Nodata to Zero values query

Topic: Handling Missing HAProxy Logs in Prometheus Across Multiple Clusters


I’m currently working on monitoring HAProxy logs using Loki and Prometheus. I’ve created a recording rule in Loki to count the logs:

Loki Query:

sum by (hostname, k8s_cluster_name) (count_over_time({hostname=~".*haproxy.*"} |= "" | json [5m]))

This query aggregates the log counts over 5-minute intervals, grouped by hostname and k8s_cluster_name.

Prometheus Query:


This PromQL query calculates the average number of HAProxy logs over a 15-minute window.


I want to handle scenarios where logs are not received for a particular cluster, and these missing logs should be represented as zero values in Prometheus. I found the absent function in Prometheus, which converts “no data” to zero values. However, the absent function only works for single clusters, not across multiple clusters.


How can I create a Prometheus query that handles missing HAProxy logs and shows zero values across multiple clusters?

I would appreciate any insights or suggestions on this topic. Thank you!