Un-incremented counters don't have value 0

When I navigate to my metrics endpoint, some counters don’t have values because they were never incremented. Such a counter is the unknown_failure_total which gets incremented on unhandled exceptions.

I have Prometheus hooked up to Grafana and it keeps alerting me that there’s missing data for some counters. I don’t want to suppress this alert because missing data could also mean that Grafana is not able to reach my Prometheus server.

The HELP and TYPE statements are printed even for un-incremented counters, but their zero value is not. Should a 0 value be printed for counters which have yet to be incremented?

# HELP postgres_upsert_failure_total postgres_upsert_failure_total
# TYPE postgres_upsert_failure_total counter
postgres_upsert_failure_total{environment="production"} 2

# HELP unknown_failure_total cli_unknown_failure_total
# TYPE unknown_failure_total counter

Thanks!

[siimon]

Published in 10.0.1!

[dm3]

With labels present there’s no way to know the label values to display a default zero. However, once you’ve initialized the “child” with the label values by calling the SimpleCollector#labels method, you should see zero as in the no-labels case.