01
Freshness
Catches a table that has stopped receiving data when it normally would.
- What it learns
- How far behind the newest row usually is at the end of each day, as a median, a 90th percentile and a worst case, along with how often the table actually loads.
- When it flags
- When the newest row is more than a day older than the usual 90th-percentile lag, or six hours past the worst lag ever seen, on a weekday the table normally loads. A table that suddenly has no timestamps at all is flagged too.
- What the agent does
- Measures the lag itself and looks at recent row counts by day to tell "not scheduled today" apart from "stale".
- What it leaves alone
- Weekly and weekday-only tables on their quiet days. A table with no timestamp column is not given a freshness check.