monitoring: allow NaN values in alert queries by default
Created by: bobheadxi
Many alert queries divide-by-0 in normal situations, such as low-traffic instances and scenarios, causing many alerts to require DataMayBeNaN
to be true. This change switches our default to allow NaN values without triggering alerts.
There are currently 44 instances of alerts with DataMayBeNan: true
many of them ratio alerts, and possibly more require it: https://github.com/sourcegraph/sourcegraph/issues/14401 was due to histogram_quantile
returning NaN on no data, and it seems that all histogram_quantile
alerts are susceptible to this (1, 2) and require DataMayBeNaN
(there are 23 alerts using histogram_quantile
), so at this point might as well switch the defaults around
Closes https://github.com/sourcegraph/sourcegraph/issues/10689