How to check if an alert is inactive?

[zxwing]

The document says:

    For pending and firing alerts, Prometheus also stores synthetic time series of the form 
    ALERTS{alertname="<alert name>", alertstate="pending|firing", <additional alert labels>}. The 
    sample value is set to 1 as long as the alert is in the indicated active (pending or firing) state, and a 
    single 0 value gets written out when an alert transitions from active to inactive state. Once inactive, 
    the time series does not get further updates.

but I am confused by what I observed. After an alert turns to inactive (the Alerts page becomes green and shows 0 active), querying ALERTS metric still returns data with state pending/firing, value 0/1 for a while, and finally returns no data which means the alert becomes inactive.

What is the reliable programming way to judge if an alert is inactive?

[brian-brazil]

Usage questions are best asked at https://groups.google.com/forum/#!forum/prometheus-users

[lock]

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