I'm trying to create some simple alerts when specific metrics drop to 0, to catch cases where tracking has broken for some reason.
I would expect to be able to do this with the "is below or equals" operator, but for some reason the preview states it would create a false positive every week. So how to achieve this?
I've also tried to achieve this with "Anomaly is below expected" set to 99.9% threshold, which I would expect to be precise enough to catch cases where a metric drops to 0 or near 0. But that already gives an alert where the anomaly is 40% below expected, which is way too sensitive. How to understand the relationship between threshold and anomaly percentage?