app/vmselect/promql: use Prometheus-compatible label value formatting for count_values function

app/vmselect/promql/aggr.go

@@ -576,7 +576,7 @@ func aggrFuncCountValues(afa *aggrFuncArg) ([]*timeseries, error) {
 			var dst timeseries
 			dst.CopyFromShallowTimestamps(tss[0])
 			dst.MetricName.RemoveTag(dstLabel)
-			dst.MetricName.AddTag(dstLabel, strconv.FormatFloat(v, 'g', -1, 64))
+			dst.MetricName.AddTag(dstLabel, strconv.FormatFloat(v, 'f', -1, 64))
 			for i := range dst.Values {
 				count := 0
 				for _, ts := range tss {

app/vmselect/promql/exec_test.go

@@ -6672,6 +6672,37 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r1, r2, r3, r4}
 		f(q, resultExpected)
 	})
+	t.Run(`count_values_big_numbers`, func(t *testing.T) {
+		t.Parallel()
+		q := `sort_by_label(
+			count_values("xxx", (alias(772424014, "first"), alias(772424230, "second"))),
+			"xxx"
+		)`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1, 1, 1, 1, 1, 1},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.Tags = []storage.Tag{
+			{
+				Key:   []byte("xxx"),
+				Value: []byte("772424014"),
+			},
+		}
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1, 1, 1, 1, 1, 1},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.Tags = []storage.Tag{
+			{
+				Key:   []byte("xxx"),
+				Value: []byte("772424230"),
+			},
+		}
+		resultExpected := []netstorage.Result{r1, r2}
+		f(q, resultExpected)
+	})
 	t.Run(`count_values`, func(t *testing.T) {
 		t.Parallel()
 		q := `count_values("xxx", label_set(10, "foo", "bar") or label_set(time()/100, "foo", "bar", "baz", "xx"))`

docs/CHANGELOG.md

@@ -20,6 +20,7 @@ sort: 15
 * BUGFIX: properly handle queries with multiple filters matching empty labels such as `metric{label1=~"foo|",label2="bar|"}`. This filter must match the following series: `metric`, `metric{label1="foo"}`, `metric{label2="bar"}` and `metric{label1="foo",label2="bar"}`. Previously it was matching only `metric{label1="foo",label2="bar"}`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1601).
 * BUGFIX: vmselect: reset connection timeouts after each request to `vmstorage`. This should prevent from `cannot read data in 0.000 seconds: unexpected EOF` warning in logs. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1562). Thanks to @mxlxm .
 * BUGFIX: keep metric name for time series returned from [rollup_candlestick](https://docs.victoriametrics.com/MetricsQL.html#rollup_candlestick) function, since the returned series don't change the meaning of the original series. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1600).
+* BUGFIX: use Prometheus-compatible label value formatting for [count_values](https://docs.victoriametrics.com/MetricsQL.html#count_values) function. Previously big values could be improperly formatted, which could break query results, which rely on label value such as `... on(label) count_values("label", ...)`.
 * BUGFIX: vmagent: properly use `https` scheme for wildcard TLS certificates for `role: ingress` targets in Kubernetes service discovery. See [this issue](https://github.com/prometheus/prometheus/issues/8902).
 * BUGFIX: vmagent: support host networking mode for `docker_sd_config`. See [this issue](https://github.com/prometheus/prometheus/issues/9116).