app/vmselect: initial implementation of Graphite Metrics API

See https://graphite-api.readthedocs.io/en/latest/api.html#the-metrics-api
2024-11-23 12:31:07 +01:00 · 2020-09-11 00:28:19 +03:00 · 2020-09-11 00:28:19 +03:00 · f6bc608e86
commit f6bc608e86
parent 3eccecd5fd
20 changed files with 1706 additions and 225 deletions
--- a/README.md
+++ b/README.md
@ -103,6 +103,8 @@ See [features available for enterprise customers](https://github.com/VictoriaMet
 * [How to import data in Prometheus exposition format](#how-to-import-data-in-prometheus-exposition-format)
 * [How to import CSV data](#how-to-import-csv-data)
 * [Prometheus querying API usage](#prometheus-querying-api-usage)
+  * [Prometheus querying API enhancements](#prometheus-querying-api-enhancements)
+* [Graphite Metrics API usage](#graphite-metrics-api-usage)
 * [How to build from sources](#how-to-build-from-sources)
  * [Development build](#development-build)
  * [Production build](#production-build)
@ -392,9 +394,11 @@ The `/api/v1/export` endpoint should return the following response:

 ### Querying Graphite data

-Data sent to VictoriaMetrics via `Graphite plaintext protocol` may be read either via
-[Prometheus querying API](#prometheus-querying-api-usage)
-or via [go-graphite/carbonapi](https://github.com/go-graphite/carbonapi/blob/master/cmd/carbonapi/carbonapi.example.prometheus.yaml).
+Data sent to VictoriaMetrics via `Graphite plaintext protocol` may be read via the following APIs:
+
+* [Prometheus querying API](#prometheus-querying-api-usage)
+* Metric names can be explored via [Graphite metrics API](#graphite-metrics-api-usage)
+* [go-graphite/carbonapi](https://github.com/go-graphite/carbonapi/blob/master/cmd/carbonapi/carbonapi.example.prometheus.yaml)

 ### How to send data from OpenTSDB-compatible agents

@ -585,6 +589,21 @@ Additionally VictoriaMetrics provides the following handlers:
 * `/api/v1/labels/count` - it returns a list of `label: values_count` entries. It can be used for determining labels with the maximum number of values.
 * `/api/v1/status/active_queries` - it returns a list of currently running queries.

+
+### Graphite Metrics API usage
+
+VictoriaMetrics supports the following handlers from [Graphite Metrics API](https://graphite-api.readthedocs.io/en/latest/api.html#the-metrics-api):
+
+* [/metrics/find](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find)
+* [/metrics/expand](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand)
+* [/metrics/index.json](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-index-json)
+
+VictoriaMetrics accepts the following additional query args at `/metrics/find` and `/metrics/expand`:
+  * `label` - for selecting arbitrary label values. By default `label=__name__`, i.e. metric names are selected.
+  * `delimiter` - for using different delimiters in metric name hierachy. For example, `/metrics/find?delimiter=_&query=node_*` would return all the metric name prefixes
+    that start with `node_`. By default `delimiter=.`.
+
+
 ### How to build from sources

 We recommend using either [binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) or
--- a/app/vmselect/graphite/graphite.go
+++ b/app/vmselect/graphite/graphite.go
@ -0,0 +1,383 @@
+package graphite
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/netstorage"
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/searchutils"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
+	"github.com/VictoriaMetrics/metrics"
+)
+
+// MetricsFindHandler implements /metrics/find handler.
+//
+// See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find
+func MetricsFindHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
+	if err := r.ParseForm(); err != nil {
+		return fmt.Errorf("cannot parse form values: %w", err)
+	}
+	format := r.FormValue("format")
+	if format == "" {
+		format = "treejson"
+	}
+	switch format {
+	case "treejson", "completer":
+	default:
+		return fmt.Errorf(`unexpected "format" query arg: %q; expecting "treejson" or "completer"`, format)
+	}
+	query := r.FormValue("query")
+	if len(query) == 0 {
+		return fmt.Errorf("expecting non-empty `query` arg")
+	}
+	delimiter := r.FormValue("delimiter")
+	if delimiter == "" {
+		delimiter = "."
+	}
+	if len(delimiter) > 1 {
+		return fmt.Errorf("`delimiter` query arg must contain only a single char")
+	}
+	if searchutils.GetBool(r, "automatic_variants") {
+		// See https://github.com/graphite-project/graphite-web/blob/bb9feb0e6815faa73f538af6ed35adea0fb273fd/webapp/graphite/metrics/views.py#L152
+		query = addAutomaticVariants(query, delimiter)
+	}
+	if format == "completer" {
+		// See https://github.com/graphite-project/graphite-web/blob/bb9feb0e6815faa73f538af6ed35adea0fb273fd/webapp/graphite/metrics/views.py#L148
+		query = strings.ReplaceAll(query, "..", ".*")
+		if !strings.HasSuffix(query, "*") {
+			query += "*"
+		}
+	}
+	leavesOnly := searchutils.GetBool(r, "leavesOnly")
+	wildcards := searchutils.GetBool(r, "wildcards")
+	label := r.FormValue("label")
+	if label == "__name__" {
+		label = ""
+	}
+	jsonp := r.FormValue("jsonp")
+	from, err := searchutils.GetTime(r, "from", 0)
+	if err != nil {
+		return err
+	}
+	ct := startTime.UnixNano() / 1e6
+	until, err := searchutils.GetTime(r, "until", ct)
+	if err != nil {
+		return err
+	}
+	tr := storage.TimeRange{
+		MinTimestamp: from,
+		MaxTimestamp: until,
+	}
+	paths, err := metricsFind(tr, label, query, delimiter[0], deadline)
+	if err != nil {
+		return err
+	}
+	if leavesOnly {
+		paths = filterLeaves(paths, delimiter)
+	}
+	sortPaths(paths, delimiter)
+	contentType := "application/json"
+	if jsonp != "" {
+		contentType = "text/javascript"
+	}
+	w.Header().Set("Content-Type", contentType)
+	WriteMetricsFindResponse(w, paths, delimiter, format, wildcards, jsonp)
+	metricsFindDuration.UpdateDuration(startTime)
+	return nil
+}
+
+// MetricsExpandHandler implements /metrics/expand handler.
+//
+// See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand
+func MetricsExpandHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
+	if err := r.ParseForm(); err != nil {
+		return fmt.Errorf("cannot parse form values: %w", err)
+	}
+	queries := r.Form["query"]
+	if len(queries) == 0 {
+		return fmt.Errorf("missing `query` arg")
+	}
+	groupByExpr := searchutils.GetBool(r, "groupByExpr")
+	leavesOnly := searchutils.GetBool(r, "leavesOnly")
+	label := r.FormValue("label")
+	if label == "__name__" {
+		label = ""
+	}
+	delimiter := r.FormValue("delimiter")
+	if delimiter == "" {
+		delimiter = "."
+	}
+	if len(delimiter) > 1 {
+		return fmt.Errorf("`delimiter` query arg must contain only a single char")
+	}
+	jsonp := r.FormValue("jsonp")
+	from, err := searchutils.GetTime(r, "from", 0)
+	if err != nil {
+		return err
+	}
+	ct := startTime.UnixNano() / 1e6
+	until, err := searchutils.GetTime(r, "until", ct)
+	if err != nil {
+		return err
+	}
+	tr := storage.TimeRange{
+		MinTimestamp: from,
+		MaxTimestamp: until,
+	}
+	m := make(map[string][]string, len(queries))
+	for _, query := range queries {
+		paths, err := metricsFind(tr, label, query, delimiter[0], deadline)
+		if err != nil {
+			return err
+		}
+		if leavesOnly {
+			paths = filterLeaves(paths, delimiter)
+		}
+		m[query] = paths
+	}
+	contentType := "application/json"
+	if jsonp != "" {
+		contentType = "text/javascript"
+	}
+	w.Header().Set("Content-Type", contentType)
+	if groupByExpr {
+		for _, paths := range m {
+			sortPaths(paths, delimiter)
+		}
+		WriteMetricsExpandResponseByQuery(w, m, jsonp)
+		return nil
+	}
+	paths := m[queries[0]]
+	if len(m) > 1 {
+		pathsSet := make(map[string]struct{})
+		for _, paths := range m {
+			for _, path := range paths {
+				pathsSet[path] = struct{}{}
+			}
+		}
+		paths = make([]string, 0, len(pathsSet))
+		for path := range pathsSet {
+			paths = append(paths, path)
+		}
+	}
+	sortPaths(paths, delimiter)
+	WriteMetricsExpandResponseFlat(w, paths, jsonp)
+	metricsExpandDuration.UpdateDuration(startTime)
+	return nil
+}
+
+// MetricsIndexHandler implements /metrics/index.json handler.
+//
+// See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-index-json
+func MetricsIndexHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
+	if err := r.ParseForm(); err != nil {
+		return fmt.Errorf("cannot parse form values: %w", err)
+	}
+	jsonp := r.FormValue("jsonp")
+	metricNames, err := netstorage.GetLabelValues("__name__", deadline)
+	if err != nil {
+		return fmt.Errorf(`cannot obtain metric names: %w`, err)
+	}
+	contentType := "application/json"
+	if jsonp != "" {
+		contentType = "text/javascript"
+	}
+	w.Header().Set("Content-Type", contentType)
+	WriteMetricsIndexResponse(w, metricNames, jsonp)
+	metricsIndexDuration.UpdateDuration(startTime)
+	return nil
+}
+
+// metricsFind searches for label values that match the given query.
+func metricsFind(tr storage.TimeRange, label, query string, delimiter byte, deadline netstorage.Deadline) ([]string, error) {
+	expandTail := strings.HasSuffix(query, "*")
+	for strings.HasSuffix(query, "*") {
+		query = query[:len(query)-1]
+	}
+	var results []string
+	n := strings.IndexAny(query, "*{[")
+	if n < 0 {
+		suffixes, err := netstorage.GetTagValueSuffixes(tr, label, query, delimiter, deadline)
+		if err != nil {
+			return nil, err
+		}
+		if expandTail {
+			for _, suffix := range suffixes {
+				results = append(results, query+suffix)
+			}
+		} else if isFullMatch(query, suffixes, delimiter) {
+			results = append(results, query)
+		}
+		return results, nil
+	}
+	subquery := query[:n] + "*"
+	paths, err := metricsFind(tr, label, subquery, delimiter, deadline)
+	if err != nil {
+		return nil, err
+	}
+	tail := ""
+	suffix := query[n:]
+	if m := strings.IndexByte(suffix, delimiter); m >= 0 {
+		tail = suffix[m+1:]
+		suffix = suffix[:m+1]
+	}
+	q := query[:n] + suffix
+	re, err := getRegexpForQuery(q, delimiter)
+	if err != nil {
+		return nil, fmt.Errorf("cannot convert query %q to regexp: %w", q, err)
+	}
+	if expandTail {
+		tail += "*"
+	}
+	for _, path := range paths {
+		if !re.MatchString(path) {
+			continue
+		}
+		subquery := path + tail
+		tmp, err := metricsFind(tr, label, subquery, delimiter, deadline)
+		if err != nil {
+			return nil, err
+		}
+		results = append(results, tmp...)
+	}
+	return results, nil
+}
+
+var (
+	metricsFindDuration   = metrics.NewSummary(`vm_request_duration_seconds{path="/metrics/find"}`)
+	metricsExpandDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/metrics/expand"}`)
+	metricsIndexDuration  = metrics.NewSummary(`vm_request_duration_seconds{path="/metrics/expand"}`)
+)
+
+func isFullMatch(tagValuePrefix string, suffixes []string, delimiter byte) bool {
+	if len(suffixes) == 0 {
+		return false
+	}
+	if strings.LastIndexByte(tagValuePrefix, delimiter) == len(tagValuePrefix)-1 {
+		return true
+	}
+	for _, suffix := range suffixes {
+		if suffix == "" {
+			return true
+		}
+	}
+	return false
+}
+
+func addAutomaticVariants(query, delimiter string) string {
+	// See https://github.com/graphite-project/graphite-web/blob/bb9feb0e6815faa73f538af6ed35adea0fb273fd/webapp/graphite/metrics/views.py#L152
+	parts := strings.Split(query, delimiter)
+	for i, part := range parts {
+		if strings.Contains(part, ",") && !strings.Contains(part, "{") {
+			parts[i] = "{" + part + "}"
+		}
+	}
+	return strings.Join(parts, delimiter)
+}
+
+func filterLeaves(paths []string, delimiter string) []string {
+	leaves := paths[:0]
+	for _, path := range paths {
+		if !strings.HasSuffix(path, delimiter) {
+			leaves = append(leaves, path)
+		}
+	}
+	return leaves
+}
+
+func sortPaths(paths []string, delimiter string) {
+	sort.Slice(paths, func(i, j int) bool {
+		a, b := paths[i], paths[j]
+		isNodeA := strings.HasSuffix(a, delimiter)
+		isNodeB := strings.HasSuffix(b, delimiter)
+		if isNodeA == isNodeB {
+			return a < b
+		}
+		return isNodeA
+	})
+}
+
+func getRegexpForQuery(query string, delimiter byte) (*regexp.Regexp, error) {
+	regexpCacheLock.Lock()
+	defer regexpCacheLock.Unlock()
+
+	k := regexpCacheKey{
+		query:     query,
+		delimiter: delimiter,
+	}
+	if re := regexpCache[k]; re != nil {
+		return re.re, re.err
+	}
+	a := make([]string, 0, len(query))
+	tillNextDelimiter := "[^" + regexp.QuoteMeta(string([]byte{delimiter})) + "]*"
+	for i := 0; i < len(query); i++ {
+		switch query[i] {
+		case '*':
+			a = append(a, tillNextDelimiter)
+		case '{':
+			tmp := query[i+1:]
+			if n := strings.IndexByte(tmp, '}'); n < 0 {
+				a = append(a, regexp.QuoteMeta(query[i:]))
+				i = len(query)
+			} else {
+				a = append(a, "(?:")
+				opts := strings.Split(tmp[:n], ",")
+				for j, opt := range opts {
+					opts[j] = regexp.QuoteMeta(opt)
+				}
+				a = append(a, strings.Join(opts, "|"))
+				a = append(a, ")")
+				i += n + 1
+			}
+		case '[':
+			tmp := query[i:]
+			if n := strings.IndexByte(tmp, ']'); n < 0 {
+				a = append(a, regexp.QuoteMeta(query[i:]))
+				i = len(query)
+			} else {
+				a = append(a, tmp[:n+1])
+				i += n
+			}
+		default:
+			a = append(a, regexp.QuoteMeta(query[i:i+1]))
+		}
+	}
+	s := strings.Join(a, "")
+	re, err := regexp.Compile(s)
+	regexpCache[k] = &regexpCacheEntry{
+		re:  re,
+		err: err,
+	}
+	if len(regexpCache) >= maxRegexpCacheSize {
+		for k := range regexpCache {
+			if len(regexpCache) < maxRegexpCacheSize {
+				break
+			}
+			delete(regexpCache, k)
+		}
+	}
+	return re, err
+}
+
+type regexpCacheEntry struct {
+	re  *regexp.Regexp
+	err error
+}
+
+type regexpCacheKey struct {
+	query     string
+	delimiter byte
+}
+
+var regexpCache = make(map[regexpCacheKey]*regexpCacheEntry)
+var regexpCacheLock sync.Mutex
+
+const maxRegexpCacheSize = 10000
--- a/app/vmselect/graphite/graphite_test.go
+++ b/app/vmselect/graphite/graphite_test.go
@ -0,0 +1,71 @@
+package graphite
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestGetRegexpForQuery(t *testing.T) {
+	f := func(query string, delimiter byte, reExpected string) {
+		t.Helper()
+		re, err := getRegexpForQuery(query, delimiter)
+		if err != nil {
+			t.Fatalf("unexpected error in getRegexpForQuery(%q): %s", query, err)
+		}
+		reStr := re.String()
+		if reStr != reExpected {
+			t.Fatalf("unexpected regexp for query=%q, delimiter=%c; got %s; want %s", query, delimiter, reStr, reExpected)
+		}
+	}
+	f("", '.', "")
+	f("foobar", '.', "foobar")
+	f("*", '.', `[^\.]*`)
+	f("*", '_', `[^_]*`)
+	f("foo.*.bar", '.', `foo\.[^\.]*\.bar`)
+	f("fo*b{ar,aaa}[a-z]xx*.d", '.', `fo[^\.]*b(?:ar|aaa)[a-z]xx[^\.]*\.d`)
+	f("fo*b{ar,aaa}[a-z]xx*_d", '_', `fo[^_]*b(?:ar|aaa)[a-z]xx[^_]*_d`)
+}
+
+func TestSortPaths(t *testing.T) {
+	f := func(paths []string, delimiter string, pathsSortedExpected []string) {
+		t.Helper()
+		sortPaths(paths, delimiter)
+		if !reflect.DeepEqual(paths, pathsSortedExpected) {
+			t.Fatalf("unexpected sortPaths result;\ngot\n%q\nwant\n%q", paths, pathsSortedExpected)
+		}
+	}
+	f([]string{"foo", "bar"}, ".", []string{"bar", "foo"})
+	f([]string{"foo.", "bar", "aa", "ab."}, ".", []string{"ab.", "foo.", "aa", "bar"})
+	f([]string{"foo.", "bar", "aa", "ab."}, "_", []string{"aa", "ab.", "bar", "foo."})
+}
+
+func TestFilterLeaves(t *testing.T) {
+	f := func(paths []string, delimiter string, leavesExpected []string) {
+		t.Helper()
+		leaves := filterLeaves(paths, delimiter)
+		if !reflect.DeepEqual(leaves, leavesExpected) {
+			t.Fatalf("unexpected leaves; got\n%q\nwant\n%q", leaves, leavesExpected)
+		}
+	}
+	f([]string{"foo", "bar"}, ".", []string{"foo", "bar"})
+	f([]string{"a.", ".", "bc"}, ".", []string{"bc"})
+	f([]string{"a.", ".", "bc"}, "_", []string{"a.", ".", "bc"})
+	f([]string{"a_", "_", "bc"}, "_", []string{"bc"})
+	f([]string{"foo.", "bar."}, ".", []string{})
+}
+
+func TestAddAutomaticVariants(t *testing.T) {
+	f := func(query, delimiter, resultExpected string) {
+		t.Helper()
+		result := addAutomaticVariants(query, delimiter)
+		if result != resultExpected {
+			t.Fatalf("unexpected result for addAutomaticVariants(%q, delimiter=%q); got %q; want %q", query, delimiter, result, resultExpected)
+		}
+	}
+	f("", ".", "")
+	f("foobar", ".", "foobar")
+	f("foo,bar.baz", ".", "{foo,bar}.baz")
+	f("foo,bar.baz", "_", "{foo,bar.baz}")
+	f("foo,bar_baz*", "_", "{foo,bar}_baz*")
+	f("foo.bar,baz,aa.bb,cc", ".", "foo.{bar,baz,aa}.{bb,cc}")
+}
--- a/app/vmselect/graphite/metrics_expand_response.qtpl
+++ b/app/vmselect/graphite/metrics_expand_response.qtpl
@ -0,0 +1,38 @@
+{% stripspace %}
+
+MetricsExpandResponseByQuery generates response for /metrics/expand?groupByExpr=1 .
+See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand
+{% func MetricsExpandResponseByQuery(m map[string][]string, jsonp string) %}
+	{% if jsonp != "" %}{%s= jsonp %}({% endif %}
+	{
+		"results":{
+			{% code i := 0 %}
+			{% for query, paths := range m %}
+				{%q= query %}:{%= metricPaths(paths) %}
+				{% code i++ %}
+				{% if i < len(m) %},{% endif %}
+			{% endfor %}
+		}
+	}
+	{% if jsonp != "" %}){% endif %}
+{% endfunc %}
+
+
+MetricsExpandResponseFlat generates response for /metrics/expand?groupByExpr=0 .
+See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand
+{% func MetricsExpandResponseFlat(paths []string, jsonp string) %}
+	{% if jsonp != "" %}{%s= jsonp %}({% endif %}
+	{%= metricPaths(paths) %}
+	{% if jsonp != "" %}){% endif %}
+{% endfunc %}
+
+{% func metricPaths(paths []string) %}
+	[
+		{% for i, path := range paths %}
+			{%q= path %}
+			{% if i+1 < len(paths) %},{% endif %}
+		{% endfor %}
+	]
+{% endfunc %}
+
+{% endstripspace %}
--- a/app/vmselect/graphite/metrics_expand_response.qtpl.go
+++ b/app/vmselect/graphite/metrics_expand_response.qtpl.go
@ -0,0 +1,187 @@
+// Code generated by qtc from "metrics_expand_response.qtpl". DO NOT EDIT.
+// See https://github.com/valyala/quicktemplate for details.
+
+// MetricsExpandResponseByQuery generates response for /metrics/expand?groupByExpr=1 .See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:5
+package graphite
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:5
+import (
+	qtio422016 "io"
+
+	qt422016 "github.com/valyala/quicktemplate"
+)
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:5
+var (
+	_ = qtio422016.Copy
+	_ = qt422016.AcquireByteBuffer
+)
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:5
+func StreamMetricsExpandResponseByQuery(qw422016 *qt422016.Writer, m map[string][]string, jsonp string) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:6
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:6
+		qw422016.N().S(jsonp)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:6
+		qw422016.N().S(`(`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:6
+	}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:6
+	qw422016.N().S(`{"results":{`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:9
+	i := 0
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:10
+	for query, paths := range m {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:11
+		qw422016.N().Q(query)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:11
+		qw422016.N().S(`:`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:11
+		streammetricPaths(qw422016, paths)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:12
+		i++
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:13
+		if i < len(m) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:13
+			qw422016.N().S(`,`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:13
+		}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:14
+	}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:14
+	qw422016.N().S(`}}`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:17
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:17
+		qw422016.N().S(`)`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:17
+	}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+func WriteMetricsExpandResponseByQuery(qq422016 qtio422016.Writer, m map[string][]string, jsonp string) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	StreamMetricsExpandResponseByQuery(qw422016, m, jsonp)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+func MetricsExpandResponseByQuery(m map[string][]string, jsonp string) string {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	WriteMetricsExpandResponseByQuery(qb422016, m, jsonp)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+	return qs422016
+//line app/vmselect/graphite/metrics_expand_response.qtpl:18
+}
+
+// MetricsExpandResponseFlat generates response for /metrics/expand?groupByExpr=0 .See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:23
+func StreamMetricsExpandResponseFlat(qw422016 *qt422016.Writer, paths []string, jsonp string) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:24
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:24
+		qw422016.N().S(jsonp)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:24
+		qw422016.N().S(`(`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:24
+	}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:25
+	streammetricPaths(qw422016, paths)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:26
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:26
+		qw422016.N().S(`)`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:26
+	}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+func WriteMetricsExpandResponseFlat(qq422016 qtio422016.Writer, paths []string, jsonp string) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	StreamMetricsExpandResponseFlat(qw422016, paths, jsonp)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+func MetricsExpandResponseFlat(paths []string, jsonp string) string {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	WriteMetricsExpandResponseFlat(qb422016, paths, jsonp)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+	return qs422016
+//line app/vmselect/graphite/metrics_expand_response.qtpl:27
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:29
+func streammetricPaths(qw422016 *qt422016.Writer, paths []string) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:29
+	qw422016.N().S(`[`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:31
+	for i, path := range paths {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:32
+		qw422016.N().Q(path)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:33
+		if i+1 < len(paths) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:33
+			qw422016.N().S(`,`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:33
+		}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:34
+	}
+//line app/vmselect/graphite/metrics_expand_response.qtpl:34
+	qw422016.N().S(`]`)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+func writemetricPaths(qq422016 qtio422016.Writer, paths []string) {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	streammetricPaths(qw422016, paths)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+}
+
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+func metricPaths(paths []string) string {
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	writemetricPaths(qb422016, paths)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+	return qs422016
+//line app/vmselect/graphite/metrics_expand_response.qtpl:36
+}
--- a/app/vmselect/graphite/metrics_find_response.qtpl
+++ b/app/vmselect/graphite/metrics_find_response.qtpl
@ -0,0 +1,110 @@
+{% import (
+	"strings"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+) %}
+
+{% stripspace %}
+
+MetricsFindResponse generates response for /metrics/find .
+See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find
+{% func MetricsFindResponse(paths []string, delimiter, format string, addWildcards bool, jsonp string) %}
+	{% if jsonp != "" %}{%s= jsonp %}({% endif %}
+	{% switch format %}
+	{% case "completer" %}
+		{%= metricsFindResponseCompleter(paths, delimiter, addWildcards) %}
+	{% case "treejson" %}
+		{%= metricsFindResponseTreeJSON(paths, delimiter, addWildcards) %}
+	{% default %}
+		{% code logger.Panicf("BUG: unexpected format=%q", format) %}
+	{% endswitch %}
+	{% if jsonp != "" %}){% endif %}
+{% endfunc %}
+
+{% func metricsFindResponseCompleter(paths []string, delimiter string, addWildcards bool) %}
+{
+	"metrics":[
+		{% for i, path := range paths %}
+		{
+			"path": {%q= path %},
+			"name": {%= metricPathName(path, delimiter) %},
+			"is_leaf": {% if strings.HasSuffix(path, delimiter) %}0{% else %}1{% endif %}
+		}
+		{% if i+1 < len(paths) %},{% endif %}
+		{% endfor %}
+		{% if addWildcards && len(paths) > 1 %}
+		,{
+			"name": "*"
+		}
+		{% endif %}
+	]
+}
+{% endfunc %}
+
+{% func metricsFindResponseTreeJSON(paths []string, delimiter string, addWildcards bool) %}
+[
+	{% for i, path := range paths %}
+	{
+		{% code
+			allowChildren := "0"
+			isLeaf := "1"
+			if strings.HasSuffix(path, delimiter) {
+				allowChildren = "1"
+				isLeaf = "0"
+			}
+		%}
+		"id": {%q= path %},
+		"text": {%= metricPathName(path, delimiter) %},
+		"allowChildren": {%s= allowChildren %},
+		"expandable": {%s= allowChildren %},
+		"leaf": {%s= isLeaf %}
+	}
+	{% if i+1 < len(paths) %},{% endif %}
+	{% endfor %}
+	{% if addWildcards && len(paths) > 1 %}
+	,{
+		{% code
+			path := paths[0]
+			for strings.HasSuffix(path, delimiter) {
+				path = path[:len(path)-1]
+			}
+			id := ""
+			if n := strings.LastIndexByte(path, delimiter[0]); n >= 0 {
+				id = path[:n+1]
+			}
+			id += "*"
+
+			allowChildren := "0"
+			isLeaf := "1"
+			for _, path := range paths {
+				if strings.HasSuffix(path, delimiter) {
+					allowChildren = "1"
+					isLeaf = "0"
+					break
+				}
+			}
+		%}
+		"id": {%q= id %},
+		"text": "*",
+		"allowChildren": {%s= allowChildren %},
+		"expandable": {%s= allowChildren %},
+		"leaf": {%s= isLeaf %}
+	}
+	{% endif %}
+]
+{% endfunc %}
+
+{% func metricPathName(path, delimiter string) %}
+	{% code
+		name := path
+		for strings.HasSuffix(name, delimiter) {
+			name = name[:len(name)-1]
+		}
+		if n := strings.LastIndexByte(name, delimiter[0]); n >= 0 {
+			name = name[n+1:]
+		}
+	%}
+	{%q= name %}
+{% endfunc %}
+
+{% endstripspace %}
--- a/app/vmselect/graphite/metrics_find_response.qtpl.go
+++ b/app/vmselect/graphite/metrics_find_response.qtpl.go
@ -0,0 +1,326 @@
+// Code generated by qtc from "metrics_find_response.qtpl". DO NOT EDIT.
+// See https://github.com/valyala/quicktemplate for details.
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:1
+package graphite
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:1
+import (
+	"strings"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+)
+
+// MetricsFindResponse generates response for /metrics/find .See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:11
+import (
+	qtio422016 "io"
+
+	qt422016 "github.com/valyala/quicktemplate"
+)
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:11
+var (
+	_ = qtio422016.Copy
+	_ = qt422016.AcquireByteBuffer
+)
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:11
+func StreamMetricsFindResponse(qw422016 *qt422016.Writer, paths []string, delimiter, format string, addWildcards bool, jsonp string) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:12
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_find_response.qtpl:12
+		qw422016.N().S(jsonp)
+//line app/vmselect/graphite/metrics_find_response.qtpl:12
+		qw422016.N().S(`(`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:12
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:13
+	switch format {
+//line app/vmselect/graphite/metrics_find_response.qtpl:14
+	case "completer":
+//line app/vmselect/graphite/metrics_find_response.qtpl:15
+		streammetricsFindResponseCompleter(qw422016, paths, delimiter, addWildcards)
+//line app/vmselect/graphite/metrics_find_response.qtpl:16
+	case "treejson":
+//line app/vmselect/graphite/metrics_find_response.qtpl:17
+		streammetricsFindResponseTreeJSON(qw422016, paths, delimiter, addWildcards)
+//line app/vmselect/graphite/metrics_find_response.qtpl:18
+	default:
+//line app/vmselect/graphite/metrics_find_response.qtpl:19
+		logger.Panicf("BUG: unexpected format=%q", format)
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:20
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:21
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_find_response.qtpl:21
+		qw422016.N().S(`)`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:21
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+func WriteMetricsFindResponse(qq422016 qtio422016.Writer, paths []string, delimiter, format string, addWildcards bool, jsonp string) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	StreamMetricsFindResponse(qw422016, paths, delimiter, format, addWildcards, jsonp)
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+func MetricsFindResponse(paths []string, delimiter, format string, addWildcards bool, jsonp string) string {
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	WriteMetricsFindResponse(qb422016, paths, delimiter, format, addWildcards, jsonp)
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+	return qs422016
+//line app/vmselect/graphite/metrics_find_response.qtpl:22
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:24
+func streammetricsFindResponseCompleter(qw422016 *qt422016.Writer, paths []string, delimiter string, addWildcards bool) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:24
+	qw422016.N().S(`{"metrics":[`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:27
+	for i, path := range paths {
+//line app/vmselect/graphite/metrics_find_response.qtpl:27
+		qw422016.N().S(`{"path":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:29
+		qw422016.N().Q(path)
+//line app/vmselect/graphite/metrics_find_response.qtpl:29
+		qw422016.N().S(`,"name":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:30
+		streammetricPathName(qw422016, path, delimiter)
+//line app/vmselect/graphite/metrics_find_response.qtpl:30
+		qw422016.N().S(`,"is_leaf":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:31
+		if strings.HasSuffix(path, delimiter) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:31
+			qw422016.N().S(`0`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:31
+		} else {
+//line app/vmselect/graphite/metrics_find_response.qtpl:31
+			qw422016.N().S(`1`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:31
+		}
+//line app/vmselect/graphite/metrics_find_response.qtpl:31
+		qw422016.N().S(`}`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:33
+		if i+1 < len(paths) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:33
+			qw422016.N().S(`,`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:33
+		}
+//line app/vmselect/graphite/metrics_find_response.qtpl:34
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:35
+	if addWildcards && len(paths) > 1 {
+//line app/vmselect/graphite/metrics_find_response.qtpl:35
+		qw422016.N().S(`,{"name": "*"}`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:39
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:39
+	qw422016.N().S(`]}`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+func writemetricsFindResponseCompleter(qq422016 qtio422016.Writer, paths []string, delimiter string, addWildcards bool) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	streammetricsFindResponseCompleter(qw422016, paths, delimiter, addWildcards)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+func metricsFindResponseCompleter(paths []string, delimiter string, addWildcards bool) string {
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	writemetricsFindResponseCompleter(qb422016, paths, delimiter, addWildcards)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+	return qs422016
+//line app/vmselect/graphite/metrics_find_response.qtpl:42
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:44
+func streammetricsFindResponseTreeJSON(qw422016 *qt422016.Writer, paths []string, delimiter string, addWildcards bool) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:44
+	qw422016.N().S(`[`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:46
+	for i, path := range paths {
+//line app/vmselect/graphite/metrics_find_response.qtpl:46
+		qw422016.N().S(`{`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:49
+		allowChildren := "0"
+		isLeaf := "1"
+		if strings.HasSuffix(path, delimiter) {
+			allowChildren = "1"
+			isLeaf = "0"
+		}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:55
+		qw422016.N().S(`"id":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:56
+		qw422016.N().Q(path)
+//line app/vmselect/graphite/metrics_find_response.qtpl:56
+		qw422016.N().S(`,"text":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:57
+		streammetricPathName(qw422016, path, delimiter)
+//line app/vmselect/graphite/metrics_find_response.qtpl:57
+		qw422016.N().S(`,"allowChildren":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:58
+		qw422016.N().S(allowChildren)
+//line app/vmselect/graphite/metrics_find_response.qtpl:58
+		qw422016.N().S(`,"expandable":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:59
+		qw422016.N().S(allowChildren)
+//line app/vmselect/graphite/metrics_find_response.qtpl:59
+		qw422016.N().S(`,"leaf":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:60
+		qw422016.N().S(isLeaf)
+//line app/vmselect/graphite/metrics_find_response.qtpl:60
+		qw422016.N().S(`}`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:62
+		if i+1 < len(paths) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:62
+			qw422016.N().S(`,`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:62
+		}
+//line app/vmselect/graphite/metrics_find_response.qtpl:63
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:64
+	if addWildcards && len(paths) > 1 {
+//line app/vmselect/graphite/metrics_find_response.qtpl:64
+		qw422016.N().S(`,{`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:67
+		path := paths[0]
+		for strings.HasSuffix(path, delimiter) {
+			path = path[:len(path)-1]
+		}
+		id := ""
+		if n := strings.LastIndexByte(path, delimiter[0]); n >= 0 {
+			id = path[:n+1]
+		}
+		id += "*"
+
+		allowChildren := "0"
+		isLeaf := "1"
+		for _, path := range paths {
+			if strings.HasSuffix(path, delimiter) {
+				allowChildren = "1"
+				isLeaf = "0"
+				break
+			}
+		}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:86
+		qw422016.N().S(`"id":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:87
+		qw422016.N().Q(id)
+//line app/vmselect/graphite/metrics_find_response.qtpl:87
+		qw422016.N().S(`,"text": "*","allowChildren":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:89
+		qw422016.N().S(allowChildren)
+//line app/vmselect/graphite/metrics_find_response.qtpl:89
+		qw422016.N().S(`,"expandable":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:90
+		qw422016.N().S(allowChildren)
+//line app/vmselect/graphite/metrics_find_response.qtpl:90
+		qw422016.N().S(`,"leaf":`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:91
+		qw422016.N().S(isLeaf)
+//line app/vmselect/graphite/metrics_find_response.qtpl:91
+		qw422016.N().S(`}`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:93
+	}
+//line app/vmselect/graphite/metrics_find_response.qtpl:93
+	qw422016.N().S(`]`)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+func writemetricsFindResponseTreeJSON(qq422016 qtio422016.Writer, paths []string, delimiter string, addWildcards bool) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	streammetricsFindResponseTreeJSON(qw422016, paths, delimiter, addWildcards)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+func metricsFindResponseTreeJSON(paths []string, delimiter string, addWildcards bool) string {
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	writemetricsFindResponseTreeJSON(qb422016, paths, delimiter, addWildcards)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+	return qs422016
+//line app/vmselect/graphite/metrics_find_response.qtpl:95
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:97
+func streammetricPathName(qw422016 *qt422016.Writer, path, delimiter string) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:99
+	name := path
+	for strings.HasSuffix(name, delimiter) {
+		name = name[:len(name)-1]
+	}
+	if n := strings.LastIndexByte(name, delimiter[0]); n >= 0 {
+		name = name[n+1:]
+	}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:107
+	qw422016.N().Q(name)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+func writemetricPathName(qq422016 qtio422016.Writer, path, delimiter string) {
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	streammetricPathName(qw422016, path, delimiter)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+}
+
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+func metricPathName(path, delimiter string) string {
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	writemetricPathName(qb422016, path, delimiter)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+	return qs422016
+//line app/vmselect/graphite/metrics_find_response.qtpl:108
+}
--- a/app/vmselect/graphite/metrics_index_response.qtpl
+++ b/app/vmselect/graphite/metrics_index_response.qtpl
@ -0,0 +1,11 @@
+{% stripspace %}
+
+MetricsIndexResponse generates response for /metrics/index.json .
+See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-index-json
+{% func MetricsIndexResponse(metricNames []string, jsonp string) %}
+	{% if jsonp != "" %}{%s= jsonp %}({% endif %}
+	{%= metricPaths(metricNames) %}
+	{% if jsonp != "" %}){% endif %}
+{% endfunc %}
+
+{% endstripspace %}
--- a/app/vmselect/graphite/metrics_index_response.qtpl.go
+++ b/app/vmselect/graphite/metrics_index_response.qtpl.go
@ -0,0 +1,67 @@
+// Code generated by qtc from "metrics_index_response.qtpl". DO NOT EDIT.
+// See https://github.com/valyala/quicktemplate for details.
+
+// MetricsIndexResponse generates response for /metrics/index.json .See https://graphite-api.readthedocs.io/en/latest/api.html#metrics-index-json
+
+//line app/vmselect/graphite/metrics_index_response.qtpl:5
+package graphite
+
+//line app/vmselect/graphite/metrics_index_response.qtpl:5
+import (
+	qtio422016 "io"
+
+	qt422016 "github.com/valyala/quicktemplate"
+)
+
+//line app/vmselect/graphite/metrics_index_response.qtpl:5
+var (
+	_ = qtio422016.Copy
+	_ = qt422016.AcquireByteBuffer
+)
+
+//line app/vmselect/graphite/metrics_index_response.qtpl:5
+func StreamMetricsIndexResponse(qw422016 *qt422016.Writer, metricNames []string, jsonp string) {
+//line app/vmselect/graphite/metrics_index_response.qtpl:6
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_index_response.qtpl:6
+		qw422016.N().S(jsonp)
+//line app/vmselect/graphite/metrics_index_response.qtpl:6
+		qw422016.N().S(`(`)
+//line app/vmselect/graphite/metrics_index_response.qtpl:6
+	}
+//line app/vmselect/graphite/metrics_index_response.qtpl:7
+	streammetricPaths(qw422016, metricNames)
+//line app/vmselect/graphite/metrics_index_response.qtpl:8
+	if jsonp != "" {
+//line app/vmselect/graphite/metrics_index_response.qtpl:8
+		qw422016.N().S(`)`)
+//line app/vmselect/graphite/metrics_index_response.qtpl:8
+	}
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+}
+
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+func WriteMetricsIndexResponse(qq422016 qtio422016.Writer, metricNames []string, jsonp string) {
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	StreamMetricsIndexResponse(qw422016, metricNames, jsonp)
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+}
+
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+func MetricsIndexResponse(metricNames []string, jsonp string) string {
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	WriteMetricsIndexResponse(qb422016, metricNames, jsonp)
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	qs422016 := string(qb422016.B)
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+	return qs422016
+//line app/vmselect/graphite/metrics_index_response.qtpl:9
+}
--- a/app/vmselect/main.go
+++ b/app/vmselect/main.go
@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"

+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/graphite"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/prometheus"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/promql"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmstorage"
@ -203,6 +204,33 @@ func RequestHandler(w http.ResponseWriter, r *http.Request) bool {
 			return true
 		}
 		return true
+	case "/metrics/find", "/metrics/find/":
+		graphiteMetricsFindRequests.Inc()
+		httpserver.EnableCORS(w, r)
+		if err := graphite.MetricsFindHandler(startTime, w, r); err != nil {
+			graphiteMetricsFindErrors.Inc()
+			httpserver.Errorf(w, r, "error in %q: %s", r.URL.Path, err)
+			return true
+		}
+		return true
+	case "/metrics/expand", "/metrics/expand/":
+		graphiteMetricsExpandRequests.Inc()
+		httpserver.EnableCORS(w, r)
+		if err := graphite.MetricsExpandHandler(startTime, w, r); err != nil {
+			graphiteMetricsExpandErrors.Inc()
+			httpserver.Errorf(w, r, "error in %q: %s", r.URL.Path, err)
+			return true
+		}
+		return true
+	case "/metrics/index.json", "/metrics/index.json/":
+		graphiteMetricsIndexRequests.Inc()
+		httpserver.EnableCORS(w, r)
+		if err := graphite.MetricsIndexHandler(startTime, w, r); err != nil {
+			graphiteMetricsIndexErrors.Inc()
+			httpserver.Errorf(w, r, "error in %q: %s", r.URL.Path, err)
+			return true
+		}
+		return true
 	case "/api/v1/rules":
 		// Return dumb placeholder
 		rulesRequests.Inc()
@ -289,6 +317,15 @@ var (
 	federateRequests = metrics.NewCounter(`vm_http_requests_total{path="/federate"}`)
 	federateErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/federate"}`)

+	graphiteMetricsFindRequests = metrics.NewCounter(`vm_http_requests_total{path="/metrics/find"}`)
+	graphiteMetricsFindErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/metrics/find"}`)
+
+	graphiteMetricsExpandRequests = metrics.NewCounter(`vm_http_requests_total{path="/metrics/expand"}`)
+	graphiteMetricsExpandErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/metrics/expand"}`)
+
+	graphiteMetricsIndexRequests = metrics.NewCounter(`vm_http_requests_total{path="/metrics/index.json"}`)
+	graphiteMetricsIndexErrors   = metrics.NewCounter(`vm_http_request_errors_total{path="/metrics/index.json"}`)
+
 	rulesRequests    = metrics.NewCounter(`vm_http_requests_total{path="/api/v1/rules"}`)
 	alertsRequests   = metrics.NewCounter(`vm_http_requests_total{path="/api/v1/alerts"}`)
 	metadataRequests = metrics.NewCounter(`vm_http_requests_total{path="/api/v1/metadata"}`)
--- a/app/vmselect/netstorage/netstorage.go
+++ b/app/vmselect/netstorage/netstorage.go
@ -20,9 +20,10 @@ import (
 )

 var (
-	maxTagKeysPerSearch   = flag.Int("search.maxTagKeys", 100e3, "The maximum number of tag keys returned per search")
-	maxTagValuesPerSearch = flag.Int("search.maxTagValues", 100e3, "The maximum number of tag values returned per search")
-	maxMetricsPerSearch   = flag.Int("search.maxUniqueTimeseries", 300e3, "The maximum number of unique time series each search can scan")
+	maxTagKeysPerSearch          = flag.Int("search.maxTagKeys", 100e3, "The maximum number of tag keys returned from /api/v1/labels")
+	maxTagValuesPerSearch        = flag.Int("search.maxTagValues", 100e3, "The maximum number of tag values returned from /api/v1/label/<label_name>/values")
+	maxTagValueSuffixesPerSearch = flag.Int("search.maxTagValueSuffixesPerSearch", 100e3, "The maximum number of tag value suffixes returned from /metrics/find")
+	maxMetricsPerSearch          = flag.Int("search.maxUniqueTimeseries", 300e3, "The maximum number of unique time series each search can scan")
 )

 // Result is a single timeseries result.
@ -501,6 +502,21 @@ func GetLabelValues(labelName string, deadline Deadline) ([]string, error) {
 	return labelValues, nil
 }

+// GetTagValueSuffixes returns tag value suffixes for the given tagKey and the given tagValuePrefix.
+//
+// It can be used for implementing https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find
+func GetTagValueSuffixes(tr storage.TimeRange, tagKey, tagValuePrefix string, delimiter byte, deadline Deadline) ([]string, error) {
+	if deadline.Exceeded() {
+		return nil, fmt.Errorf("timeout exceeded before starting the query processing: %s", deadline.String())
+	}
+	suffixes, err := vmstorage.SearchTagValueSuffixes(tr, []byte(tagKey), []byte(tagValuePrefix), delimiter, *maxTagValueSuffixesPerSearch, deadline.deadline)
+	if err != nil {
+		return nil, fmt.Errorf("error during search for suffixes for tagKey=%q, tagValuePrefix=%q, delimiter=%c on time range %s: %w",
+			tagKey, tagValuePrefix, delimiter, tr.String(), err)
+	}
+	return suffixes, nil
+}
+
 // GetLabelEntries returns all the label entries until the given deadline.
 func GetLabelEntries(deadline Deadline) ([]storage.TagEntry, error) {
 	if deadline.Exceeded() {
--- a/app/vmselect/prometheus/prometheus.go
+++ b/app/vmselect/prometheus/prometheus.go
@ -8,12 +8,12 @@ import (
 	"runtime"
 	"sort"
 	"strconv"
-	"strings"
 	"sync"
 	"time"

 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/netstorage"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/promql"
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/searchutils"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/httpserver"
@ -28,10 +28,8 @@ import (
 var (
 	latencyOffset = flag.Duration("search.latencyOffset", time.Second*30, "The time when data points become visible in query results after the colection. "+
 		"Too small value can result in incomplete last points for query results")
-	maxExportDuration = flag.Duration("search.maxExportDuration", time.Hour*24*30, "The maximum duration for /api/v1/export call")
-	maxQueryDuration  = flag.Duration("search.maxQueryDuration", time.Second*30, "The maximum duration for search query execution")
-	maxQueryLen       = flagutil.NewBytes("search.maxQueryLen", 16*1024, "The maximum search query length in bytes")
-	maxLookback       = flag.Duration("search.maxLookback", 0, "Synonim to -search.lookback-delta from Prometheus. "+
+	maxQueryLen = flagutil.NewBytes("search.maxQueryLen", 16*1024, "The maximum search query length in bytes")
+	maxLookback = flag.Duration("search.maxLookback", 0, "Synonim to -search.lookback-delta from Prometheus. "+
 		"The value is dynamically detected from interval between time series datapoints if not set. It can be overridden on per-query basis via max_lookback arg. "+
 		"See also '-search.maxStalenessInterval' flag, which has the same meaining due to historical reasons")
 	maxStalenessInterval = flag.Duration("search.maxStalenessInterval", 0, "The maximum interval for staleness calculations. "+
@ -60,15 +58,15 @@ func FederateHandler(startTime time.Time, w http.ResponseWriter, r *http.Request
 	if lookbackDelta <= 0 {
 		lookbackDelta = defaultStep
 	}
-	start, err := getTime(r, "start", ct-lookbackDelta)
+	start, err := searchutils.GetTime(r, "start", ct-lookbackDelta)
 	if err != nil {
 		return err
 	}
-	end, err := getTime(r, "end", ct)
+	end, err := searchutils.GetTime(r, "end", ct)
 	if err != nil {
 		return err
 	}
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
 	if start >= end {
 		start = end - defaultStep
 	}
@ -129,17 +127,17 @@ func ExportHandler(startTime time.Time, w http.ResponseWriter, r *http.Request)
 		}
 		matches = []string{match}
 	}
-	start, err := getTime(r, "start", 0)
+	start, err := searchutils.GetTime(r, "start", 0)
 	if err != nil {
 		return err
 	}
-	end, err := getTime(r, "end", ct)
+	end, err := searchutils.GetTime(r, "end", ct)
 	if err != nil {
 		return err
 	}
 	format := r.FormValue("format")
 	maxRowsPerLine := int(fastfloat.ParseInt64BestEffort(r.FormValue("max_rows_per_line")))
-	deadline := getDeadlineForExport(r, startTime)
+	deadline := searchutils.GetDeadlineForExport(r, startTime)
 	if start >= end {
 		end = start + defaultStep
 	}
@ -283,7 +281,7 @@ var deleteDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#querying-label-values
 func LabelValuesHandler(startTime time.Time, labelName string, w http.ResponseWriter, r *http.Request) error {
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("cannot parse form values: %w", err)
 	}
@ -304,11 +302,11 @@ func LabelValuesHandler(startTime time.Time, labelName string, w http.ResponseWr
 			matches = []string{fmt.Sprintf("{%s!=''}", labelName)}
 		}
 		ct := startTime.UnixNano() / 1e6
-		end, err := getTime(r, "end", ct)
+		end, err := searchutils.GetTime(r, "end", ct)
 		if err != nil {
 			return err
 		}
-		start, err := getTime(r, "start", end-defaultStep)
+		start, err := searchutils.GetTime(r, "start", end-defaultStep)
 		if err != nil {
 			return err
 		}
@ -385,7 +383,7 @@ var labelValuesDuration = metrics.NewSummary(`vm_request_duration_seconds{path="

 // LabelsCountHandler processes /api/v1/labels/count request.
 func LabelsCountHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
 	labelEntries, err := netstorage.GetLabelEntries(deadline)
 	if err != nil {
 		return fmt.Errorf(`cannot obtain label entries: %w`, err)
@ -404,7 +402,7 @@ const secsPerDay = 3600 * 24
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#tsdb-stats
 func TSDBStatusHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("cannot parse form values: %w", err)
 	}
@ -448,7 +446,7 @@ var tsdbStatusDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#getting-label-names
 func LabelsHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("cannot parse form values: %w", err)
 	}
@ -467,11 +465,11 @@ func LabelsHandler(startTime time.Time, w http.ResponseWriter, r *http.Request)
 			matches = []string{"{__name__!=''}"}
 		}
 		ct := startTime.UnixNano() / 1e6
-		end, err := getTime(r, "end", ct)
+		end, err := searchutils.GetTime(r, "end", ct)
 		if err != nil {
 			return err
 		}
-		start, err := getTime(r, "start", end-defaultStep)
+		start, err := searchutils.GetTime(r, "start", end-defaultStep)
 		if err != nil {
 			return err
 		}
@ -536,7 +534,7 @@ var labelsDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/

 // SeriesCountHandler processes /api/v1/series/count request.
 func SeriesCountHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) error {
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
 	n, err := netstorage.GetSeriesCount(deadline)
 	if err != nil {
 		return fmt.Errorf("cannot obtain series count: %w", err)
@ -561,20 +559,20 @@ func SeriesHandler(startTime time.Time, w http.ResponseWriter, r *http.Request)
 	if len(matches) == 0 {
 		return fmt.Errorf("missing `match[]` arg")
 	}
-	end, err := getTime(r, "end", ct)
+	end, err := searchutils.GetTime(r, "end", ct)
 	if err != nil {
 		return err
 	}
-	// Do not set start to minTimeMsecs by default as Prometheus does,
+	// Do not set start to searchutils.minTimeMsecs by default as Prometheus does,
 	// since this leads to fetching and scanning all the data from the storage,
 	// which can take a lot of time for big storages.
 	// It is better setting start as end-defaultStep by default.
 	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/91
-	start, err := getTime(r, "start", end-defaultStep)
+	start, err := searchutils.GetTime(r, "start", end-defaultStep)
 	if err != nil {
 		return err
 	}
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)

 	tagFilterss, err := getTagFilterssFromMatches(matches)
 	if err != nil {
@ -632,7 +630,7 @@ func QueryHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) e
 	if len(query) == 0 {
 		return fmt.Errorf("missing `query` arg")
 	}
-	start, err := getTime(r, "time", ct)
+	start, err := searchutils.GetTime(r, "time", ct)
 	if err != nil {
 		return err
 	}
@ -640,20 +638,20 @@ func QueryHandler(startTime time.Time, w http.ResponseWriter, r *http.Request) e
 	if err != nil {
 		return err
 	}
-	step, err := getDuration(r, "step", lookbackDelta)
+	step, err := searchutils.GetDuration(r, "step", lookbackDelta)
 	if err != nil {
 		return err
 	}
 	if step <= 0 {
 		step = defaultStep
 	}
-	deadline := getDeadlineForQuery(r, startTime)
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)

 	if len(query) > maxQueryLen.N {
 		return fmt.Errorf("too long query; got %d bytes; mustn't exceed `-search.maxQueryLen=%d` bytes", len(query), maxQueryLen.N)
 	}
 	queryOffset := getLatencyOffsetMilliseconds()
-	if !getBool(r, "nocache") && ct-start < queryOffset {
+	if !searchutils.GetBool(r, "nocache") && ct-start < queryOffset {
 		// Adjust start time only if `nocache` arg isn't set.
 		// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/241
 		start = ct - queryOffset
@ -746,15 +744,15 @@ func QueryRangeHandler(startTime time.Time, w http.ResponseWriter, r *http.Reque
 	if len(query) == 0 {
 		return fmt.Errorf("missing `query` arg")
 	}
-	start, err := getTime(r, "start", ct-defaultStep)
+	start, err := searchutils.GetTime(r, "start", ct-defaultStep)
 	if err != nil {
 		return err
 	}
-	end, err := getTime(r, "end", ct)
+	end, err := searchutils.GetTime(r, "end", ct)
 	if err != nil {
 		return err
 	}
-	step, err := getDuration(r, "step", defaultStep)
+	step, err := searchutils.GetDuration(r, "step", defaultStep)
 	if err != nil {
 		return err
 	}
@ -766,8 +764,8 @@ func QueryRangeHandler(startTime time.Time, w http.ResponseWriter, r *http.Reque
 }

 func queryRangeHandler(startTime time.Time, w http.ResponseWriter, query string, start, end, step int64, r *http.Request, ct int64) error {
-	deadline := getDeadlineForQuery(r, startTime)
-	mayCache := !getBool(r, "nocache")
+	deadline := searchutils.GetDeadlineForQuery(r, startTime)
+	mayCache := !searchutils.GetBool(r, "nocache")
 	lookbackDelta, err := getMaxLookback(r)
 	if err != nil {
 		return err
@ -887,120 +885,12 @@ func adjustLastPoints(tss []netstorage.Result, start, end int64) []netstorage.Re
 	return tss
 }

-func getTime(r *http.Request, argKey string, defaultValue int64) (int64, error) {
-	argValue := r.FormValue(argKey)
-	if len(argValue) == 0 {
-		return defaultValue, nil
-	}
-	secs, err := strconv.ParseFloat(argValue, 64)
-	if err != nil {
-		// Try parsing string format
-		t, err := time.Parse(time.RFC3339, argValue)
-		if err != nil {
-			// Handle Prometheus'-provided minTime and maxTime.
-			// See https://github.com/prometheus/client_golang/issues/614
-			switch argValue {
-			case prometheusMinTimeFormatted:
-				return minTimeMsecs, nil
-			case prometheusMaxTimeFormatted:
-				return maxTimeMsecs, nil
-			}
-			// Try parsing duration relative to the current time
-			d, err1 := metricsql.DurationValue(argValue, 0)
-			if err1 != nil {
-				return 0, fmt.Errorf("cannot parse %q=%q: %w", argKey, argValue, err)
-			}
-			if d > 0 {
-				d = -d
-			}
-			t = time.Now().Add(time.Duration(d) * time.Millisecond)
-		}
-		secs = float64(t.UnixNano()) / 1e9
-	}
-	msecs := int64(secs * 1e3)
-	if msecs < minTimeMsecs {
-		msecs = 0
-	}
-	if msecs > maxTimeMsecs {
-		msecs = maxTimeMsecs
-	}
-	return msecs, nil
-}
-
-var (
-	// These constants were obtained from https://github.com/prometheus/prometheus/blob/91d7175eaac18b00e370965f3a8186cc40bf9f55/web/api/v1/api.go#L442
-	// See https://github.com/prometheus/client_golang/issues/614 for details.
-	prometheusMinTimeFormatted = time.Unix(math.MinInt64/1000+62135596801, 0).UTC().Format(time.RFC3339Nano)
-	prometheusMaxTimeFormatted = time.Unix(math.MaxInt64/1000-62135596801, 999999999).UTC().Format(time.RFC3339Nano)
-)
-
-const (
-	// These values prevent from overflow when storing msec-precision time in int64.
-	minTimeMsecs = 0 // use 0 instead of `int64(-1<<63) / 1e6` because the storage engine doesn't actually support negative time
-	maxTimeMsecs = int64(1<<63-1) / 1e6
-)
-
-func getDuration(r *http.Request, argKey string, defaultValue int64) (int64, error) {
-	argValue := r.FormValue(argKey)
-	if len(argValue) == 0 {
-		return defaultValue, nil
-	}
-	secs, err := strconv.ParseFloat(argValue, 64)
-	if err != nil {
-		// Try parsing string format
-		d, err := metricsql.DurationValue(argValue, 0)
-		if err != nil {
-			return 0, fmt.Errorf("cannot parse %q=%q: %w", argKey, argValue, err)
-		}
-		secs = float64(d) / 1000
-	}
-	msecs := int64(secs * 1e3)
-	if msecs <= 0 || msecs > maxDurationMsecs {
-		return 0, fmt.Errorf("%q=%dms is out of allowed range [%d ... %d]", argKey, msecs, 0, int64(maxDurationMsecs))
-	}
-	return msecs, nil
-}
-
-const maxDurationMsecs = 100 * 365 * 24 * 3600 * 1000
-
 func getMaxLookback(r *http.Request) (int64, error) {
 	d := maxLookback.Milliseconds()
 	if d == 0 {
 		d = maxStalenessInterval.Milliseconds()
 	}
-	return getDuration(r, "max_lookback", d)
-}
-
-func getDeadlineForQuery(r *http.Request, startTime time.Time) netstorage.Deadline {
-	dMax := maxQueryDuration.Milliseconds()
-	return getDeadlineWithMaxDuration(r, startTime, dMax, "-search.maxQueryDuration")
-}
-
-func getDeadlineForExport(r *http.Request, startTime time.Time) netstorage.Deadline {
-	dMax := maxExportDuration.Milliseconds()
-	return getDeadlineWithMaxDuration(r, startTime, dMax, "-search.maxExportDuration")
-}
-
-func getDeadlineWithMaxDuration(r *http.Request, startTime time.Time, dMax int64, flagHint string) netstorage.Deadline {
-	d, err := getDuration(r, "timeout", 0)
-	if err != nil {
-		d = 0
-	}
-	if d <= 0 || d > dMax {
-		d = dMax
-	}
-	timeout := time.Duration(d) * time.Millisecond
-	return netstorage.NewDeadline(startTime, timeout, flagHint)
-}
-
-func getBool(r *http.Request, argKey string) bool {
-	argValue := r.FormValue(argKey)
-	switch strings.ToLower(argValue) {
-	case "", "0", "f", "false", "no":
-		return false
-	default:
-		return true
-	}
+	return searchutils.GetDuration(r, "max_lookback", d)
 }

 func getTagFilterssFromMatches(matches []string) ([][]storage.TagFilter, error) {
--- a/app/vmselect/prometheus/prometheus_test.go
+++ b/app/vmselect/prometheus/prometheus_test.go
@ -1,10 +1,7 @@
 package prometheus

 import (
-	"fmt"
 	"math"
-	"net/http"
-	"net/url"
 	"reflect"
 	"testing"

@ -50,76 +47,6 @@ func TestRemoveEmptyValuesAndTimeseries(t *testing.T) {
 	})
 }

-func TestGetTimeSuccess(t *testing.T) {
-	f := func(s string, timestampExpected int64) {
-		t.Helper()
-		urlStr := fmt.Sprintf("http://foo.bar/baz?s=%s", url.QueryEscape(s))
-		r, err := http.NewRequest("GET", urlStr, nil)
-		if err != nil {
-			t.Fatalf("unexpected error in NewRequest: %s", err)
-		}
-
-		// Verify defaultValue
-		ts, err := getTime(r, "foo", 123)
-		if err != nil {
-			t.Fatalf("unexpected error when obtaining default time from getTime(%q): %s", s, err)
-		}
-		if ts != 123 {
-			t.Fatalf("unexpected default value for getTime(%q); got %d; want %d", s, ts, 123)
-		}
-
-		// Verify timestampExpected
-		ts, err = getTime(r, "s", 123)
-		if err != nil {
-			t.Fatalf("unexpected error in getTime(%q): %s", s, err)
-		}
-		if ts != timestampExpected {
-			t.Fatalf("unexpected timestamp for getTime(%q); got %d; want %d", s, ts, timestampExpected)
-		}
-	}
-
-	f("2019-07-07T20:01:02Z", 1562529662000)
-	f("2019-07-07T20:47:40+03:00", 1562521660000)
-	f("-292273086-05-16T16:47:06Z", minTimeMsecs)
-	f("292277025-08-18T07:12:54.999999999Z", maxTimeMsecs)
-	f("1562529662.324", 1562529662324)
-	f("-9223372036.854", minTimeMsecs)
-	f("-9223372036.855", minTimeMsecs)
-	f("9223372036.855", maxTimeMsecs)
-}
-
-func TestGetTimeError(t *testing.T) {
-	f := func(s string) {
-		t.Helper()
-		urlStr := fmt.Sprintf("http://foo.bar/baz?s=%s", url.QueryEscape(s))
-		r, err := http.NewRequest("GET", urlStr, nil)
-		if err != nil {
-			t.Fatalf("unexpected error in NewRequest: %s", err)
-		}
-
-		// Verify defaultValue
-		ts, err := getTime(r, "foo", 123)
-		if err != nil {
-			t.Fatalf("unexpected error when obtaining default time from getTime(%q): %s", s, err)
-		}
-		if ts != 123 {
-			t.Fatalf("unexpected default value for getTime(%q); got %d; want %d", s, ts, 123)
-		}
-
-		// Verify timestampExpected
-		_, err = getTime(r, "s", 123)
-		if err == nil {
-			t.Fatalf("expecting non-nil error in getTime(%q)", s)
-		}
-	}
-
-	f("foo")
-	f("2019-07-07T20:01:02Zisdf")
-	f("2019-07-07T20:47:40+03:00123")
-	f("-292273086-05-16T16:47:07Z")
-	f("292277025-08-18T07:12:54.999999998Z")
-}
-
 func TestAdjustLastPoints(t *testing.T) {
 	f := func(tss []netstorage.Result, start, end int64, tssExpected []netstorage.Result) {
 		t.Helper()
--- a/app/vmselect/searchutils/searchutils.go
+++ b/app/vmselect/searchutils/searchutils.go
@ -0,0 +1,132 @@
+package searchutils
+
+import (
+	"flag"
+	"fmt"
+	"math"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/netstorage"
+	"github.com/VictoriaMetrics/metricsql"
+)
+
+var (
+	maxExportDuration = flag.Duration("search.maxExportDuration", time.Hour*24*30, "The maximum duration for /api/v1/export call")
+	maxQueryDuration  = flag.Duration("search.maxQueryDuration", time.Second*30, "The maximum duration for search query execution")
+)
+
+// GetTime returns time from the given argKey query arg.
+func GetTime(r *http.Request, argKey string, defaultValue int64) (int64, error) {
+	argValue := r.FormValue(argKey)
+	if len(argValue) == 0 {
+		return defaultValue, nil
+	}
+	secs, err := strconv.ParseFloat(argValue, 64)
+	if err != nil {
+		// Try parsing string format
+		t, err := time.Parse(time.RFC3339, argValue)
+		if err != nil {
+			// Handle Prometheus'-provided minTime and maxTime.
+			// See https://github.com/prometheus/client_golang/issues/614
+			switch argValue {
+			case prometheusMinTimeFormatted:
+				return minTimeMsecs, nil
+			case prometheusMaxTimeFormatted:
+				return maxTimeMsecs, nil
+			}
+			// Try parsing duration relative to the current time
+			d, err1 := metricsql.DurationValue(argValue, 0)
+			if err1 != nil {
+				return 0, fmt.Errorf("cannot parse %q=%q: %w", argKey, argValue, err)
+			}
+			if d > 0 {
+				d = -d
+			}
+			t = time.Now().Add(time.Duration(d) * time.Millisecond)
+		}
+		secs = float64(t.UnixNano()) / 1e9
+	}
+	msecs := int64(secs * 1e3)
+	if msecs < minTimeMsecs {
+		msecs = 0
+	}
+	if msecs > maxTimeMsecs {
+		msecs = maxTimeMsecs
+	}
+	return msecs, nil
+}
+
+var (
+	// These constants were obtained from https://github.com/prometheus/prometheus/blob/91d7175eaac18b00e370965f3a8186cc40bf9f55/web/api/v1/api.go#L442
+	// See https://github.com/prometheus/client_golang/issues/614 for details.
+	prometheusMinTimeFormatted = time.Unix(math.MinInt64/1000+62135596801, 0).UTC().Format(time.RFC3339Nano)
+	prometheusMaxTimeFormatted = time.Unix(math.MaxInt64/1000-62135596801, 999999999).UTC().Format(time.RFC3339Nano)
+)
+
+const (
+	// These values prevent from overflow when storing msec-precision time in int64.
+	minTimeMsecs = 0 // use 0 instead of `int64(-1<<63) / 1e6` because the storage engine doesn't actually support negative time
+	maxTimeMsecs = int64(1<<63-1) / 1e6
+)
+
+// GetDuration returns duration from the given argKey query arg.
+func GetDuration(r *http.Request, argKey string, defaultValue int64) (int64, error) {
+	argValue := r.FormValue(argKey)
+	if len(argValue) == 0 {
+		return defaultValue, nil
+	}
+	secs, err := strconv.ParseFloat(argValue, 64)
+	if err != nil {
+		// Try parsing string format
+		d, err := metricsql.DurationValue(argValue, 0)
+		if err != nil {
+			return 0, fmt.Errorf("cannot parse %q=%q: %w", argKey, argValue, err)
+		}
+		secs = float64(d) / 1000
+	}
+	msecs := int64(secs * 1e3)
+	if msecs <= 0 || msecs > maxDurationMsecs {
+		return 0, fmt.Errorf("%q=%dms is out of allowed range [%d ... %d]", argKey, msecs, 0, int64(maxDurationMsecs))
+	}
+	return msecs, nil
+}
+
+const maxDurationMsecs = 100 * 365 * 24 * 3600 * 1000
+
+// GetDeadlineForQuery returns deadline for the given query r.
+func GetDeadlineForQuery(r *http.Request, startTime time.Time) netstorage.Deadline {
+	dMax := maxQueryDuration.Milliseconds()
+	return getDeadlineWithMaxDuration(r, startTime, dMax, "-search.maxQueryDuration")
+}
+
+// GetDeadlineForExport returns deadline for the given request to /api/v1/export.
+func GetDeadlineForExport(r *http.Request, startTime time.Time) netstorage.Deadline {
+	dMax := maxExportDuration.Milliseconds()
+	return getDeadlineWithMaxDuration(r, startTime, dMax, "-search.maxExportDuration")
+}
+
+func getDeadlineWithMaxDuration(r *http.Request, startTime time.Time, dMax int64, flagHint string) netstorage.Deadline {
+	d, err := GetDuration(r, "timeout", 0)
+	if err != nil {
+		d = 0
+	}
+	if d <= 0 || d > dMax {
+		d = dMax
+	}
+	timeout := time.Duration(d) * time.Millisecond
+	return netstorage.NewDeadline(startTime, timeout, flagHint)
+}
+
+// GetBool returns boolean value from the given argKey query arg.
+func GetBool(r *http.Request, argKey string) bool {
+	argValue := r.FormValue(argKey)
+	switch strings.ToLower(argValue) {
+	case "", "0", "f", "false", "no":
+		return false
+	default:
+		return true
+	}
+}
--- a/app/vmselect/searchutils/searchutils_test.go
+++ b/app/vmselect/searchutils/searchutils_test.go
@ -0,0 +1,78 @@
+package searchutils
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"testing"
+)
+
+func TestGetTimeSuccess(t *testing.T) {
+	f := func(s string, timestampExpected int64) {
+		t.Helper()
+		urlStr := fmt.Sprintf("http://foo.bar/baz?s=%s", url.QueryEscape(s))
+		r, err := http.NewRequest("GET", urlStr, nil)
+		if err != nil {
+			t.Fatalf("unexpected error in NewRequest: %s", err)
+		}
+
+		// Verify defaultValue
+		ts, err := GetTime(r, "foo", 123)
+		if err != nil {
+			t.Fatalf("unexpected error when obtaining default time from GetTime(%q): %s", s, err)
+		}
+		if ts != 123 {
+			t.Fatalf("unexpected default value for GetTime(%q); got %d; want %d", s, ts, 123)
+		}
+
+		// Verify timestampExpected
+		ts, err = GetTime(r, "s", 123)
+		if err != nil {
+			t.Fatalf("unexpected error in GetTime(%q): %s", s, err)
+		}
+		if ts != timestampExpected {
+			t.Fatalf("unexpected timestamp for GetTime(%q); got %d; want %d", s, ts, timestampExpected)
+		}
+	}
+
+	f("2019-07-07T20:01:02Z", 1562529662000)
+	f("2019-07-07T20:47:40+03:00", 1562521660000)
+	f("-292273086-05-16T16:47:06Z", minTimeMsecs)
+	f("292277025-08-18T07:12:54.999999999Z", maxTimeMsecs)
+	f("1562529662.324", 1562529662324)
+	f("-9223372036.854", minTimeMsecs)
+	f("-9223372036.855", minTimeMsecs)
+	f("9223372036.855", maxTimeMsecs)
+}
+
+func TestGetTimeError(t *testing.T) {
+	f := func(s string) {
+		t.Helper()
+		urlStr := fmt.Sprintf("http://foo.bar/baz?s=%s", url.QueryEscape(s))
+		r, err := http.NewRequest("GET", urlStr, nil)
+		if err != nil {
+			t.Fatalf("unexpected error in NewRequest: %s", err)
+		}
+
+		// Verify defaultValue
+		ts, err := GetTime(r, "foo", 123)
+		if err != nil {
+			t.Fatalf("unexpected error when obtaining default time from GetTime(%q): %s", s, err)
+		}
+		if ts != 123 {
+			t.Fatalf("unexpected default value for GetTime(%q); got %d; want %d", s, ts, 123)
+		}
+
+		// Verify timestampExpected
+		_, err = GetTime(r, "s", 123)
+		if err == nil {
+			t.Fatalf("expecting non-nil error in GetTime(%q)", s)
+		}
+	}
+
+	f("foo")
+	f("2019-07-07T20:01:02Zisdf")
+	f("2019-07-07T20:47:40+03:00123")
+	f("-292273086-05-16T16:47:07Z")
+	f("292277025-08-18T07:12:54.999999998Z")
+}
--- a/app/vmstorage/main.go
+++ b/app/vmstorage/main.go
@ -132,6 +132,16 @@ func SearchTagValues(tagKey []byte, maxTagValues int, deadline uint64) ([]string
 	return values, err
 }

+// SearchTagValueSuffixes returns all the tag value suffixes for the given tagKey and tagValuePrefix on the given tr.
+//
+// This allows implementing https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find or similar APIs.
+func SearchTagValueSuffixes(tr storage.TimeRange, tagKey, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int, deadline uint64) ([]string, error) {
+	WG.Add(1)
+	suffixes, err := Storage.SearchTagValueSuffixes(tr, tagKey, tagValuePrefix, delimiter, maxTagValueSuffixes, deadline)
+	WG.Done()
+	return suffixes, err
+}
+
 // SearchTagEntries searches for tag entries.
 func SearchTagEntries(maxTagKeys, maxTagValues int, deadline uint64) ([]storage.TagEntry, error) {
 	WG.Add(1)
--- a/docs/Cluster-VictoriaMetrics.md
+++ b/docs/Cluster-VictoriaMetrics.md
@ -180,7 +180,7 @@ or [an alternative dashboard for VictoriaMetrics cluster](https://grafana.com/gr
     - `prometheus/api/v1/import/csv` - for importing arbitrary CSV data. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-import-csv-data) for details.
     - `prometheus/api/v1/import/prometheus` - for importing data in Prometheus exposition format. See [these docs](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-import-data-in-prometheus-exposition-format) for details.

-* URLs for querying: `http://<vmselect>:8481/select/<accountID>/prometheus/<suffix>`, where:
+* URLs for [Prmetheus querying API](https://prometheus.io/docs/prometheus/latest/querying/api/): `http://<vmselect>:8481/select/<accountID>/prometheus/<suffix>`, where:
  - `<accountID>` is an arbitrary number identifying data namespace for the query (aka tenant)
  - `<suffix>` may have the following values:
    - `api/v1/query` - performs [PromQL instant query](https://prometheus.io/docs/prometheus/latest/querying/api/#instant-queries).
@ -194,6 +194,13 @@ or [an alternative dashboard for VictoriaMetrics cluster](https://grafana.com/gr
    - `api/v1/status/active_queries` - for currently executed active queries. Note that every `vmselect` maintains an independent list of active queries,
      which is returned in the response.

+* URLs for [Graphite Metrics API](https://graphite-api.readthedocs.io/en/latest/api.html#the-metrics-api): `http://<vmselect>:8481/select/<accountID>/graphite/<suffix>`, where:
+    - `<accountID>` is an arbitrary number identifying data namespace for query (aka tenant)
+    - `<suffix>` may have the following values:
+      - `metrics/find` - searches Graphite metrics. See [these docs](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find).
+      - `metrics/expand` - expands Graphite metrics. See [these docs](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand).
+      - `metrics/index.json` - returns all the metric names. See [these docs](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-index-json).
+
 * URL for time series deletion: `http://<vmselect>:8481/delete/<accountID>/prometheus/api/v1/admin/tsdb/delete_series?match[]=<timeseries_selector_for_delete>`.
  Note that the `delete_series` handler should be used only in exceptional cases such as deletion of accidentally ingested incorrect time series. It shouldn't
  be used on a regular basis, since it carries non-zero overhead.
--- a/docs/Single-server-VictoriaMetrics.md
+++ b/docs/Single-server-VictoriaMetrics.md
@ -103,6 +103,8 @@ See [features available for enterprise customers](https://github.com/VictoriaMet
 * [How to import data in Prometheus exposition format](#how-to-import-data-in-prometheus-exposition-format)
 * [How to import CSV data](#how-to-import-csv-data)
 * [Prometheus querying API usage](#prometheus-querying-api-usage)
+  * [Prometheus querying API enhancements](#prometheus-querying-api-enhancements)
+* [Graphite Metrics API usage](#graphite-metrics-api-usage)
 * [How to build from sources](#how-to-build-from-sources)
  * [Development build](#development-build)
  * [Production build](#production-build)
@ -392,9 +394,11 @@ The `/api/v1/export` endpoint should return the following response:

 ### Querying Graphite data

-Data sent to VictoriaMetrics via `Graphite plaintext protocol` may be read either via
-[Prometheus querying API](#prometheus-querying-api-usage)
-or via [go-graphite/carbonapi](https://github.com/go-graphite/carbonapi/blob/master/cmd/carbonapi/carbonapi.example.prometheus.yaml).
+Data sent to VictoriaMetrics via `Graphite plaintext protocol` may be read via the following APIs:
+
+* [Prometheus querying API](#prometheus-querying-api-usage)
+* Metric names can be explored via [Graphite metrics API](#graphite-metrics-api-usage)
+* [go-graphite/carbonapi](https://github.com/go-graphite/carbonapi/blob/master/cmd/carbonapi/carbonapi.example.prometheus.yaml)

 ### How to send data from OpenTSDB-compatible agents

@ -585,6 +589,21 @@ Additionally VictoriaMetrics provides the following handlers:
 * `/api/v1/labels/count` - it returns a list of `label: values_count` entries. It can be used for determining labels with the maximum number of values.
 * `/api/v1/status/active_queries` - it returns a list of currently running queries.

+
+### Graphite Metrics API usage
+
+VictoriaMetrics supports the following handlers from [Graphite Metrics API](https://graphite-api.readthedocs.io/en/latest/api.html#the-metrics-api):
+
+* [/metrics/find](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find)
+* [/metrics/expand](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-expand)
+* [/metrics/index.json](https://graphite-api.readthedocs.io/en/latest/api.html#metrics-index-json)
+
+VictoriaMetrics accepts the following additional query args at `/metrics/find` and `/metrics/expand`:
+  * `label` - for selecting arbitrary label values. By default `label=__name__`, i.e. metric names are selected.
+  * `delimiter` - for using different delimiters in metric name hierachy. For example, `/metrics/find?delimiter=_&query=node_*` would return all the metric name prefixes
+    that start with `node_`. By default `delimiter=.`.
+
+
 ### How to build from sources

 We recommend using either [binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) or
--- a/lib/storage/index_db.go
+++ b/lib/storage/index_db.go
@ -901,6 +901,152 @@ func (is *indexSearch) searchTagValues(tvs map[string]struct{}, tagKey []byte, m
 	return nil
 }

+// SearchTagValueSuffixes returns all the tag value suffixes for the given tagKey and tagValuePrefix on the given tr.
+//
+// This allows implementing https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find or similar APIs.
+func (db *indexDB) SearchTagValueSuffixes(tr TimeRange, tagKey, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int, deadline uint64) ([]string, error) {
+	// TODO: cache results?
+
+	tvss := make(map[string]struct{})
+	is := db.getIndexSearch(deadline)
+	err := is.searchTagValueSuffixesForTimeRange(tvss, tr, tagKey, tagValuePrefix, delimiter, maxTagValueSuffixes)
+	db.putIndexSearch(is)
+	if err != nil {
+		return nil, err
+	}
+	ok := db.doExtDB(func(extDB *indexDB) {
+		is := extDB.getIndexSearch(deadline)
+		err = is.searchTagValueSuffixesForTimeRange(tvss, tr, tagKey, tagValuePrefix, delimiter, maxTagValueSuffixes)
+		extDB.putIndexSearch(is)
+	})
+	if ok && err != nil {
+		return nil, err
+	}
+
+	suffixes := make([]string, 0, len(tvss))
+	for suffix := range tvss {
+		// Do not skip empty suffixes, since they may represent leaf tag values.
+		suffixes = append(suffixes, suffix)
+	}
+	// Do not sort suffixes, since they must be sorted by vmselect.
+	return suffixes, nil
+}
+
+func (is *indexSearch) searchTagValueSuffixesForTimeRange(tvss map[string]struct{}, tr TimeRange, tagKey, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int) error {
+	minDate := uint64(tr.MinTimestamp) / msecPerDay
+	maxDate := uint64(tr.MaxTimestamp) / msecPerDay
+	if maxDate-minDate > maxDaysForDateMetricIDs {
+		return is.searchTagValueSuffixesAll(tvss, tagKey, tagValuePrefix, delimiter, maxTagValueSuffixes)
+	}
+	// Query over multiple days in parallel.
+	var wg sync.WaitGroup
+	var errGlobal error
+	var mu sync.Mutex // protects tvss + errGlobal from concurrent access below.
+	for minDate <= maxDate {
+		wg.Add(1)
+		go func(date uint64) {
+			defer wg.Done()
+			tvssLocal := make(map[string]struct{})
+			isLocal := is.db.getIndexSearch(is.deadline)
+			defer is.db.putIndexSearch(isLocal)
+			err := isLocal.searchTagValueSuffixesForDate(tvssLocal, date, tagKey, tagValuePrefix, delimiter, maxTagValueSuffixes)
+			mu.Lock()
+			defer mu.Unlock()
+			if errGlobal != nil {
+				return
+			}
+			if err != nil {
+				errGlobal = err
+				return
+			}
+			for k := range tvssLocal {
+				tvss[k] = struct{}{}
+			}
+		}(minDate)
+		minDate++
+	}
+	wg.Wait()
+	return errGlobal
+}
+
+func (is *indexSearch) searchTagValueSuffixesAll(tvss map[string]struct{}, tagKey, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int) error {
+	kb := &is.kb
+	nsPrefix := byte(nsPrefixTagToMetricIDs)
+	kb.B = is.marshalCommonPrefix(kb.B[:0], nsPrefix)
+	kb.B = marshalTagValue(kb.B, tagKey)
+	kb.B = marshalTagValue(kb.B, tagValuePrefix)
+	kb.B = kb.B[:len(kb.B)-1] // remove tagSeparatorChar from the end of kb.B
+	prefix := append([]byte(nil), kb.B...)
+	return is.searchTagValueSuffixesForPrefix(tvss, nsPrefix, prefix, tagValuePrefix, delimiter, maxTagValueSuffixes)
+}
+
+func (is *indexSearch) searchTagValueSuffixesForDate(tvss map[string]struct{}, date uint64, tagKey, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int) error {
+	nsPrefix := byte(nsPrefixDateTagToMetricIDs)
+	kb := &is.kb
+	kb.B = is.marshalCommonPrefix(kb.B[:0], nsPrefix)
+	kb.B = encoding.MarshalUint64(kb.B, date)
+	kb.B = marshalTagValue(kb.B, tagKey)
+	kb.B = marshalTagValue(kb.B, tagValuePrefix)
+	kb.B = kb.B[:len(kb.B)-1] // remove tagSeparatorChar from the end of kb.B
+	prefix := append([]byte(nil), kb.B...)
+	return is.searchTagValueSuffixesForPrefix(tvss, nsPrefix, prefix, tagValuePrefix, delimiter, maxTagValueSuffixes)
+}
+
+func (is *indexSearch) searchTagValueSuffixesForPrefix(tvss map[string]struct{}, nsPrefix byte, prefix, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int) error {
+	kb := &is.kb
+	ts := &is.ts
+	mp := &is.mp
+	mp.Reset()
+	dmis := is.db.getDeletedMetricIDs()
+	loopsPaceLimiter := 0
+	ts.Seek(prefix)
+	for len(tvss) < maxTagValueSuffixes && ts.NextItem() {
+		if loopsPaceLimiter&paceLimiterFastIterationsMask == 0 {
+			if err := checkSearchDeadlineAndPace(is.deadline); err != nil {
+				return err
+			}
+		}
+		loopsPaceLimiter++
+		item := ts.Item
+		if !bytes.HasPrefix(item, prefix) {
+			break
+		}
+		if err := mp.Init(item, nsPrefix); err != nil {
+			return err
+		}
+		if mp.IsDeletedTag(dmis) {
+			continue
+		}
+		tagValue := mp.Tag.Value
+		if !bytes.HasPrefix(tagValue, tagValuePrefix) {
+			continue
+		}
+		suffix := tagValue[len(tagValuePrefix):]
+		n := bytes.IndexByte(suffix, delimiter)
+		if n < 0 {
+			// Found leaf tag value that doesn't have delimiters after the given tagValuePrefix.
+			tvss[string(suffix)] = struct{}{}
+			continue
+		}
+		// Found non-leaf tag value. Extract suffix that end with the given delimiter.
+		suffix = suffix[:n+1]
+		tvss[string(suffix)] = struct{}{}
+		if suffix[len(suffix)-1] == 255 {
+			continue
+		}
+		// Search for the next suffix
+		suffix[len(suffix)-1]++
+		kb.B = append(kb.B[:0], prefix...)
+		kb.B = marshalTagValue(kb.B, suffix)
+		kb.B = kb.B[:len(kb.B)-1] // remove tagSeparatorChar
+		ts.Seek(kb.B)
+	}
+	if err := ts.Error(); err != nil {
+		return fmt.Errorf("error when searching for tag value sufixes for prefix %q: %w", prefix, err)
+	}
+	return nil
+}
+
 // GetSeriesCount returns the approximate number of unique timeseries in the db.
 //
 // It includes the deleted series too and may count the same series
--- a/lib/storage/storage.go
+++ b/lib/storage/storage.go
@ -929,6 +929,13 @@ func (s *Storage) SearchTagValues(tagKey []byte, maxTagValues int, deadline uint
 	return s.idb().SearchTagValues(tagKey, maxTagValues, deadline)
 }

+// SearchTagValueSuffixes returns all the tag value suffixes for the given tagKey and tagValuePrefix on the given tr.
+//
+// This allows implementing https://graphite-api.readthedocs.io/en/latest/api.html#metrics-find or similar APIs.
+func (s *Storage) SearchTagValueSuffixes(tr TimeRange, tagKey, tagValuePrefix []byte, delimiter byte, maxTagValueSuffixes int, deadline uint64) ([]string, error) {
+	return s.idb().SearchTagValueSuffixes(tr, tagKey, tagValuePrefix, delimiter, maxTagValueSuffixes, deadline)
+}
+
 // SearchTagEntries returns a list of (tagName -> tagValues)
 func (s *Storage) SearchTagEntries(maxTagKeys, maxTagValues int, deadline uint64) ([]TagEntry, error) {
 	idb := s.idb()