some content negotiation!

cmd/prometheus/main.go

@@ -215,6 +215,10 @@ func (c *flagConfig) setFeatureListOptions(logger log.Logger) error {
 				config.DefaultConfig.GlobalConfig.ScrapeProtocols = config.DefaultProtoFirstScrapeProtocols
 				config.DefaultGlobalConfig.ScrapeProtocols = config.DefaultProtoFirstScrapeProtocols
 				level.Info(logger).Log("msg", "Experimental created timestamp zero ingestion enabled. Changed default scrape_protocols to prefer PrometheusProto format.", "global.scrape_protocols", fmt.Sprintf("%v", config.DefaultGlobalConfig.ScrapeProtocols))
+			case "utf8-names":
+				config.DefaultConfig.GlobalConfig.AllowUTF8Names = true
+				config.DefaultGlobalConfig.AllowUTF8Names = true
+				model.NameValidationScheme = model.UTF8Validation
 			case "":
 				continue
 			case "promql-at-modifier", "promql-negative-offset":
@@ -429,7 +433,7 @@ func main() {
 	a.Flag("scrape.discovery-reload-interval", "Interval used by scrape manager to throttle target groups updates.").
 		Hidden().Default("5s").SetValue(&cfg.scrape.DiscoveryReloadInterval)
 
-	a.Flag("enable-feature", "Comma separated feature names to enable. Valid options: agent, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-at-modifier, promql-negative-offset, promql-per-step-stats, promql-experimental-functions, remote-write-receiver (DEPRECATED), extra-scrape-metrics, new-service-discovery-manager, auto-gomaxprocs, no-default-scrape-port, native-histograms, otlp-write-receiver. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details.").
+	a.Flag("enable-feature", "Comma separated feature names to enable. Valid options: agent, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-at-modifier, promql-negative-offset, promql-per-step-stats, promql-experimental-functions, remote-write-receiver (DEPRECATED), extra-scrape-metrics, new-service-discovery-manager, auto-gomaxprocs, no-default-scrape-port, native-histograms, otlp-write-receiver, utf8-names. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details.").
 		Default("").StringsVar(&cfg.featureList)
 
 	promlogflag.AddFlags(a, &cfg.promlogConfig)

cmd/promtool/metrics.go

@@ -102,6 +102,7 @@ func PushMetrics(url *url.URL, roundTripper http.RoundTripper, headers map[strin
 }
 
 func parseAndPushMetrics(client *remote.Client, data []byte, labels map[string]string) bool {
+	// XXXXX ok we need communication between this call (it should escape)
 	metricsData, err := fmtutil.MetricTextToWriteRequest(bytes.NewReader(data), labels)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "  FAILED:", err)
@@ -116,6 +117,7 @@ func parseAndPushMetrics(client *remote.Client, data []byte, labels map[string]s
 
 	// Encode the request body into snappy encoding.
 	compressed := snappy.Encode(nil, raw)
+	// XXXXXXXXX and this call to store (which sets the content headers)
 	err = client.Store(context.Background(), compressed, 0)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "  FAILED:", err)

config/config.go

@@ -421,6 +421,8 @@ type GlobalConfig struct {
 	// Keep no more than this many dropped targets per job.
 	// 0 means no limit.
 	KeepDroppedTargets uint `yaml:"keep_dropped_targets,omitempty"`
+	// Allow UTF8 Metric and Label Names
+	AllowUTF8Names bool `yaml:"utf8_names,omitempty"`
 }
 
 // ScrapeProtocol represents supported protocol for scraping metrics.
@@ -446,6 +448,7 @@ var (
 	PrometheusText0_0_4  ScrapeProtocol = "PrometheusText0.0.4"
 	OpenMetricsText0_0_1 ScrapeProtocol = "OpenMetricsText0.0.1"
 	OpenMetricsText1_0_0 ScrapeProtocol = "OpenMetricsText1.0.0"
+	UTF8NamesHeader      string         = "validchars=utf8"
 
 	ScrapeProtocolsHeaders = map[ScrapeProtocol]string{
 		PrometheusProto:      "application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited",
@@ -616,6 +619,8 @@ type ScrapeConfig struct {
 	// Keep no more than this many dropped targets per job.
 	// 0 means no limit.
 	KeepDroppedTargets uint `yaml:"keep_dropped_targets,omitempty"`
+	// Allow UTF8 Metric and Label Names
+	AllowUTF8Names bool `yaml:"utf8_names,omitempty"`
 
 	// We cannot do proper Go type embedding below as the parser will then parse
 	// values arbitrarily into the overflow maps of further-down types.

go.mod

@@ -212,3 +212,7 @@ exclude (
 	github.com/grpc-ecosystem/grpc-gateway v1.14.7
 	google.golang.org/api v0.30.0
 )
+
+replace github.com/prometheus/common => /home/owilliams/src/third_party/common
+
+replace github.com/prometheus/client_golang => /home/owilliams/src/grafana/client_golang

model/textparse/interface.go

@@ -85,6 +85,10 @@ func New(b []byte, contentType string, parseClassicHistograms bool) (Parser, err
 		return NewPromParser(b), nil
 	}
 
+	// XXXX looks like this could be a place to decide if UTF8 is ok?? or is this
+	// all about we need a global option ---- yeah I think prometheus is either
+	// utf8 on and some preferred escaping, or its utf8 off.  not per scrape target.
+	// In wihch case, nothing needs to change here.
 	mediaType, _, err := mime.ParseMediaType(contentType)
 	if err != nil {
 		return NewPromParser(b), err

model/textparse/openmetricsparse.go

@@ -26,7 +26,6 @@ import (
 
 	"github.com/prometheus/common/model"
 
-	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/model/exemplar"
 	"github.com/prometheus/prometheus/model/histogram"
 	"github.com/prometheus/prometheus/model/labels"

model/textparse/openmetricsparse_test.go

@@ -301,10 +301,10 @@ foo_total 17.0 1520879607.789 # {id="counter-test"} 5`
 }
 
 func TestUTF8OpenMetricsParse(t *testing.T) {
-	// model.NameValidationScheme = model.UTF8Validation
+	model.NameValidationScheme = model.UTF8Validation
-	// defer func(){
+	defer func(){
-	// 	model.NameValidationScheme = model.LegacyValidation
+		model.NameValidationScheme = model.LegacyValidation
-	// }()
+	}()
 
 	input := `# HELP "go.gc_duration_seconds" A summary of the GC invocation durations.
 # TYPE "go.gc_duration_seconds" summary
@@ -324,7 +324,7 @@ func TestUTF8OpenMetricsParse(t *testing.T) {
 		m       string
 		t       *int64
 		v       float64
-		typ     MetricType
+		typ     model.MetricType
 		help    string
 		unit    string
 		comment string
@@ -335,7 +335,7 @@ func TestUTF8OpenMetricsParse(t *testing.T) {
 			help: "A summary of the GC invocation durations.",
 		}, {
 			m:   "go.gc_duration_seconds",
-			typ: MetricTypeSummary,
+			typ: model.MetricTypeSummary,
 		}, {
 			m:    "go.gc_duration_seconds",
 			unit: "seconds",

model/textparse/promparse.go

@@ -28,7 +28,6 @@ import (
 
 	"github.com/prometheus/common/model"
 
-	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/model/exemplar"
 	"github.com/prometheus/prometheus/model/histogram"
 	"github.com/prometheus/prometheus/model/labels"

model/textparse/promparse_test.go

@@ -219,10 +219,10 @@ testmetric{label="\"bar\""} 1`
 }
 
 func TestUTF8PromParse(t *testing.T) {
-	// model.NameValidationScheme = model.UTF8Validation
+	model.NameValidationScheme = model.UTF8Validation
-	// defer func() {
+	defer func() {
-	// 	model.NameValidationScheme = model.LegacyValidation
+		model.NameValidationScheme = model.LegacyValidation
-	// }()
+	}()
 
 	input := `# HELP "go.gc_duration_seconds" A summary of the GC invocation durations.
 # 	TYPE "go.gc_duration_seconds" summary
@@ -242,7 +242,7 @@ func TestUTF8PromParse(t *testing.T) {
 		m       string
 		t       *int64
 		v       float64
-		typ     MetricType
+		typ     model.MetricType
 		help    string
 		comment string
 	}{
@@ -251,7 +251,7 @@ func TestUTF8PromParse(t *testing.T) {
 			help: "A summary of the GC invocation durations.",
 		}, {
 			m:   "go.gc_duration_seconds",
-			typ: MetricTypeSummary,
+			typ: model.MetricTypeSummary,
 		}, {
 			m:    `{"go.gc_duration_seconds",quantile="0"}`,
 			v:    4.9351e-05,
@@ -597,7 +597,7 @@ func BenchmarkParse(b *testing.B) {
 				for i := 0; i < b.N; i += promtestdataSampleCount {
 					decSamples := make(model.Vector, 0, 50)
 					sdec := expfmt.SampleDecoder{
-						Dec: expfmt.NewDecoder(bytes.NewReader(buf), expfmt.FmtText),
+						Dec: expfmt.NewDecoder(bytes.NewReader(buf), expfmt.FmtText_1_0_0),
 						Opts: &expfmt.DecodeOptions{
 							Timestamp: model.TimeFromUnixNano(0),
 						},

prompb/remote.pb.go

@@ -66,6 +66,9 @@ func (ReadRequest_ResponseType) EnumDescriptor() ([]byte, []int) {
 type WriteRequest struct {
 	Timeseries []TimeSeries     `protobuf:"bytes,1,rep,name=timeseries,proto3" json:"timeseries"`
 	Metadata   []MetricMetadata `protobuf:"bytes,3,rep,name=metadata,proto3" json:"metadata"`
+	// If true, metric names and labels can use the full UTF-8 character set.
+	// Otherwise, apply the legacy naming convention.
+	Utf8Names            bool     `protobuf:"varint,4,opt,name=utf8_names,json=utf8Names,proto3" json:"utf8_names,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -118,6 +121,13 @@ func (m *WriteRequest) GetMetadata() []MetricMetadata {
 	return nil
 }
 
+func (m *WriteRequest) GetUtf8Names() bool {
+	if m != nil {
+		return m.Utf8Names
+	}
+	return false
+}
+
 // ReadRequest represents a remote read request.
 type ReadRequest struct {
 	Queries []*Query `protobuf:"bytes,1,rep,name=queries,proto3" json:"queries,omitempty"`
@@ -420,38 +430,40 @@ func init() {
 func init() { proto.RegisterFile("remote.proto", fileDescriptor_eefc82927d57d89b) }
 
 var fileDescriptor_eefc82927d57d89b = []byte{
-	// 496 bytes of a gzipped FileDescriptorProto
+	// 517 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x53, 0xcd, 0x6e, 0xd3, 0x40,
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x53, 0xcb, 0x6e, 0xd3, 0x4c,
-	0x10, 0xee, 0x26, 0x69, 0x13, 0x8d, 0x43, 0x14, 0xb6, 0x2d, 0x09, 0x39, 0xa4, 0x91, 0xc5, 0x21,
+	0x14, 0xae, 0x93, 0xb4, 0xc9, 0x7f, 0x9c, 0x3f, 0x0a, 0xd3, 0x96, 0x84, 0x48, 0xa4, 0x91, 0xc5,
-	0x52, 0x51, 0x10, 0xa1, 0xe2, 0xd4, 0x03, 0x69, 0x89, 0x54, 0xa0, 0xe6, 0x67, 0x13, 0x04, 0x42,
+	0x22, 0x52, 0x51, 0x10, 0xa1, 0x42, 0x2c, 0xba, 0x20, 0x2d, 0x91, 0x0a, 0xd4, 0x05, 0xc6, 0x41,
-	0x48, 0xd6, 0xc6, 0x1e, 0x35, 0x16, 0xf5, 0x4f, 0x77, 0xd7, 0x52, 0xf3, 0x16, 0x3c, 0x13, 0xa7,
+	0x20, 0x84, 0x64, 0x4d, 0xec, 0x43, 0x63, 0x51, 0x5f, 0x3a, 0x33, 0x96, 0x9a, 0xa7, 0xe2, 0x1d,
-	0x9e, 0x10, 0x4f, 0x80, 0x50, 0x9e, 0x04, 0x79, 0x6d, 0x87, 0x2d, 0x5c, 0xb8, 0xad, 0xbf, 0x3f,
+	0x58, 0x75, 0x85, 0x78, 0x02, 0x84, 0xf2, 0x24, 0xc8, 0x63, 0x3b, 0x4c, 0x61, 0xc3, 0x6e, 0xfc,
-	0xcf, 0xcc, 0xce, 0x42, 0x53, 0x60, 0x18, 0x2b, 0x1c, 0x25, 0x22, 0x56, 0x31, 0x85, 0x44, 0xc4,
+	0xdd, 0x66, 0xce, 0xc5, 0xd0, 0xe4, 0x18, 0xc6, 0x12, 0x47, 0x09, 0x8f, 0x65, 0x4c, 0x20, 0xe1,
-	0x21, 0xaa, 0x25, 0xa6, 0xb2, 0x67, 0xa9, 0x55, 0x82, 0x32, 0x27, 0x7a, 0x7b, 0x17, 0xf1, 0x45,
+	0x71, 0x88, 0x72, 0x81, 0xa9, 0xe8, 0x99, 0x72, 0x99, 0xa0, 0xc8, 0x89, 0xde, 0xce, 0x79, 0x7c,
-	0xac, 0x8f, 0x8f, 0xb2, 0x53, 0x8e, 0xda, 0x5f, 0x09, 0x34, 0x3f, 0x88, 0x40, 0x21, 0xc3, 0xab,
+	0x1e, 0xab, 0xe3, 0x83, 0xec, 0x94, 0xa3, 0xd6, 0x17, 0x03, 0x9a, 0xef, 0x78, 0x20, 0x91, 0xe2,
-	0x14, 0xa5, 0xa2, 0xc7, 0x00, 0x2a, 0x08, 0x51, 0xa2, 0x08, 0x50, 0x76, 0xc9, 0xa0, 0x3a, 0xb4,
+	0x65, 0x8a, 0x42, 0x92, 0x43, 0x00, 0x19, 0x84, 0x28, 0x90, 0x07, 0x28, 0xba, 0xc6, 0xa0, 0x3a,
-	0xc6, 0xf7, 0x46, 0x7f, 0x42, 0x47, 0xf3, 0x20, 0xc4, 0x99, 0x66, 0x4f, 0x6a, 0x37, 0x3f, 0x0f,
+	0x34, 0xc7, 0xb7, 0x47, 0xbf, 0x43, 0x47, 0xb3, 0x20, 0x44, 0x47, 0xb1, 0x47, 0xb5, 0xeb, 0x1f,
-	0xb6, 0x98, 0xa1, 0xa7, 0xc7, 0xd0, 0x08, 0x51, 0x71, 0x9f, 0x2b, 0xde, 0xad, 0x6a, 0x6f, 0xcf,
+	0x7b, 0x1b, 0x54, 0xd3, 0x93, 0x43, 0x68, 0x84, 0x28, 0x99, 0xcf, 0x24, 0xeb, 0x56, 0x95, 0xb7,
-	0xf4, 0x3a, 0xa8, 0x44, 0xe0, 0x39, 0x85, 0xa2, 0xf0, 0x6f, 0x1c, 0x2f, 0x6b, 0x8d, 0x4a, 0xbb,
+	0xa7, 0x7b, 0x6d, 0x94, 0x3c, 0xf0, 0xec, 0x42, 0x51, 0xf8, 0xd7, 0x0e, 0x72, 0x17, 0x20, 0x95,
-	0x6a, 0x7f, 0x27, 0x60, 0x31, 0xe4, 0x7e, 0x59, 0xd1, 0x21, 0xd4, 0xaf, 0x52, 0xb3, 0x9c, 0xbb,
+	0x9f, 0x9e, 0xb8, 0x11, 0x0b, 0x51, 0x74, 0x6b, 0x03, 0x63, 0xd8, 0xa0, 0xff, 0x65, 0xc8, 0x59,
-	0x66, 0xe4, 0xbb, 0x14, 0xc5, 0x8a, 0x95, 0x0a, 0xfa, 0x19, 0x3a, 0xdc, 0xf3, 0x30, 0x51, 0xe8,
+	0x06, 0xbc, 0xa8, 0x35, 0x2a, 0xed, 0xaa, 0xf5, 0xcd, 0x00, 0x93, 0x22, 0xf3, 0xcb, 0x07, 0xef,
-	0xbb, 0x02, 0x65, 0x12, 0x47, 0x12, 0x5d, 0x3d, 0x86, 0x6e, 0x65, 0x50, 0x1d, 0xb6, 0xc6, 0x0f,
+	0x43, 0xfd, 0x32, 0xd5, 0x5f, 0x7b, 0x4b, 0xbf, 0xf1, 0x4d, 0x8a, 0x7c, 0x49, 0x4b, 0x05, 0xf9,
-	0x4c, 0xb3, 0xf1, 0x9b, 0x11, 0x2b, 0xd4, 0xf3, 0x55, 0x82, 0x6c, 0xbf, 0x0c, 0x31, 0x51, 0x69,
+	0x08, 0x1d, 0xe6, 0x79, 0x98, 0x48, 0xf4, 0x5d, 0x8e, 0x22, 0x89, 0x23, 0x81, 0xae, 0xea, 0x52,
-	0x1f, 0x41, 0xd3, 0x04, 0xa8, 0x05, 0xf5, 0xd9, 0xc4, 0x79, 0x7b, 0x3e, 0x9d, 0xb5, 0xb7, 0x68,
+	0xb7, 0x32, 0xa8, 0x0e, 0x5b, 0xe3, 0x7b, 0xba, 0x59, 0xbb, 0x66, 0x44, 0x0b, 0xf5, 0x6c, 0x99,
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+	0x20, 0xdd, 0x2d, 0x43, 0x74, 0x54, 0x58, 0x07, 0xd0, 0xd4, 0x01, 0x62, 0x42, 0xdd, 0x99, 0xd8,
-	0xff, 0xfa, 0xd5, 0xac, 0x4d, 0xec, 0x49, 0xe6, 0xe2, 0x9b, 0x28, 0xfa, 0x18, 0xea, 0x02, 0x65,
+	0xaf, 0x4f, 0xa7, 0x4e, 0x7b, 0x83, 0x74, 0x60, 0xdb, 0x99, 0xd1, 0xe9, 0xc4, 0x9e, 0x3e, 0x73,
-	0x7a, 0xa9, 0xca, 0x86, 0x3a, 0xff, 0x36, 0xa4, 0x79, 0x56, 0xea, 0xec, 0x6f, 0x04, 0xb6, 0x35,
+	0xdf, 0xbf, 0xa2, 0xee, 0xf1, 0xc9, 0xdb, 0xb3, 0x97, 0x4e, 0xdb, 0xb0, 0x26, 0x99, 0x8b, 0xad,
-	0x41, 0x1f, 0x02, 0x95, 0x8a, 0x0b, 0xe5, 0xea, 0xa9, 0x2b, 0x1e, 0x26, 0x6e, 0x98, 0xe5, 0x90,
+	0xa3, 0xc8, 0x43, 0xa8, 0x73, 0x14, 0xe9, 0x85, 0x2c, 0x0b, 0xea, 0xfc, 0x5d, 0x90, 0xe2, 0x69,
-	0x61, 0x95, 0xb5, 0x35, 0x33, 0x2f, 0x09, 0x47, 0xd2, 0x21, 0xb4, 0x31, 0xf2, 0x6f, 0x6b, 0x2b,
+	0xa9, 0xb3, 0xbe, 0x1a, 0xb0, 0xa9, 0x08, 0x72, 0x1f, 0x88, 0x90, 0x8c, 0x4b, 0x57, 0x0d, 0x45,
-	0x5a, 0xdb, 0xc2, 0xc8, 0x37, 0x95, 0x47, 0xd0, 0x08, 0xb9, 0xf2, 0x96, 0x28, 0x64, 0x71, 0x73,
+	0xb2, 0x30, 0x71, 0xc3, 0x2c, 0xc7, 0x18, 0x56, 0x69, 0x5b, 0x31, 0xb3, 0x92, 0xb0, 0x05, 0x19,
-	0x5d, 0xb3, 0xaa, 0x73, 0xbe, 0xc0, 0x4b, 0x27, 0x17, 0xb0, 0x8d, 0x92, 0x1e, 0xc2, 0xf6, 0x32,
+	0x42, 0x1b, 0x23, 0xff, 0xa6, 0xb6, 0xa2, 0xb4, 0x2d, 0x8c, 0x7c, 0x5d, 0x79, 0x00, 0x8d, 0x90,
-	0x88, 0x94, 0xec, 0xd6, 0x06, 0x64, 0x68, 0x8d, 0xf7, 0xff, 0x1e, 0xee, 0x59, 0x46, 0xb2, 0x5c,
+	0x49, 0x6f, 0x81, 0x5c, 0x14, 0x83, 0xed, 0xea, 0xaf, 0x3a, 0x65, 0x73, 0xbc, 0xb0, 0x73, 0x01,
-	0x63, 0x4f, 0xc1, 0x32, 0x9a, 0xa3, 0x4f, 0xff, 0x7f, 0xd3, 0xcc, 0x1d, 0xb3, 0xaf, 0x61, 0xf7,
+	0x5d, 0x2b, 0xc9, 0x3e, 0x6c, 0x2e, 0x82, 0x48, 0xe6, 0xb3, 0x34, 0xc7, 0xbb, 0x7f, 0x36, 0xf7,
-	0x74, 0x99, 0x46, 0x5f, 0xb2, 0xcb, 0x31, 0xa6, 0xfa, 0x0c, 0x5a, 0x5e, 0x0e, 0xbb, 0xb7, 0x22,
+	0x24, 0x23, 0x69, 0xae, 0xb1, 0xa6, 0x60, 0x6a, 0xc5, 0x91, 0xc7, 0xff, 0xbe, 0x88, 0xfa, 0x0a,
-	0xef, 0x9b, 0x91, 0x85, 0xb1, 0x48, 0xbd, 0xe3, 0x99, 0x9f, 0xf4, 0x00, 0xac, 0x6c, 0x8d, 0x56,
+	0x5a, 0x57, 0xb0, 0x7d, 0xbc, 0x48, 0xa3, 0xcf, 0xd9, 0x70, 0xb4, 0xae, 0x3e, 0x85, 0x96, 0x97,
-	0x6e, 0x10, 0xf9, 0x78, 0x5d, 0xcc, 0x09, 0x34, 0xf4, 0x22, 0x43, 0x4e, 0xf6, 0x6e, 0xd6, 0x7d,
+	0xc3, 0xee, 0x8d, 0xc8, 0x3b, 0x7a, 0x64, 0x61, 0x2c, 0x52, 0xff, 0xf7, 0xf4, 0x4f, 0xb2, 0x07,
-	0xf2, 0x63, 0xdd, 0x27, 0xbf, 0xd6, 0x7d, 0xf2, 0x69, 0x27, 0xcb, 0x4d, 0x16, 0x8b, 0x1d, 0xfd,
+	0x66, 0xb6, 0x46, 0x4b, 0x37, 0x88, 0x7c, 0xbc, 0x2a, 0xfa, 0x04, 0x0a, 0x7a, 0x9e, 0x21, 0x47,
-	0x92, 0x9e, 0xfc, 0x0e, 0x00, 0x00, 0xff, 0xff, 0x13, 0x18, 0x12, 0x0a, 0x88, 0x03, 0x00, 0x00,
+	0x3b, 0xd7, 0xab, 0xbe, 0xf1, 0x7d, 0xd5, 0x37, 0x7e, 0xae, 0xfa, 0xc6, 0x87, 0xad, 0x2c, 0x37,
+	0x99, 0xcf, 0xb7, 0xd4, 0x8f, 0xf6, 0xe8, 0x57, 0x00, 0x00, 0x00, 0xff, 0xff, 0xfe, 0x43, 0xa9,
+	0x4e, 0xa7, 0x03, 0x00, 0x00,
 }
 
 func (m *WriteRequest) Marshal() (dAtA []byte, err error) {
@@ -478,6 +490,16 @@ func (m *WriteRequest) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 		i -= len(m.XXX_unrecognized)
 		copy(dAtA[i:], m.XXX_unrecognized)
 	}
+	if m.Utf8Names {
+		i--
+		if m.Utf8Names {
+			dAtA[i] = 1
+		} else {
+			dAtA[i] = 0
+		}
+		i--
+		dAtA[i] = 0x20
+	}
 	if len(m.Metadata) > 0 {
 		for iNdEx := len(m.Metadata) - 1; iNdEx >= 0; iNdEx-- {
 			{
@@ -788,6 +810,9 @@ func (m *WriteRequest) Size() (n int) {
 			n += 1 + l + sovRemote(uint64(l))
 		}
 	}
+	if m.Utf8Names {
+		n += 2
+	}
 	if m.XXX_unrecognized != nil {
 		n += len(m.XXX_unrecognized)
 	}
@@ -1007,6 +1032,26 @@ func (m *WriteRequest) Unmarshal(dAtA []byte) error {
 				return err
 			}
 			iNdEx = postIndex
+		case 4:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Utf8Names", wireType)
+			}
+			var v int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowRemote
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				v |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			m.Utf8Names = bool(v != 0)
 		default:
 			iNdEx = preIndex
 			skippy, err := skipRemote(dAtA[iNdEx:])

prompb/remote.proto

@@ -25,6 +25,9 @@ message WriteRequest {
   // We reserve it to avoid any compatibility issues.
   reserved  2;
   repeated prometheus.MetricMetadata metadata = 3 [(gogoproto.nullable) = false];
+  // If true, metric names and labels can use the full UTF-8 character set.
+  // Otherwise, apply the legacy naming convention.
+  bool utf8_names = 4;
 }
 
 // ReadRequest represents a remote read request.

scrape/scrape.go

@@ -302,7 +302,7 @@ func (sp *scrapePool) reload(cfg *config.ScrapeConfig) error {
 				client:               sp.client,
 				timeout:              timeout,
 				bodySizeLimit:        bodySizeLimit,
-				acceptHeader:         acceptHeader(cfg.ScrapeProtocols),
+				acceptHeader:         acceptHeader(cfg.ScrapeProtocols, cfg.AllowUTF8Names),
 				acceptEncodingHeader: acceptEncodingHeader(enableCompression),
 			}
 			newLoop = sp.newLoop(scrapeLoopOptions{
@@ -429,7 +429,7 @@ func (sp *scrapePool) sync(targets []*Target) {
 				client:               sp.client,
 				timeout:              timeout,
 				bodySizeLimit:        bodySizeLimit,
-				acceptHeader:         acceptHeader(sp.config.ScrapeProtocols),
+				acceptHeader:         acceptHeader(sp.config.ScrapeProtocols, sp.config.AllowUTF8Names),
 				acceptEncodingHeader: acceptEncodingHeader(enableCompression),
 				metrics:              sp.metrics,
 			}
@@ -667,11 +667,16 @@ var errBodySizeLimit = errors.New("body size limit exceeded")
 // acceptHeader transforms preference from the options into specific header values as
 // https://www.rfc-editor.org/rfc/rfc9110.html#name-accept defines.
 // No validation is here, we expect scrape protocols to be validated already.
-func acceptHeader(sps []config.ScrapeProtocol) string {
+func acceptHeader(sps []config.ScrapeProtocol, allowUTF8Names bool) string {
 	var vals []string
 	weight := len(config.ScrapeProtocolsHeaders) + 1
 	for _, sp := range sps {
-		vals = append(vals, fmt.Sprintf("%s;q=0.%d", config.ScrapeProtocolsHeaders[sp], weight))
+		val := config.ScrapeProtocolsHeaders[sp]
+		if allowUTF8Names {
+			val += ";"+config.UTF8NamesHeader
+		}
+		val += fmt.Sprintf(";q=0.%d", weight)
+		vals = append(vals, val)
 		weight--
 	}
 	// Default match anything.

scrape/scrape_test.go

@@ -2336,12 +2336,15 @@ func TestTargetScraperScrapeOK(t *testing.T) {
 
 	server := httptest.NewServer(
 		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			if protobufParsing {
 			accept := r.Header.Get("Accept")
+			if protobufParsing {
 				if !strings.HasPrefix(accept, "application/vnd.google.protobuf;") {
 					t.Errorf("Expected Accept header to prefer application/vnd.google.protobuf, got %q", accept)
 				}
 			}
+			if strings.Contains(accept, "validchars=utf8") {
+				t.Errorf("Expected Accept header not to allow utf8, got %q", accept)
+			}
 
 			timeout := r.Header.Get("X-Prometheus-Scrape-Timeout-Seconds")
 			if timeout != expectedTimeout {
@@ -2381,9 +2384,68 @@ func TestTargetScraperScrapeOK(t *testing.T) {
 		require.Equal(t, "metric_a 1\nmetric_b 2\n", buf.String())
 	}
 
-	runTest(acceptHeader(config.DefaultScrapeProtocols))
+	runTest(acceptHeader(config.DefaultScrapeProtocols, false))
 	protobufParsing = true
-	runTest(acceptHeader(config.DefaultProtoFirstScrapeProtocols))
+	runTest(acceptHeader(config.DefaultProtoFirstScrapeProtocols, false))
+}
+
+func TestUTF8TargetScraperScrapeOK(t *testing.T) {
+	const (
+		configTimeout   = 1500 * time.Millisecond
+		expectedTimeout = "1.5"
+	)
+
+	server := httptest.NewServer(
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			accept := r.Header.Get("Accept")
+			if !strings.Contains(accept, "validchars=utf8") {
+				t.Errorf("Expected Accept header to allow utf8, got %q", accept)
+			}
+
+			timeout := r.Header.Get("X-Prometheus-Scrape-Timeout-Seconds")
+			if timeout != expectedTimeout {
+				t.Errorf("Expected scrape timeout header %q, got %q", expectedTimeout, timeout)
+			}
+
+			w.Header().Set("Content-Type", `text/plain; version=1.0.0; validchars=utf8`)
+			w.Write([]byte(`{"metric.a"} 1
+{"metric.b"} 2
+`))
+		}),
+	)
+	defer server.Close()
+
+	serverURL, err := url.Parse(server.URL)
+	if err != nil {
+		panic(err)
+	}
+
+	runTest := func(acceptHeader string) {
+		ts := &targetScraper{
+			Target: &Target{
+				labels: labels.FromStrings(
+					model.SchemeLabel, serverURL.Scheme,
+					model.AddressLabel, serverURL.Host,
+				),
+			},
+			client:       http.DefaultClient,
+			timeout:      configTimeout,
+			acceptHeader: acceptHeader,
+		}
+		var buf bytes.Buffer
+
+		resp, err := ts.scrape(context.Background())
+		require.NoError(t, err)
+		contentType, err := ts.readResponse(context.Background(), resp, &buf)
+		require.NoError(t, err)
+		require.Equal(t, "text/plain; version=1.0.0; validchars=utf8", contentType)
+		require.Equal(t, `{"metric.a"} 1
+{"metric.b"} 2
+`, buf.String())
+	}
+
+	runTest(acceptHeader(config.DefaultScrapeProtocols, true))
+	runTest(acceptHeader(config.DefaultProtoFirstScrapeProtocols, true))
 }
 
 func TestTargetScrapeScrapeCancel(t *testing.T) {
@@ -2409,7 +2471,7 @@ func TestTargetScrapeScrapeCancel(t *testing.T) {
 			),
 		},
 		client:       http.DefaultClient,
-		acceptHeader: acceptHeader(config.DefaultGlobalConfig.ScrapeProtocols),
+		acceptHeader: acceptHeader(config.DefaultGlobalConfig.ScrapeProtocols, false),
 	}
 	ctx, cancel := context.WithCancel(context.Background())
 
@@ -2464,7 +2526,7 @@ func TestTargetScrapeScrapeNotFound(t *testing.T) {
 			),
 		},
 		client:       http.DefaultClient,
-		acceptHeader: acceptHeader(config.DefaultGlobalConfig.ScrapeProtocols),
+		acceptHeader: acceptHeader(config.DefaultGlobalConfig.ScrapeProtocols, false),
 	}
 
 	resp, err := ts.scrape(context.Background())
@@ -2508,7 +2570,7 @@ func TestTargetScraperBodySizeLimit(t *testing.T) {
 		},
 		client:        http.DefaultClient,
 		bodySizeLimit: bodySizeLimit,
-		acceptHeader:  acceptHeader(config.DefaultGlobalConfig.ScrapeProtocols),
+		acceptHeader:  acceptHeader(config.DefaultGlobalConfig.ScrapeProtocols, false),
 		metrics:       newTestScrapeMetrics(t),
 	}
 	var buf bytes.Buffer

storage/remote/client.go

@@ -274,6 +274,7 @@ func (c *Client) Read(ctx context.Context, query *prompb.Query) (*prompb.QueryRe
 	c.readQueries.Inc()
 	defer c.readQueries.Dec()
 
+	// XXXXXX based on content negotiation we may need to escape the query. (If the other side is old)
 	req := &prompb.ReadRequest{
 		// TODO: Support batching multiple queries into one read request,
 		// as the protobuf interface allows for it.

util/fmtutil/format.go

@@ -58,6 +58,10 @@ func MetricTextToWriteRequest(input io.Reader, labels map[string]string) (*promp
 func MetricFamiliesToWriteRequest(mf map[string]*dto.MetricFamily, extraLabels map[string]string) (*prompb.WriteRequest, error) {
 	wr := &prompb.WriteRequest{}
 
+	if model.NameValidationScheme == model.UTF8Validation {
+		wr.Utf8Names = true
+	}
+
 	// build metric list
 	sortedMetricNames := make([]string, 0, len(mf))
 	for metric := range mf {