Scrabble - Resources dashboard (test + prod), reading as a false alert; the
neighbouring percentunit cache-hit stat stayed green only because its 0..1
values fall under 80.
Add absolute byte thresholds sized to the 40 GiB prod disk (4.6 GiB used,
observability bounded -- Tempo <=1 GiB, Prometheus 7d -- so the DB is the
only unbounded grower): green up to 8 GiB, yellow at 8 GiB (~20% of disk),
red at 16 GiB (~40%), an early warning with ample runway before the disk
tightens, not a panic line. Cosmetic panel coloring only; there are no
Grafana alert rules provisioned.
Ilia Denisov