Merge release-3.0 into main

docs/querying/api.md

@@ -433,18 +433,40 @@ URL query parameters:
   series from which to read the label values. Optional.
 - `limit=<number>`: Maximum number of returned series. Optional. 0 means disabled.
 
-
 The `data` section of the JSON response is a list of string label values.
 
-This example queries for all label values for the `job` label:
+This example queries for all label values for the `http_status_code` label:
 
 ```json
-$ curl http://localhost:9090/api/v1/label/job/values
+$ curl http://localhost:9090/api/v1/label/http_status_code/values
 {
    "status" : "success",
    "data" : [
-      "node",
+      "200",
-      "prometheus"
+      "504"
+   ]
+}
+```
+
+Label names can optionally be encoded using the Values Escaping method, and is necessary if a name includes the `/` character. To encode a name in this way:
+
+* Prepend the label with `U__`.
+* Letters, numbers, and colons appear as-is.
+* Convert single underscores to double underscores.
+* For all other characters, use the UTF-8 codepoint as a hex integer, surrounded
+  by underscores.  So ` ` becomes `_20_` and a `.` becomes `_2e_`.
+
+ More information about text escaping can be found in the original UTF-8 [Proposal document](https://github.com/prometheus/proposals/blob/main/proposals/2023-08-21-utf8.md#text-escaping).
+
+This example queries for all label values for the `http.status_code` label:
+
+```json
+$ curl http://localhost:9090/api/v1/label/U__http_2e_status_code/values
+{
+   "status" : "success",
+   "data" : [
+      "200",
+      "404"
    ]
 }
 ```

promql/engine.go

@@ -126,10 +126,7 @@ type QueryEngine interface {
 // QueryLogger is an interface that can be used to log all the queries logged
 // by the engine.
 type QueryLogger interface {
-	Error(msg string, args ...any)
+	Log(context.Context, slog.Level, string, ...any)
-	Info(msg string, args ...any)
-	Debug(msg string, args ...any)
-	Warn(msg string, args ...any)
 	With(args ...any)
 	Close() error
 }
@@ -637,20 +634,20 @@ func (ng *Engine) exec(ctx context.Context, q *query) (v parser.Value, ws annota
 				// The step provided by the user is in seconds.
 				params["step"] = int64(eq.Interval / (time.Second / time.Nanosecond))
 			}
-			l.With("params", params)
+			f := []interface{}{"params", params}
 			if err != nil {
-				l.With("error", err)
+				f = append(f, "error", err)
 			}
-			l.With("stats", stats.NewQueryStats(q.Stats()))
+			f = append(f, "stats", stats.NewQueryStats(q.Stats()))
 			if span := trace.SpanFromContext(ctx); span != nil {
-				l.With("spanID", span.SpanContext().SpanID())
+				f = append(f, "spanID", span.SpanContext().SpanID())
 			}
 			if origin := ctx.Value(QueryOrigin{}); origin != nil {
 				for k, v := range origin.(map[string]interface{}) {
-					l.With(k, v)
+					f = append(f, k, v)
 				}
 			}
-			l.Info("promql query logged")
+			l.Log(context.Background(), slog.LevelInfo, "promql query logged", f...)
 			// TODO: @tjhop -- do we still need this metric/error log if logger doesn't return errors?
 			// ng.metrics.queryLogFailures.Inc()
 			// ng.logger.Error("can't log query", "err", err)
@@ -1524,7 +1521,7 @@ func (ev *evaluator) evalSubquery(ctx context.Context, subq *parser.SubqueryExpr
 	// Avoid double counting samples when running a subquery, those samples will be counted in later stage.
 	ev.samplesStats = ev.samplesStats.NewChild()
 	val, ws := ev.eval(ctx, subq)
-	// But do incorporate the peak from the subquery
+	// But do incorporate the peak from the subquery.
 	samplesStats.UpdatePeakFromSubquery(ev.samplesStats)
 	ev.samplesStats = samplesStats
 	mat := val.(Matrix)
@@ -1989,7 +1986,7 @@ func (ev *evaluator) eval(ctx context.Context, expr parser.Expr) (parser.Value,
 		// Start with the first timestamp after (ev.startTimestamp - offset - range)
 		// that is aligned with the step (multiple of 'newEv.interval').
 		newEv.startTimestamp = newEv.interval * ((ev.startTimestamp - offsetMillis - rangeMillis) / newEv.interval)
-		if newEv.startTimestamp < (ev.startTimestamp - offsetMillis - rangeMillis) {
+		if newEv.startTimestamp <= (ev.startTimestamp - offsetMillis - rangeMillis) {
 			newEv.startTimestamp += newEv.interval
 		}
 

promql/engine_test.go

@@ -17,6 +17,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"math"
 	"sort"
 	"strings"
@@ -1426,23 +1427,23 @@ load 10s
 		},
 		{
 			// The peak samples in memory is during the first evaluation:
-			//   - Subquery takes 22 samples, 11 for each bigmetric, but samples on the left bound won't be evaluated.
+			//   - Subquery takes 20 samples, 10 for each bigmetric.
 			//   - Result is calculated per series where the series samples is buffered, hence 10 more here.
 			//   - The result of two series is added before the last series buffer is discarded, so 2 more here.
-			//   Hence at peak it is 22 (subquery) + 10 (buffer of a series) + 2 (result from 2 series).
+			//   Hence at peak it is 20 (subquery) + 10 (buffer of a series) + 2 (result from 2 series).
 			// The subquery samples and the buffer is discarded before duplicating.
 			Query:      `rate(bigmetric[10s:1s] @ 10)`,
-			MaxSamples: 34,
+			MaxSamples: 32,
 			Start:      time.Unix(0, 0),
 			End:        time.Unix(10, 0),
 			Interval:   5 * time.Second,
 		},
 		{
 			// Here the reasoning is same as above. But LHS and RHS are done one after another.
-			// So while one of them takes 34 samples at peak, we need to hold the 2 sample
+			// So while one of them takes 32 samples at peak, we need to hold the 2 sample
 			// result of the other till then.
 			Query:      `rate(bigmetric[10s:1s] @ 10) + rate(bigmetric[10s:1s] @ 30)`,
-			MaxSamples: 36,
+			MaxSamples: 34,
 			Start:      time.Unix(0, 0),
 			End:        time.Unix(10, 0),
 			Interval:   5 * time.Second,
@@ -1450,28 +1451,28 @@ load 10s
 		{
 			// promql.Sample as above but with only 1 part as step invariant.
 			// Here the peak is caused by the non-step invariant part as it touches more time range.
-			// Hence at peak it is 2*21 (subquery from 0s to 20s)
+			// Hence at peak it is 2*20 (subquery from 0s to 20s)
 			//                     + 10 (buffer of a series per evaluation)
 			//                     + 6 (result from 2 series at 3 eval times).
 			Query:      `rate(bigmetric[10s:1s]) + rate(bigmetric[10s:1s] @ 30)`,
-			MaxSamples: 58,
+			MaxSamples: 56,
 			Start:      time.Unix(10, 0),
 			End:        time.Unix(20, 0),
 			Interval:   5 * time.Second,
 		},
 		{
 			// Nested subquery.
-			// We saw that innermost rate takes 34 samples which is still the peak
+			// We saw that innermost rate takes 32 samples which is still the peak
 			// since the other two subqueries just duplicate the result.
-			Query:      `rate(rate(bigmetric[10s:1s] @ 10)[100s:25s] @ 1000)[100s:20s] @ 2000`,
+			Query:      `rate(rate(bigmetric[10:1s] @ 10)[100s:25s] @ 1000)[100s:20s] @ 2000`,
-			MaxSamples: 34,
+			MaxSamples: 32,
 			Start:      time.Unix(10, 0),
 		},
 		{
 			// Nested subquery.
-			// Now the outermost subquery produces more samples than inner most rate.
+			// Now the outermost subquery produces more samples than innermost rate.
 			Query:      `rate(rate(bigmetric[10s:1s] @ 10)[100s:25s] @ 1000)[17s:1s] @ 2000`,
-			MaxSamples: 36,
+			MaxSamples: 34,
 			Start:      time.Unix(10, 0),
 		},
 	}
@@ -1616,6 +1617,19 @@ load 1ms
 		}, {
 			query: "metric[100s:25s] @ 300",
 			start: 100,
+			result: promql.Matrix{
+				promql.Series{
+					Floats: []promql.FPoint{{F: 22, T: 225000}, {F: 25, T: 250000}, {F: 27, T: 275000}, {F: 30, T: 300000}},
+					Metric: lbls1,
+				},
+				promql.Series{
+					Floats: []promql.FPoint{{F: 44, T: 225000}, {F: 50, T: 250000}, {F: 54, T: 275000}, {F: 60, T: 300000}},
+					Metric: lbls2,
+				},
+			},
+		}, {
+			query: "metric[100s1ms:25s] @ 300", // Add 1ms to the range to see the legacy behavior of the previous test.
+			start: 100,
 			result: promql.Matrix{
 				promql.Series{
 					Floats: []promql.FPoint{{F: 20, T: 200000}, {F: 22, T: 225000}, {F: 25, T: 250000}, {F: 27, T: 275000}, {F: 30, T: 300000}},
@@ -1629,6 +1643,15 @@ load 1ms
 		}, {
 			query: "metric_neg[50s:25s] @ 0",
 			start: 100,
+			result: promql.Matrix{
+				promql.Series{
+					Floats: []promql.FPoint{{F: 26, T: -25000}, {F: 1, T: 0}},
+					Metric: lblsneg,
+				},
+			},
+		}, {
+			query: "metric_neg[50s1ms:25s] @ 0", // Add 1ms to the range to see the legacy behavior of the previous test.
+			start: 100,
 			result: promql.Matrix{
 				promql.Series{
 					Floats: []promql.FPoint{{F: 51, T: -50000}, {F: 26, T: -25000}, {F: 1, T: 0}},
@@ -1638,6 +1661,15 @@ load 1ms
 		}, {
 			query: "metric_neg[50s:25s] @ -100",
 			start: 100,
+			result: promql.Matrix{
+				promql.Series{
+					Floats: []promql.FPoint{{F: 126, T: -125000}, {F: 101, T: -100000}},
+					Metric: lblsneg,
+				},
+			},
+		}, {
+			query: "metric_neg[50s1ms:25s] @ -100", // Add 1ms to the range to see the legacy behavior of the previous test.
+			start: 100,
 			result: promql.Matrix{
 				promql.Series{
 					Floats: []promql.FPoint{{F: 151, T: -150000}, {F: 126, T: -125000}, {F: 101, T: -100000}},
@@ -1645,7 +1677,7 @@ load 1ms
 				},
 			},
 		}, {
-			query: `metric_ms[100ms:25ms] @ 2.345`,
+			query: `metric_ms[101ms:25ms] @ 2.345`,
 			start: 100,
 			result: promql.Matrix{
 				promql.Series{
@@ -1830,7 +1862,7 @@ func TestSubquerySelector(t *testing.T) {
 						nil,
 						promql.Matrix{
 							promql.Series{
-								Floats: []promql.FPoint{{F: 2, T: 10000}, {F: 2, T: 15000}, {F: 2, T: 20000}, {F: 2, T: 25000}, {F: 2, T: 30000}},
+								Floats: []promql.FPoint{{F: 2, T: 15000}, {F: 2, T: 20000}, {F: 2, T: 25000}, {F: 2, T: 30000}},
 								Metric: labels.FromStrings("__name__", "metric"),
 							},
 						},
@@ -1877,6 +1909,20 @@ func TestSubquerySelector(t *testing.T) {
 			cases: []caseType{
 				{ // Normal selector.
 					Query: `http_requests{group=~"pro.*",instance="0"}[30s:10s]`,
+					Result: promql.Result{
+						nil,
+						promql.Matrix{
+							promql.Series{
+								Floats: []promql.FPoint{{F: 10000, T: 10000000}, {F: 100, T: 10010000}, {F: 130, T: 10020000}},
+								Metric: labels.FromStrings("__name__", "http_requests", "job", "api-server", "instance", "0", "group", "production"),
+							},
+						},
+						nil,
+					},
+					Start: time.Unix(10020, 0),
+				},
+				{ // Normal selector. Add 1ms to the range to see the legacy behavior of the previous test.
+					Query: `http_requests{group=~"pro.*",instance="0"}[30s1ms:10s]`,
 					Result: promql.Result{
 						nil,
 						promql.Matrix{
@@ -1919,6 +1965,36 @@ func TestSubquerySelector(t *testing.T) {
 				},
 				{
 					Query: `rate(http_requests[1m])[15s:5s]`,
+					Result: promql.Result{
+						nil,
+						promql.Matrix{
+							promql.Series{
+								Floats:   []promql.FPoint{{F: 3, T: 7990000}, {F: 3, T: 7995000}, {F: 3, T: 8000000}},
+								Metric:   labels.FromStrings("job", "api-server", "instance", "0", "group", "canary"),
+								DropName: true,
+							},
+							promql.Series{
+								Floats:   []promql.FPoint{{F: 4, T: 7990000}, {F: 4, T: 7995000}, {F: 4, T: 8000000}},
+								Metric:   labels.FromStrings("job", "api-server", "instance", "1", "group", "canary"),
+								DropName: true,
+							},
+							promql.Series{
+								Floats:   []promql.FPoint{{F: 1, T: 7990000}, {F: 1, T: 7995000}, {F: 1, T: 8000000}},
+								Metric:   labels.FromStrings("job", "api-server", "instance", "0", "group", "production"),
+								DropName: true,
+							},
+							promql.Series{
+								Floats:   []promql.FPoint{{F: 2, T: 7990000}, {F: 2, T: 7995000}, {F: 2, T: 8000000}},
+								Metric:   labels.FromStrings("job", "api-server", "instance", "1", "group", "production"),
+								DropName: true,
+							},
+						},
+						nil,
+					},
+					Start: time.Unix(8000, 0),
+				},
+				{
+					Query: `rate(http_requests[1m])[15s1ms:5s]`, // Add 1ms to the range to see the legacy behavior of the previous test.
 					Result: promql.Result{
 						nil,
 						promql.Matrix{
@@ -1949,6 +2025,35 @@ func TestSubquerySelector(t *testing.T) {
 				},
 				{
 					Query: `sum(http_requests{group=~"pro.*"})[30s:10s]`,
+					Result: promql.Result{
+						nil,
+						promql.Matrix{
+							promql.Series{
+								Floats: []promql.FPoint{{F: 300, T: 100000}, {F: 330, T: 110000}, {F: 360, T: 120000}},
+								Metric: labels.EmptyLabels(),
+							},
+						},
+						nil,
+					},
+					Start: time.Unix(120, 0),
+				},
+				{
+					Query: `sum(http_requests{group=~"pro.*"})[30s:10s]`,
+					Result: promql.Result{
+						nil,
+						promql.Matrix{
+							promql.Series{
+								Floats: []promql.FPoint{{F: 300, T: 100000}, {F: 330, T: 110000}, {F: 360, T: 120000}},
+								Metric: labels.EmptyLabels(),
+							},
+						},
+						nil,
+					},
+					Start: time.Unix(121, 0), // 1s later doesn't change the result.
+				},
+				{
+					// Add 1ms to the range to see the legacy behavior of the previous test.
+					Query: `sum(http_requests{group=~"pro.*"})[30s1ms:10s]`,
 					Result: promql.Result{
 						nil,
 						promql.Matrix{
@@ -1963,6 +2068,20 @@ func TestSubquerySelector(t *testing.T) {
 				},
 				{
 					Query: `sum(http_requests)[40s:10s]`,
+					Result: promql.Result{
+						nil,
+						promql.Matrix{
+							promql.Series{
+								Floats: []promql.FPoint{{F: 900, T: 90000}, {F: 1000, T: 100000}, {F: 1100, T: 110000}, {F: 1200, T: 120000}},
+								Metric: labels.EmptyLabels(),
+							},
+						},
+						nil,
+					},
+					Start: time.Unix(120, 0),
+				},
+				{
+					Query: `sum(http_requests)[40s1ms:10s]`, // Add 1ms to the range to see the legacy behavior of the previous test.
 					Result: promql.Result{
 						nil,
 						promql.Matrix{
@@ -1977,6 +2096,21 @@ func TestSubquerySelector(t *testing.T) {
 				},
 				{
 					Query: `(sum(http_requests{group=~"p.*"})+sum(http_requests{group=~"c.*"}))[20s:5s]`,
+					Result: promql.Result{
+						nil,
+						promql.Matrix{
+							promql.Series{
+								Floats: []promql.FPoint{{F: 1000, T: 105000}, {F: 1100, T: 110000}, {F: 1100, T: 115000}, {F: 1200, T: 120000}},
+								Metric: labels.EmptyLabels(),
+							},
+						},
+						nil,
+					},
+					Start: time.Unix(120, 0),
+				},
+				{
+					// Add 1ms to the range to see the legacy behavior of the previous test.
+					Query: `(sum(http_requests{group=~"p.*"})+sum(http_requests{group=~"c.*"}))[20s1ms:5s]`,
 					Result: promql.Result{
 						nil,
 						promql.Matrix{
@@ -2034,31 +2168,10 @@ func (f *FakeQueryLogger) Close() error {
 }
 
 // It implements the promql.QueryLogger interface.
-func (f *FakeQueryLogger) Info(msg string, args ...any) {
+func (f *FakeQueryLogger) Log(ctx context.Context, level slog.Level, msg string, args ...any) {
-	log := append([]any{msg}, args...)
+	// Test usage only really cares about existence of keyvals passed in
-	log = append(log, f.attrs...)
+	// via args, just append in the log message before handling the
-	f.attrs = f.attrs[:0]
+	// provided args and any embedded kvs added via `.With()` on f.attrs.
-	f.logs = append(f.logs, log...)
-}
-
-// It implements the promql.QueryLogger interface.
-func (f *FakeQueryLogger) Error(msg string, args ...any) {
-	log := append([]any{msg}, args...)
-	log = append(log, f.attrs...)
-	f.attrs = f.attrs[:0]
-	f.logs = append(f.logs, log...)
-}
-
-// It implements the promql.QueryLogger interface.
-func (f *FakeQueryLogger) Warn(msg string, args ...any) {
-	log := append([]any{msg}, args...)
-	log = append(log, f.attrs...)
-	f.attrs = f.attrs[:0]
-	f.logs = append(f.logs, log...)
-}
-
-// It implements the promql.QueryLogger interface.
-func (f *FakeQueryLogger) Debug(msg string, args ...any) {
 	log := append([]any{msg}, args...)
 	log = append(log, f.attrs...)
 	f.attrs = f.attrs[:0]

promql/parser/generated_parser.y

@@ -667,10 +667,16 @@ label_set_list  : label_set_list COMMA label_set_item
 
 label_set_item  : IDENTIFIER EQL STRING
                         { $$ = labels.Label{Name: $1.Val, Value: yylex.(*parser).unquoteString($3.Val) } }
+                | string_identifier EQL STRING
+                        { $$ = labels.Label{Name: $1.Val, Value: yylex.(*parser).unquoteString($3.Val) } }
                 | IDENTIFIER EQL error
                         { yylex.(*parser).unexpected("label set", "string"); $$ = labels.Label{}}
+                | string_identifier EQL error
+                        { yylex.(*parser).unexpected("label set", "string"); $$ = labels.Label{}}
                 | IDENTIFIER error
                         { yylex.(*parser).unexpected("label set", "\"=\""); $$ = labels.Label{}}
+                | string_identifier error
+                        { yylex.(*parser).unexpected("label set", "\"=\""); $$ = labels.Label{}}
                 | error
                         { yylex.(*parser).unexpected("label set", "identifier or \"}\""); $$ = labels.Label{} }
                 ;

scrape/scrape.go

@@ -1421,7 +1421,7 @@ func (sl *scrapeLoop) scrapeAndReport(last, appendTime time.Time, errc chan<- er
 		sl.l.Debug("Scrape failed", "err", scrapeErr)
 		sl.scrapeFailureLoggerMtx.RLock()
 		if sl.scrapeFailureLogger != nil {
-			sl.scrapeFailureLogger.Error(scrapeErr.Error())
+			sl.scrapeFailureLogger.Log(context.Background(), slog.LevelError, scrapeErr.Error())
 		}
 		sl.scrapeFailureLoggerMtx.RUnlock()
 		if errc != nil {

util/logging/file.go

@@ -14,6 +14,7 @@
 package logging
 
 import (
+	"context"
 	"fmt"
 	"log/slog"
 	"os"
@@ -57,26 +58,8 @@ func (l *JSONFileLogger) With(args ...any) {
 	l.logger = l.logger.With(args...)
 }
 
-// Info calls the `Info()` method on the underlying `log/slog.Logger` with the
+// Log calls the `Log()` method on the underlying `log/slog.Logger` with the
 // provided msg and args. It implements the promql.QueryLogger interface.
-func (l *JSONFileLogger) Info(msg string, args ...any) {
+func (l *JSONFileLogger) Log(ctx context.Context, level slog.Level, msg string, args ...any) {
-	l.logger.Info(msg, args...)
+	l.logger.Log(ctx, level, msg, args...)
-}
-
-// Error calls the `Error()` method on the underlying `log/slog.Logger` with the
-// provided msg and args. It implements the promql.QueryLogger interface.
-func (l *JSONFileLogger) Error(msg string, args ...any) {
-	l.logger.Error(msg, args...)
-}
-
-// Debug calls the `Debug()` method on the underlying `log/slog.Logger` with the
-// provided msg and args. It implements the promql.QueryLogger interface.
-func (l *JSONFileLogger) Debug(msg string, args ...any) {
-	l.logger.Debug(msg, args...)
-}
-
-// Warn calls the `Warn()` method on the underlying `log/slog.Logger` with the
-// provided msg and args. It implements the promql.QueryLogger interface.
-func (l *JSONFileLogger) Warn(msg string, args ...any) {
-	l.logger.Warn(msg, args...)
 }

util/logging/file_test.go

@@ -14,6 +14,8 @@
 package logging
 
 import (
+	"context"
+	"log/slog"
 	"os"
 	"strings"
 	"testing"
@@ -34,7 +36,7 @@ func TestJSONFileLogger_basic(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, l, "logger can't be nil")
 
-	l.Info("test", "hello", "world")
+	l.Log(context.Background(), slog.LevelInfo, "test", "hello", "world")
 	require.NoError(t, err)
 	r := make([]byte, 1024)
 	_, err = f.Read(r)
@@ -64,14 +66,14 @@ func TestJSONFileLogger_parallel(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, l, "logger can't be nil")
 
-	l.Info("test", "hello", "world")
+	l.Log(context.Background(), slog.LevelInfo, "test", "hello", "world")
 	require.NoError(t, err)
 
 	l2, err := NewJSONFileLogger(f.Name())
 	require.NoError(t, err)
 	require.NotNil(t, l, "logger can't be nil")
 
-	l2.Info("test", "hello", "world")
+	l2.Log(context.Background(), slog.LevelInfo, "test", "hello", "world")
 	require.NoError(t, err)
 
 	err = l.Close()

web/api/v1/api.go

@@ -744,7 +744,12 @@ func (api *API) labelValues(r *http.Request) (result apiFuncResult) {
 	ctx := r.Context()
 	name := route.Param(ctx, "name")
 
-	if !model.LabelNameRE.MatchString(name) {
+	if strings.HasPrefix(name, "U__") {
+		name = model.UnescapeName(name, model.ValueEncodingEscaping)
+	}
+
+	label := model.LabelName(name)
+	if !label.IsValid() {
 		return apiFuncResult{nil, &apiError{errorBadData, fmt.Errorf("invalid label name: %q", name)}, nil, nil}
 	}
 

web/api/v1/api_test.go

@@ -387,6 +387,8 @@ func TestEndpoints(t *testing.T) {
 			test_metric4{foo="bar", dup="1"} 1+0x100
 			test_metric4{foo="boo", dup="1"} 1+0x100
 			test_metric4{foo="boo"} 1+0x100
+			test_metric5{"host.name"="localhost"} 1+0x100
+			test_metric5{"junk\n{},=:  chars"="bar"} 1+0x100
 	`)
 	t.Cleanup(func() { storage.Close() })
 
@@ -1117,6 +1119,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 		metadata              []targetMetadata
 		exemplars             []exemplar.QueryResult
 		zeroFunc              func(interface{})
+		nameValidationScheme  model.ValidationScheme
 	}
 
 	rulesZeroFunc := func(i interface{}) {
@@ -3004,6 +3007,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"test_metric2",
 					"test_metric3",
 					"test_metric4",
+					"test_metric5",
 				},
 			},
 			{
@@ -3016,13 +3020,36 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"boo",
 				},
 			},
-			// Bad name parameter.
+			// Bad name parameter for legacy validation.
 			{
 				endpoint: api.labelValues,
 				params: map[string]string{
-					"name": "not!!!allowed",
+					"name": "host.name",
+				},
+				nameValidationScheme: model.LegacyValidation,
+				errType:              errorBadData,
+			},
+			// Valid utf8 name parameter for utf8 validation.
+			{
+				endpoint: api.labelValues,
+				params: map[string]string{
+					"name": "host.name",
+				},
+				nameValidationScheme: model.UTF8Validation,
+				response: []string{
+					"localhost",
+				},
+			},
+			// Valid escaped utf8 name parameter for utf8 validation.
+			{
+				endpoint: api.labelValues,
+				params: map[string]string{
+					"name": "U__junk_0a__7b__7d__2c__3d_:_20__20_chars",
+				},
+				nameValidationScheme: model.UTF8Validation,
+				response: []string{
+					"bar",
 				},
-				errType: errorBadData,
 			},
 			// Start and end before LabelValues starts.
 			{
@@ -3258,15 +3285,15 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"name": "__name__",
 				},
 				query: url.Values{
-					"limit": []string{"4"},
+					"limit": []string{"5"},
 				},
-				responseLen:   4, // API does not specify which particular values will come back.
+				responseLen:   5, // API does not specify which particular values will come back.
 				warningsCount: 0, // No warnings if limit isn't exceeded.
 			},
 			// Label names.
 			{
 				endpoint: api.labelNames,
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 			// Start and end before Label names starts.
 			{
@@ -3284,7 +3311,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"start": []string{"1"},
 					"end":   []string{"100"},
 				},
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 			// Start before Label names, end within Label names.
 			{
@@ -3293,7 +3320,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"start": []string{"-1"},
 					"end":   []string{"10"},
 				},
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 
 			// Start before Label names starts, end after Label names ends.
@@ -3303,7 +3330,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"start": []string{"-1"},
 					"end":   []string{"100000"},
 				},
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 			// Start with bad data for Label names, end within Label names.
 			{
@@ -3321,7 +3348,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 					"start": []string{"1"},
 					"end":   []string{"1000000006"},
 				},
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 			// Start and end after Label names ends.
 			{
@@ -3338,7 +3365,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 				query: url.Values{
 					"start": []string{"4"},
 				},
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 			// Only provide End within Label names, don't provide a start time.
 			{
@@ -3346,7 +3373,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 				query: url.Values{
 					"end": []string{"20"},
 				},
-				response: []string{"__name__", "dup", "foo"},
+				response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=:  chars"},
 			},
 			// Label names with bad matchers.
 			{
@@ -3414,9 +3441,9 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 			{
 				endpoint: api.labelNames,
 				query: url.Values{
-					"limit": []string{"3"},
+					"limit": []string{"5"},
 				},
-				responseLen:   3, // API does not specify which particular values will come back.
+				responseLen:   5, // API does not specify which particular values will come back.
 				warningsCount: 0, // No warnings if limit isn't exceeded.
 			},
 		}...)
@@ -3452,6 +3479,8 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 						ctx = route.WithParam(ctx, p, v)
 					}
 
+					model.NameValidationScheme = test.nameValidationScheme
+
 					req, err := request(method, test.query)
 					require.NoError(t, err)