HumioExporter crashes if aggregated query contains no rows

[srindal]

A Humio query that ends with a count() will produce 0 if no rows were found, but a query that ends with an avg() or a sum() will produce no result if no rows were found. The latter will cause the humioexporter to crash. I suggest that the exporter either returns a zero, or removes the metric from the list of metrics until the query starts producing data.

[Crevil]

I'm unable to reproduce this case.

The following query produces a 0 metric as expected. Can you share a crash log or alike from the latest version?

queries:
  - query: nothing=existing | sum(status)
    repo: humio
    interval: 1m
    metric_name: humio_status_sum

[srindal]

Hi, we are running with a locally modified HumioExporter to mitigate this issue. I have these log statements coming in regularly:
time="2022-08-05T10:51:11Z" level=info msg="Replace null value with 0 for #P12-i5sxxICINzcJfX0saYAtKrjZ" source="main.go:192"

This is the fix, and it works well for us. Without this fix we had plenty of crashes. I can try to run with the latest version of the Exporter and verify if I still see the problem. Btw did you try with an avg-function?

			floatValue := 0.0
			for _, f := range supportedFunctions {
				if (len(poll.Events) > 0) {
					value, ok := poll.Events[0][f]
					if !ok {
						continue
					}
					floatValue, err = parseFloat(value)
					if err != nil {
						done <- err
						return
					}
					break
				} else {
					log.Infof("Replace null value with 0 for #%v", job.Id)
				}
			}