Raise alert on same measurement but different tags

[AlexGrs]

Description
I have a measurement which looks like this:

name: test
tags: status = (ok | nok)
field: number (int)

I need to raise an alert when the failure rate nok / (ok+nok) is > Z%
.

I first tried with batch using the following syntax:

var influx_query = 'SELECT count(number) AS count from "test"."autogen"."test"'
status=\'failed\''
var total_failed_query = 'SELECT count(number) AS failed_count from "test"."autogen"."test" WHERE status=\'failed\''

var total = batch
  |query(influx_query)
    .period(5m)
    .every(1m)
    .fill('none')

var failed = batch
  |query(total_failed_query)
    .period(period)
    .every(every)
    .fill(0)

failed
  |join(total)
    .as('failed','success')
    .tolerance(5m)
    .fill(0)
 |eval(lambda: "failed.failed_count" / "total.count")
   .as('failure_rate')
|alert()
  .id('kapacitor_test')
  .warn(...)

The thing is, when the query 2 is executed, it happens there are no point with status at failed . Due to this influxdb issue, fill(0) returns no points causing the join() to never be evaluated.

As a result, if I was in warning mode and all new point have status at success I will never go back in normal level because the join() will not be triggered.

Do you have any recommendations to solve this kind of problem ? Is it possible to perform it in one query using groupBy ? (I tried also but failed as there is still no point for the failed tag).

Thanks.