Age Gauge¶
An Age Gauge reports the time in seconds since some event last occurred successfully.
It is a use of a Gauge where the value reported is computed
as now - lastSuccessTimestamp on each reporting interval.
The primary use case is the Time Since Last Success alerting pattern: alert when a periodic job, heartbeat, or freshness signal stops advancing.
Lifecycle¶
Age Gauges are long-lived — once set they continue reporting indefinitely until the
process is restarted or the gauge is explicitly removed. For spectatord-backed clients,
spectatord enforces a per-process limit (default 1000, tunable via --age_gauge_limit)
to prevent leaks. To remove or replace one, use the
SpectatorD admin server.