Merge pull request #22590 from karalabe/nil-histogram

metrics/influxdb: don't push empty histograms, no measurement != 0

metrics/influxdb/influxdb.go

@@ -162,6 +162,8 @@ func (r *reporter) send() error {
 			})
 		case metrics.Histogram:
 			ms := metric.Snapshot()
+
+			if ms.Count() > 0 {
 				ps := ms.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999, 0.9999})
 				pts = append(pts, client.Point{
 					Measurement: fmt.Sprintf("%s%s.histogram", namespace, name),
@@ -182,6 +184,7 @@ func (r *reporter) send() error {
 					},
 					Time: now,
 				})
+			}
 		case metrics.Meter:
 			ms := metric.Snapshot()
 			pts = append(pts, client.Point{