"_total" suffix missing from counter metrics with older Prometheus clients

[eero-t]

When using python3-prometheus-client in OpenSuse 15.4 (that corresponds to SLES 15.4), XPUM counter metrics are missing _total suffix required by the OpenMetrics spec: https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md

XPUM should not rely on (newer) prometheus-client adding the required suffix, but directly use correct metric names.

PS. While OpenSuse prometheus client is very old v0.0.20 (from 2017), _total suffix enforcement is more recent feature. I.e. this bug will manifest also with never client versions than that.

[eero-t]

I.e. this bug will manifest also with never client versions than that.

Reading Prometheus Python client release history, "_total" suffix enforcement seems to have come already in 0.4.0 (released in 2018).

And OpenSuse 15.4 has also v0.7.1 (released in 2019) of that package, named as python3-prometheus_client.

Using that package (instead python3-prometheus-client), adds the required _total suffixes, so this bug can be considered very low priority.