app/vmselect/promql: add drop_common_labels() function

app/vmselect/promql/exec_test.go

@@ -1832,6 +1832,65 @@ func TestExecSuccess(t *testing.T) {
 		resultExpected := []netstorage.Result{r}
 		f(q, resultExpected)
 	})
+	t.Run(`drop_common_labels(single_series)`, func(t *testing.T) {
+		t.Parallel()
+		q := `drop_common_labels(label_set(time(), "foo", "bar", "__name__", "xxx", "q", "we"))`
+		r := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		resultExpected := []netstorage.Result{r}
+		f(q, resultExpected)
+	})
+	t.Run(`drop_common_labels(multi_series)`, func(t *testing.T) {
+		t.Parallel()
+		q := `drop_common_labels((
+			label_set(time(), "foo", "bar", "__name__", "xxx", "q", "we"),
+			label_set(time()/10, "foo", "bar", "__name__", "yyy"),
+		))`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		r1.MetricName.MetricGroup = []byte("xxx")
+		r1.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("q"),
+			Value: []byte("we"),
+		}}
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{100, 120, 140, 160, 180, 200},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.MetricGroup = []byte("yyy")
+		resultExpected := []netstorage.Result{r1, r2}
+		f(q, resultExpected)
+	})
+	t.Run(`drop_common_labels(multi_args)`, func(t *testing.T) {
+		t.Parallel()
+		q := `drop_common_labels(
+			label_set(time(), "foo", "bar", "__name__", "xxx", "q", "we"),
+			label_set(time()/10, "foo", "bar", "__name__", "xxx"),
+		)`
+		r1 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{100, 120, 140, 160, 180, 200},
+			Timestamps: timestampsExpected,
+		}
+		r2 := netstorage.Result{
+			MetricName: metricNameExpected,
+			Values:     []float64{1000, 1200, 1400, 1600, 1800, 2000},
+			Timestamps: timestampsExpected,
+		}
+		r2.MetricName.Tags = []storage.Tag{{
+			Key:   []byte("q"),
+			Value: []byte("we"),
+		}}
+		resultExpected := []netstorage.Result{r1, r2}
+		f(q, resultExpected)
+	})
 	t.Run(`label_keep(nolabels)`, func(t *testing.T) {
 		t.Parallel()
 		q := `label_keep(time(), "foo", "bar")`

app/vmselect/promql/transform.go

@@ -42,6 +42,7 @@ var transformFuncs = map[string]transformFunc{
 	"day_of_week":          newTransformFuncDateTime(transformDayOfWeek),
 	"days_in_month":        newTransformFuncDateTime(transformDaysInMonth),
 	"deg":                  newTransformFuncOneArg(transformDeg),
+	"drop_common_labels":   transformDropCommonLabels,
 	"end":                  newTransformFuncZeroArgs(transformEnd),
 	"exp":                  newTransformFuncOneArg(transformExp),
 	"floor":                newTransformFuncOneArg(transformFloor),
@@ -1486,6 +1487,43 @@ func transformLabelMap(tfa *transformFuncArg) ([]*timeseries, error) {
 	return rvs, nil
 }
 
+func transformDropCommonLabels(tfa *transformFuncArg) ([]*timeseries, error) {
+	args := tfa.args
+	if len(args) < 1 {
+		return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 1)
+	}
+	rvs := args[0]
+	for _, tss := range args[1:] {
+		rvs = append(rvs, tss...)
+	}
+	m := make(map[string]map[string]int)
+	countLabel := func(name, value string) {
+		x := m[name]
+		if x == nil {
+			x = make(map[string]int)
+			m[name] = x
+		}
+		x[value]++
+	}
+	for _, ts := range rvs {
+		countLabel("__name__", string(ts.MetricName.MetricGroup))
+		for _, tag := range ts.MetricName.Tags {
+			countLabel(string(tag.Key), string(tag.Value))
+		}
+	}
+	for labelName, x := range m {
+		for _, count := range x {
+			if count != len(rvs) {
+				continue
+			}
+			for _, ts := range rvs {
+				ts.MetricName.RemoveTag(labelName)
+			}
+		}
+	}
+	return rvs, nil
+}
+
 func transformLabelCopy(tfa *transformFuncArg) ([]*timeseries, error) {
 	return transformLabelCopyExt(tfa, false)
 }

docs/CHANGELOG.md

@@ -23,6 +23,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 * FEATURE: allow specifying TLS cipher suites for mTLS connections between cluster components via `-cluster.tlsCipherSuites` command-line flag. See [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#mtls-protection).
 * FEATURE: [vmui](https://docs.victoriametrics.com/#vmui): shown an empty graph on the selected time range when there is no data on it. Previously `No data to show` placeholder was shown instead of the graph in this case. This prevented from zooming and scrolling of such a graph.
 * FEATURE: expose `vm_indexdb_items_added_total` and `vm_indexdb_items_added_size_bytes_total` counters at `/metrics` page, which can be used for monitoring the rate for addition of new entries in `indexdb` (aka `inverted index`) alongside the total size in bytes for the added entries. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2471).
+* FEATURE: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): add `drop_common_labels()` function, which drops common `label="name"` pairs from the passed time series. See [these docs](https://docs.victoriametrics.com/MetricsQL.html#drop_common_labels).
 
 * BUGFIX: [vmctl](https://docs.victoriametrics.com/vmctl.html): return non-zero exit code on error. This allows handling `vmctl` errors in shell scripts. Previously `vmctl` was returning 0 exit code on error. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2322).
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): properly show `scrape_timeout` and `scrape_interval` options at `http://vmagent:8429/config` page. Previously these options weren't displayed even if they were set in `-promscrape.config`.

docs/MetricsQL.md

@@ -713,6 +713,11 @@ See also [implicit query conversions](#implicit-query-conversions).
 
 `alias(q, "name")` sets the given `name` to all the time series returned by `q`. For example, `alias(up, "foobar")` would rename `up` series to `foobar` series.
 
+
+#### drop_common_labels
+
+`drop_common_labels(q1, ...., qN)` drops common `label="value"` paris among time series returned from `q1, ..., qN`.
+
 #### label_copy
 
 `label_copy(q, "src_label1", "dst_label1", ..., "src_labelN", "dst_labelN")` copies label values from `src_label*` to `dst_label*` for all the time series returned by `q`. If `src_label` is empty, then the corresponding `dst_label` is left untouched.

go.mod

@@ -10,7 +10,7 @@ require (
 	// like https://github.com/valyala/fasthttp/commit/996610f021ff45fdc98c2ce7884d5fa4e7f9199b
 	github.com/VictoriaMetrics/fasthttp v1.1.0
 	github.com/VictoriaMetrics/metrics v1.18.1
-	github.com/VictoriaMetrics/metricsql v0.41.0
+	github.com/VictoriaMetrics/metricsql v0.42.0
 	github.com/aws/aws-sdk-go v1.43.41
 	github.com/cespare/xxhash/v2 v2.1.2
 	github.com/cheggaaa/pb/v3 v3.0.8

go.sum

@@ -117,8 +117,8 @@ github.com/VictoriaMetrics/fasthttp v1.1.0 h1:3crd4YWHsMwu60GUXRH6OstowiFvqrwS4a
 github.com/VictoriaMetrics/fasthttp v1.1.0/go.mod h1:/7DMcogqd+aaD3G3Hg5kFgoFwlR2uydjiWvoLp5ZTqQ=
 github.com/VictoriaMetrics/metrics v1.18.1 h1:OZ0+kTTto8oPfHnVAnTOoyl0XlRhRkoQrD2n2cOuRw0=
 github.com/VictoriaMetrics/metrics v1.18.1/go.mod h1:ArjwVz7WpgpegX/JpB0zpNF2h2232kErkEnzH1sxMmA=
-github.com/VictoriaMetrics/metricsql v0.41.0 h1:fhWnSE9ZXVEbiXXGFY73YPLdovTaDRaDaFdxC3TTRZs=
-github.com/VictoriaMetrics/metricsql v0.41.0/go.mod h1:6pP1ZeLVJHqJrHlF6Ij3gmpQIznSsgktEcZgsAWYel0=
+github.com/VictoriaMetrics/metricsql v0.42.0 h1:E+NZWdpZHSLapQTuT9g+MB4vvD9JB6dSd/0L8QDkcQ4=
+github.com/VictoriaMetrics/metricsql v0.42.0/go.mod h1:6pP1ZeLVJHqJrHlF6Ij3gmpQIznSsgktEcZgsAWYel0=
 github.com/VividCortex/ewma v1.1.1/go.mod h1:2Tkkvm3sRDVXaiyucHiACn4cqf7DpdyLvmxzcbUokwA=
 github.com/VividCortex/ewma v1.2.0 h1:f58SaIzcDXrSy3kWaHNvuJgJ3Nmz59Zji6XoJR/q1ow=
 github.com/VividCortex/ewma v1.2.0/go.mod h1:nz4BbCtbLyFDeC9SUHbtcT5644juEuWfUAUnGx7j5l4=

vendor/github.com/VictoriaMetrics/metricsql/optimizer.go

@@ -403,7 +403,7 @@ func getTransformArgIdxForOptimization(funcName string, args []Expr) int {
 
 func isLabelManipulationFunc(funcName string) bool {
 	switch strings.ToLower(funcName) {
-	case "alias", "label_copy", "label_del", "label_graphite_group", "label_join", "label_keep", "label_lowercase",
+	case "alias", "drop_common_labels", "label_copy", "label_del", "label_graphite_group", "label_join", "label_keep", "label_lowercase",
 		"label_map", "label_match", "label_mismatch", "label_move", "label_replace", "label_set", "label_transform",
 		"label_uppercase", "label_value":
 		return true

vendor/github.com/VictoriaMetrics/metricsql/transform.go

@@ -28,6 +28,7 @@ var transformFuncs = map[string]bool{
 	"day_of_week":          true,
 	"days_in_month":        true,
 	"deg":                  true,
+	"drop_common_labels":   true,
 	"end":                  true,
 	"exp":                  true,
 	"floor":                true,

vendor/modules.txt

@@ -27,7 +27,7 @@ github.com/VictoriaMetrics/fasthttp/stackless
 # github.com/VictoriaMetrics/metrics v1.18.1
 ## explicit; go 1.12
 github.com/VictoriaMetrics/metrics
-# github.com/VictoriaMetrics/metricsql v0.41.0
+# github.com/VictoriaMetrics/metricsql v0.42.0
 ## explicit; go 1.13
 github.com/VictoriaMetrics/metricsql
 github.com/VictoriaMetrics/metricsql/binaryop