om2/gaugehistogram: prohibit negative count and bucket values

.github/workflows/openmetrics.yml

@@ -25,6 +25,9 @@ jobs:
       run: |
         python3 openmetrics-spec-tests/check_openmetrics_spec.py docs/specs/om/open_metrics_spec_2_0.md
     - name: Check version bump for OpenMetrics 2.0
+      # Feature branches collect multiple spec changes under a single version,
+      # the bump is only required once the work is merged into main.
+      if: github.event.pull_request.base.ref == 'main'
       env:
         BASE_REF: ${{ github.event.pull_request.base.ref }}
         HEAD_SHA: ${{ github.event.pull_request.head.sha }}

MAINTAINERS.md

@@ -15,3 +15,4 @@ following maintainers with their focus areas:
   generator.
 * Richard Hartmann <richih@richih.org> @RichiH: Everything
   else.
+* Jan Fajerski <prometheus@fajerski.name> @jan--f

docs/instrumenting/exporters.md

@@ -84,6 +84,7 @@ wide variety of JVM-based applications, for example [Kafka](http://kafka.apache.
    * [ProSAFE exporter](https://github.com/dalance/prosafe_exporter)
    * [Redfish exporter](https://github.com/comcast/fishymetrics)
    * [SmartRAID exporter](https://gitlab.com/calestyo/prometheus-smartraid-exporter)
+   * [TEMPer USB thermal sensor exporter](https://github.com/BAPostma/temper-exporter)
    * [Waveplus Radon Sensor Exporter](https://github.com/jeremybz/waveplus_exporter)
    * [Weathergoose Climate Monitor Exporter](https://github.com/branttaylor/watchdog-prometheus-exporter)
    * [Windows exporter](https://github.com/prometheus-community/windows_exporter)

docs/specs/om/open_metrics_spec_2_0.md

@@ -339,19 +339,19 @@ GaugeHistograms measure current distributions. Common examples are how long item
 
 A GaugeHistogram Sample MUST contain Gcount, Gsum values.
 
-The Gcount value MUST be equal to the number of measurements currently in the GaugeHistogram. The Gcount is a gauge semantically. The Gcount SHOULD be an integer. The Gcount SHOULD NOT be -Inf, +Inf, NAN, or negative.
+The Gcount value MUST be equal to the number of measurements currently in the GaugeHistogram. The Gcount is a gauge semantically. The Gcount SHOULD be an integer. The Gcount MUST NOT be negative. The Gcount SHOULD NOT be +Inf, NaN.
 
-Float and negative Gcount is allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
+Float Gcount is allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
 
 The Gsum value MUST be equal to the sum of all the measured values currently in the GaugeHistogram. The Gsum is a gauge semantically.
 
 A GaugeHistogram MUST measure values that are not NaN in either [Classic Buckets](#classic-buckets) or [Native Buckets](#native-buckets) or both. Measuring NaN is different for Classic and Native Buckets, see in their respective sections.
 
 If a GaugeHistogram stops measuring values in either Classic or Native Buckets and keeps measuring values in the other, it MUST clear and not expose the buckets it stopped measuring into. This avoids exposing different distribution from the two kind of buckets at the same time.
 
-Every Bucket MUST have well-defined boundaries and a value. Boundaries of a Bucket MUST NOT be NaN. Bucket values SHOULD be integers. Semantically, bucket values are gauges and SHOULD NOT be -Inf, +Inf, NaN, or negative.
+Every Bucket MUST have well-defined boundaries and a value. Boundaries of a Bucket MUST NOT be NaN. Bucket values are gauges semantically. Bucket values SHOULD be integers. Bucket values MUST NOT be negative. Bucket values SHOULD NOT be +Inf, NaN.
 
-Float and negative bucket values are allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
+Float bucket values are allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
 
 A GaugeHistogram SHOULD NOT include NaN measurements. If a GaugeHistogram includes NaN measurements, then NaN measurements MUST be counted in the Gcount and the Gsum MUST be NaN.