Werk #19126: Fix OTel Sum metric rate computation for delta temporality
| Component | Metrics system | ||
| Title | Fix OTel Sum metric rate computation for delta temporality | ||
| Date | Mar 27, 2026 | ||
| Level | Trivial Change | ||
| Class | Bug Fix | ||
| Compatibility | Incompatible - Manual interaction might be required | ||
| Checkmk versions & editions |
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Previously, when rate computation was enabled for OTel Sum metrics (e.g., with "always" or "monotonic counter" mode), Checkmk assumed cumulative temporality for all Sum metrics. This was incorrect for delta-temporality metrics, where the reported value already represents the change over the reporting period (the interval between start and end timestamp).
Checkmk now checks the temporality of OTel Sum metrics at check time. For delta-temporality metrics, the rate is computed directly from the value and its reporting period, without requiring historical state. For cumulative-temporality metrics, behavior is unchanged.
Because of this change, existing thresholds based on delta values may no longer trigger alerts correctly. If you use OpenTelemetry metrics with "sum" metrics in your Checkmk collector, review and update all thresholds configured in the OpenTelemetry service monitoring rule to reflect the new values.