fix: handle NaN in scraper (#23944)

* fix: handle NaN values in scraper

* chore: a converted int will never be NaN

gather/prometheus.go

@@ -93,12 +93,20 @@ func (p *prometheusScraper) parse(r io.Reader, header http.Header, target influx
 				// summary metric
 				fields = makeQuantiles(m)
 				fields["count"] = float64(m.GetSummary().GetSampleCount())
-				fields["sum"] = float64(m.GetSummary().GetSampleSum())
+
+				ss := float64(m.GetSummary().GetSampleSum())
+				if !math.IsNaN(ss) {
+					fields["sum"] = ss
+				}
 			case dto.MetricType_HISTOGRAM:
 				// histogram metric
 				fields = makeBuckets(m)
 				fields["count"] = float64(m.GetHistogram().GetSampleCount())
-				fields["sum"] = float64(m.GetHistogram().GetSampleSum())
+
+				ss := float64(m.GetHistogram().GetSampleSum())
+				if !math.IsNaN(ss) {
+					fields["sum"] = ss
+				}
 			default:
 				// standard metric
 				fields = getNameAndValue(m)