Replace gauge value instead of summing (#1)

* Replace gauge value instead of summing
* Disable helm deploy workflow

.github/workflows/on_merge.yaml

@@ -1,9 +1,10 @@
 name: continuous deploy
 
 on:
-  push:
-    branches:
-      - main
+  workflow_dispatch:
+  # push:
+  #   branches:
+  #     - main
 
 jobs:
   release-charts:

README.md

@@ -4,7 +4,7 @@ Prometheus Aggregation Gateway is a push gateway that aggregates metrics for Pro
 
 * Counters where all labels match are added up.
 * Histograms are added up; if bucket boundaries are mismatched then the result has the union of all buckets and counts are given to the lowest bucket that fits.
-* Gauges are also added up (but this may not make any sense)
+* Gauges are replaced
 * Summaries are treated as a pair of counters (quantile information is discarded if present).
 
 ## How to use

metrics/merge.go

@@ -82,13 +82,10 @@ func mergeMetric(ty dto.MetricType, a, b *dto.Metric) *dto.Metric {
 		}
 
 	case dto.MetricType_GAUGE:
-		// No very meaningful way for us to merge gauges.  We'll sum them
-		// and clear out any gauges on scrape, as a best approximation, but
-		// this relies on client pushing with the same interval as we scrape.
 		return &dto.Metric{
 			Label: a.Label,
 			Gauge: &dto.Gauge{
-				Value: float64ptr(*a.Gauge.Value + *b.Gauge.Value),
+				Value: float64ptr(*b.Gauge.Value),
 			},
 		}