Werk #19127: OTel metrics: rate computation no longer applies to histogram types
| Component | Checks & agents | ||||||
| Title | OTel metrics: rate computation no longer applies to histogram types | ||||||
| Date | Mar 27, 2026 | ||||||
| Level | Trivial Change | ||||||
| Class | Bug Fix | ||||||
| Compatibility | Incompatible - Manual interaction might be required | ||||||
| Checkmk versions & editions |
|
Histogram and exponential histogram metrics in the OpenTelemetry check plugin now always report the average of observed values within an interval, regardless of the rate computation setting.
Previously, if you configured "Always compute the rate" in the OpenTelemetry rule, histogram metrics would have a rate (i.e. rate-of-change) applied on top of their already-computed average — effectively measuring acceleration rather than the average itself, which is not meaningful.
What changed
The "Always compute the rate" option is renamed to "Always compute the rate (excluding histograms)". Histogram and exponential histogram data points always report:
- Delta temporality:
sum / count— the average of observed values in the reporting interval - Cumulative temporality:
(delta sum) / (delta count)— the average of new observations since the last check cycle
Migration
If you have "Always compute the rate" configured in any OpenTelemetry rules, review your histogram-type metrics after upgrading. Their reported values will change from a rate-of-the-average to the average itself. Adjust any thresholds set for histogram metrics accordingly.