Merge branch 'release-3.0' into fix-migration-guide

Signed-off-by: Fiona Liao <fiona.liao@grafana.com>
2024-11-12 09:43:42 +00:00 · 2024-11-12 09:43:42 +00:00 · 928e691bc6
parent 67764d7cfd 14f7a8e6ba
commit 928e691bc6
30 changed files with 461 additions and 163 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -2,7 +2,13 @@

 ## unreleased

+## 3.0.0-rc.1 / 2024-11-11
+
+* [CHANGE] Set the `GOMAXPROCS` variable automatically to match the Linux CPU quota. Use `--no-auto-gomaxprocs` to disable it. The `auto-gomaxprocs` feature flag was removed. #15376
+* [CHANGE] Set the `GOMEMLIMIT` variable automatically to match the Linux container memory limit. Use `--no-auto-gomemlimit` to disable it. The `auto-gomemlimit` feature flag was removed. #15373
+* [FEATURE] OTLP receiver: Ability to skip UTF-8 normalization using `otlp.translation_strategy = NoUTF8EscapingWithSuffixes` configuration option. #15384
 * [BUGFIX] Scraping: Don't log errors on empty scrapes. #15357
+* [BUGFIX] UI: fix selector / series formatting for empty metric names. #15341

 ## 3.0.0-rc.0 / 2024-10-31

--- a/2
+++ b/2
@ -1 +1 @@
-3.0.0-rc.0
+3.0.0-rc.1
--- a/cmd/prometheus/main.go
+++ b/cmd/prometheus/main.go
@ -196,13 +196,14 @@ type flagConfig struct {
 	enableAutoReload   bool
 	autoReloadInterval model.Duration

-	featureList   []string
-	memlimitRatio float64
+	maxprocsEnable bool
+	memlimitEnable bool
+	memlimitRatio  float64
+
+	featureList []string
 	// These options are extracted from featureList
 	// for ease of use.
 	enablePerStepStats       bool
-	enableAutoGOMAXPROCS     bool
-	enableAutoGOMEMLIMIT     bool
 	enableConcurrentRuleEval bool

 	prometheusURL   string
@ -234,18 +235,12 @@ func (c *flagConfig) setFeatureListOptions(logger *slog.Logger) error {
 			case "promql-per-step-stats":
 				c.enablePerStepStats = true
 				logger.Info("Experimental per-step statistics reporting")
-			case "auto-gomaxprocs":
-				c.enableAutoGOMAXPROCS = true
-				logger.Info("Automatically set GOMAXPROCS to match Linux container CPU quota")
 			case "auto-reload-config":
 				c.enableAutoReload = true
 				if s := time.Duration(c.autoReloadInterval).Seconds(); s > 0 && s < 1 {
 					c.autoReloadInterval, _ = model.ParseDuration("1s")
 				}
 				logger.Info("Enabled automatic configuration file reloading. Checking for configuration changes every", "interval", c.autoReloadInterval)
-			case "auto-gomemlimit":
-				c.enableAutoGOMEMLIMIT = true
-				logger.Info("Automatically set GOMEMLIMIT to match Linux container or system memory limit")
 			case "concurrent-rule-eval":
 				c.enableConcurrentRuleEval = true
 				logger.Info("Experimental concurrent rule evaluation enabled.")
@ -332,6 +327,10 @@ func main() {
 	a.Flag("web.listen-address", "Address to listen on for UI, API, and telemetry. Can be repeated.").
 		Default("0.0.0.0:9090").StringsVar(&cfg.web.ListenAddresses)

+	a.Flag("auto-gomaxprocs", "Automatically set GOMAXPROCS to match Linux container CPU quota").
+		Default("true").BoolVar(&cfg.maxprocsEnable)
+	a.Flag("auto-gomemlimit", "Automatically set GOMEMLIMIT to match Linux container or system memory limit").
+		Default("true").BoolVar(&cfg.memlimitEnable)
 	a.Flag("auto-gomemlimit.ratio", "The ratio of reserved GOMEMLIMIT memory to the detected maximum container or system memory").
 		Default("0.9").FloatVar(&cfg.memlimitRatio)

@ -515,7 +514,7 @@ 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: auto-gomemlimit, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, auto-gomaxprocs, native-histograms, created-timestamp-zero-ingestion, concurrent-rule-eval, delayed-compaction, old-ui. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details.").
+	a.Flag("enable-feature", "Comma separated feature names to enable. Valid options: exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, auto-gomaxprocs, native-histograms, created-timestamp-zero-ingestion, concurrent-rule-eval, delayed-compaction, old-ui. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details.").
 		Default("").StringsVar(&cfg.featureList)

 	a.Flag("agent", "Run Prometheus in 'Agent mode'.").BoolVar(&agentMode)
@ -766,7 +765,7 @@ func main() {
 		ruleManager *rules.Manager
 	)

-	if cfg.enableAutoGOMAXPROCS {
+	if cfg.maxprocsEnable {
 		l := func(format string, a ...interface{}) {
 			logger.Info(fmt.Sprintf(strings.TrimPrefix(format, "maxprocs: "), a...), "component", "automaxprocs")
 		}
@ -775,7 +774,7 @@ func main() {
 		}
 	}

-	if cfg.enableAutoGOMEMLIMIT {
+	if cfg.memlimitEnable {
 		if _, err := memlimit.SetGoMemLimitWithOpts(
 			memlimit.WithRatio(cfg.memlimitRatio),
 			memlimit.WithProvider(
--- a/config/config.go
+++ b/config/config.go
@ -106,6 +106,18 @@ func Load(s string, logger *slog.Logger) (*Config, error) {
 	if !b.Labels().IsEmpty() {
 		cfg.GlobalConfig.ExternalLabels = b.Labels()
 	}
+
+	switch cfg.OTLPConfig.TranslationStrategy {
+	case UnderscoreEscapingWithSuffixes:
+	case "":
+	case NoUTF8EscapingWithSuffixes:
+		if cfg.GlobalConfig.MetricNameValidationScheme == LegacyValidationConfig {
+			return nil, errors.New("OTLP translation strategy NoUTF8EscapingWithSuffixes is not allowed when UTF8 is disabled")
+		}
+	default:
+		return nil, fmt.Errorf("unsupported OTLP translation strategy %q", cfg.OTLPConfig.TranslationStrategy)
+	}
+
 	return cfg, nil
 }

@ -239,7 +251,9 @@ var (
 	}

 	// DefaultOTLPConfig is the default OTLP configuration.
-	DefaultOTLPConfig = OTLPConfig{}
+	DefaultOTLPConfig = OTLPConfig{
+		TranslationStrategy: UnderscoreEscapingWithSuffixes,
+	}
 )

 // Config is the top-level configuration for Prometheus's config files.
@ -1402,9 +1416,20 @@ func getGoGCEnv() int {
 	return DefaultRuntimeConfig.GoGC
 }

+type translationStrategyOption string
+
+var (
+	// NoUTF8EscapingWithSuffixes will keep UTF-8 characters as they are, units and type suffixes will still be added.
+	NoUTF8EscapingWithSuffixes translationStrategyOption = "NoUTF8EscapingWithSuffixes"
+	// UnderscoreEscapingWithSuffixes is the default option for translating OTLP to Prometheus.
+	// This option will translate all UTF-8 characters to underscores, while adding units and type suffixes.
+	UnderscoreEscapingWithSuffixes translationStrategyOption = "UnderscoreEscapingWithSuffixes"
+)
+
 // OTLPConfig is the configuration for writing to the OTLP endpoint.
 type OTLPConfig struct {
-	PromoteResourceAttributes []string `yaml:"promote_resource_attributes,omitempty"`
+	PromoteResourceAttributes []string                  `yaml:"promote_resource_attributes,omitempty"`
+	TranslationStrategy       translationStrategyOption `yaml:"translation_strategy,omitempty"`
 }

 // UnmarshalYAML implements the yaml.Unmarshaler interface.
--- a/config/config_test.go
+++ b/config/config_test.go
@ -168,6 +168,7 @@ var expectedConf = &Config{
 		PromoteResourceAttributes: []string{
 			"k8s.cluster.name", "k8s.job.name", "k8s.namespace.name",
 		},
+		TranslationStrategy: UnderscoreEscapingWithSuffixes,
 	},

 	RemoteReadConfigs: []*RemoteReadConfig{
@ -1553,6 +1554,67 @@ func TestOTLPSanitizeResourceAttributes(t *testing.T) {
 	})
 }

+func TestOTLPAllowUTF8(t *testing.T) {
+	t.Run("good config", func(t *testing.T) {
+		fpath := filepath.Join("testdata", "otlp_allow_utf8.good.yml")
+		verify := func(t *testing.T, conf *Config, err error) {
+			t.Helper()
+			require.NoError(t, err)
+			require.Equal(t, NoUTF8EscapingWithSuffixes, conf.OTLPConfig.TranslationStrategy)
+		}
+
+		t.Run("LoadFile", func(t *testing.T) {
+			conf, err := LoadFile(fpath, false, promslog.NewNopLogger())
+			verify(t, conf, err)
+		})
+		t.Run("Load", func(t *testing.T) {
+			content, err := os.ReadFile(fpath)
+			require.NoError(t, err)
+			conf, err := Load(string(content), promslog.NewNopLogger())
+			verify(t, conf, err)
+		})
+	})
+
+	t.Run("incompatible config", func(t *testing.T) {
+		fpath := filepath.Join("testdata", "otlp_allow_utf8.incompatible.yml")
+		verify := func(t *testing.T, err error) {
+			t.Helper()
+			require.ErrorContains(t, err, `OTLP translation strategy NoUTF8EscapingWithSuffixes is not allowed when UTF8 is disabled`)
+		}
+
+		t.Run("LoadFile", func(t *testing.T) {
+			_, err := LoadFile(fpath, false, promslog.NewNopLogger())
+			verify(t, err)
+		})
+		t.Run("Load", func(t *testing.T) {
+			content, err := os.ReadFile(fpath)
+			require.NoError(t, err)
+			_, err = Load(string(content), promslog.NewNopLogger())
+			t.Log("err", err)
+			verify(t, err)
+		})
+	})
+
+	t.Run("bad config", func(t *testing.T) {
+		fpath := filepath.Join("testdata", "otlp_allow_utf8.bad.yml")
+		verify := func(t *testing.T, err error) {
+			t.Helper()
+			require.ErrorContains(t, err, `unsupported OTLP translation strategy "Invalid"`)
+		}
+
+		t.Run("LoadFile", func(t *testing.T) {
+			_, err := LoadFile(fpath, false, promslog.NewNopLogger())
+			verify(t, err)
+		})
+		t.Run("Load", func(t *testing.T) {
+			content, err := os.ReadFile(fpath)
+			require.NoError(t, err)
+			_, err = Load(string(content), promslog.NewNopLogger())
+			verify(t, err)
+		})
+	})
+}
+
 func TestLoadConfig(t *testing.T) {
 	// Parse a valid file that sets a global scrape timeout. This tests whether parsing
 	// an overwritten default field in the global config permanently changes the default.
--- a/config/testdata/otlp_allow_utf8.bad.yml
+++ b/config/testdata/otlp_allow_utf8.bad.yml
@ -0,0 +1,4 @@
+global:
+  metric_name_validation_scheme: legacy
+otlp:
+  translation_strategy: Invalid
--- a/config/testdata/otlp_allow_utf8.good.yml
+++ b/config/testdata/otlp_allow_utf8.good.yml
@ -0,0 +1,2 @@
+otlp:
+  translation_strategy: NoUTF8EscapingWithSuffixes
--- a/config/testdata/otlp_allow_utf8.incompatible.yml
+++ b/config/testdata/otlp_allow_utf8.incompatible.yml
@ -0,0 +1,4 @@
+global:
+  metric_name_validation_scheme: legacy
+otlp:
+  translation_strategy: NoUTF8EscapingWithSuffixes
--- a/docs/command-line/prometheus.md
+++ b/docs/command-line/prometheus.md
@ -17,6 +17,8 @@ The Prometheus monitoring server
 | <code class="text-nowrap">--config.file</code> | Prometheus configuration file path. | `prometheus.yml` |
 | <code class="text-nowrap">--config.auto-reload-interval</code> | Specifies the interval for checking and automatically reloading the Prometheus configuration file upon detecting changes. | `30s` |
 | <code class="text-nowrap">--web.listen-address</code> <code class="text-nowrap">...<code class="text-nowrap"> | Address to listen on for UI, API, and telemetry. Can be repeated. | `0.0.0.0:9090` |
+| <code class="text-nowrap">--auto-gomaxprocs</code> | Automatically set GOMAXPROCS to match Linux container CPU quota | `true` |
+| <code class="text-nowrap">--auto-gomemlimit</code> | Automatically set GOMEMLIMIT to match Linux container or system memory limit | `true` |
 | <code class="text-nowrap">--auto-gomemlimit.ratio</code> | The ratio of reserved GOMEMLIMIT memory to the detected maximum container or system memory | `0.9` |
 | <code class="text-nowrap">--web.config.file</code> | [EXPERIMENTAL] Path to configuration file that can enable TLS or authentication. |  |
 | <code class="text-nowrap">--web.read-timeout</code> | Maximum duration before timing out read of the request, and closing idle connections. | `5m` |
@ -58,7 +60,7 @@ The Prometheus monitoring server
 | <code class="text-nowrap">--query.timeout</code> | Maximum time a query may take before being aborted. Use with server mode only. | `2m` |
 | <code class="text-nowrap">--query.max-concurrency</code> | Maximum number of queries executed concurrently. Use with server mode only. | `20` |
 | <code class="text-nowrap">--query.max-samples</code> | Maximum number of samples a single query can load into memory. Note that queries will fail if they try to load more samples than this into memory, so this also limits the number of samples a query can return. Use with server mode only. | `50000000` |
-| <code class="text-nowrap">--enable-feature</code> <code class="text-nowrap">...<code class="text-nowrap"> | Comma separated feature names to enable. Valid options: auto-gomemlimit, exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, auto-gomaxprocs, native-histograms, created-timestamp-zero-ingestion, concurrent-rule-eval, delayed-compaction, old-ui. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details. |  |
+| <code class="text-nowrap">--enable-feature</code> <code class="text-nowrap">...<code class="text-nowrap"> | Comma separated feature names to enable. Valid options: exemplar-storage, expand-external-labels, memory-snapshot-on-shutdown, promql-per-step-stats, promql-experimental-functions, extra-scrape-metrics, auto-gomaxprocs, native-histograms, created-timestamp-zero-ingestion, concurrent-rule-eval, delayed-compaction, old-ui. See https://prometheus.io/docs/prometheus/latest/feature_flags/ for more details. |  |
 | <code class="text-nowrap">--agent</code> | Run Prometheus in 'Agent mode'. |  |
 | <code class="text-nowrap">--log.level</code> | Only log messages with the given severity or above. One of: [debug, info, warn, error] | `info` |
 | <code class="text-nowrap">--log.format</code> | Output format of log messages. One of: [logfmt, json] | `logfmt` |
--- a/docs/configuration/configuration.md
+++ b/docs/configuration/configuration.md
@ -171,8 +171,17 @@ remote_write:
  [ - <remote_write> ... ]

 # Settings related to the OTLP receiver feature.
+# See https://prometheus.io/docs/guides/opentelemetry/ for best practices.
 otlp:
  [ promote_resource_attributes: [<string>, ...] | default = [ ] ]
+  # Configures translation of OTLP metrics when received through the OTLP metrics
+  # endpoint. Available values:
+  # - "UnderscoreEscapingWithSuffixes" refers to commonly agreed normalization used
+  #   by OpenTelemetry in https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/pkg/translator/prometheus
+  # - "NoUTF8EscapingWithSuffixes" is a mode that relies on UTF-8 support in Prometheus.
+  #   It preserves all special characters like dots, but it still add required suffixes
+  #   for units and _total like in UnderscoreEscapingWithSuffixes.
+  [ translation_strategy: <string> | default = "UnderscoreEscapingWithSuffixes" ]

 # Settings related to the remote read feature.
 remote_read:
--- a/docs/feature_flags.md
+++ b/docs/feature_flags.md
@ -47,20 +47,6 @@ statistics. Currently this is limited to totalQueryableSamples.
 When disabled in either the engine or the query, per-step statistics are not
 computed at all.

-## Auto GOMAXPROCS
-
-`--enable-feature=auto-gomaxprocs`
-
-When enabled, GOMAXPROCS variable is automatically set to match Linux container CPU quota.
-
-## Auto GOMEMLIMIT
-
-`--enable-feature=auto-gomemlimit`
-
-When enabled, the GOMEMLIMIT variable is automatically set to match the Linux container memory limit. If there is no container limit, or the process is running outside of containers, the system memory total is used.
-
-There is also an additional tuning flag, `--auto-gomemlimit.ratio`, which allows controlling how much of the memory is used for Prometheus. The remainder is reserved for memory outside the process. For example, kernel page cache. Page cache is important for Prometheus TSDB query performance. The default is `0.9`, which means 90% of the memory limit will be used for Prometheus.
-
 ## Native Histograms

 `--enable-feature=native-histograms`
--- a/docs/migration.md
+++ b/docs/migration.md
@ -31,6 +31,14 @@ This document offers guidance on migrating from Prometheus 2.x to Prometheus 3.0
      `http://example.com/metrics:80` respectively, add them to your target URLs
  - `agent`
      - Instead use the dedicated `--agent` CLI flag.
+  - `auto-gomemlimit`
+      - Prometheus v3 will automatically set `GOMEMLIMIT` to match the Linux 
+      container memory limit. If there is no container limit, or the process is 
+      running outside of containers, the system memory total is used. To disable 
+      this, `--no-auto-gomemlimit` is available.
+  - `auto-gomaxprocs`
+      - Prometheus v3 will automatically set `GOMAXPROCS` to match the Linux 
+      container CPU quota. To disable this, `--no-auto-gomaxprocs` is available.

  Prometheus v3 will log a warning if you continue to pass these to 
  `--enable-feature`.
@ -100,19 +108,25 @@ may now fail if this fallback protocol is not specified.
 ## Miscellaneous

 ### TSDB format and downgrade
-The TSDB format has been changed in Prometheus v2.55 in preparation for changes 
+
+The TSDB format has been changed slightly in Prometheus v2.55 in preparation for changes 
 to the index format. Consequently, a Prometheus v3 TSDB can only be read by a
-Prometheus v2.55 or newer.
-Before upgrading to Prometheus v3 please upgrade to v2.55 first and confirm 
-Prometheus works as expected. Only then continue with the upgrade to v3.
+Prometheus v2.55 or newer. Keep that in mind when upgrading to v3 -- you will be only
+able to downgrade to v2.55, not lower, without loosing your TSDB persitent data.
+
+As an extra safety measure, you could optionally consider upgrading to v2.55 first and
+confirm Prometheus works as expected, before upgrading to v3.

 ### TSDB storage contract
+
 TSDB compatible storage is now expected to return results matching the specified 
 selectors. This might impact some third party implementations, most likely 
 implementing `remote_read`.
+
 This contract is not explicitly enforced, but can cause undefined behavior.

 ### UTF-8 names
+
 Prometheus v3 supports UTF-8 in metric and label names. This means metric and
 label names can change after upgrading according to what is exposed by
 endpoints. Furthermore, metric and label names that would have previously been
--- a/documentation/examples/prometheus-otlp.yml
+++ b/documentation/examples/prometheus-otlp.yml
@ -0,0 +1,31 @@
+# my global config
+global:
+  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
+
+otlp:
+  # Recommended attributes to be promoted to labels.
+  promote_resource_attributes:
+    - service.instance.id
+    - service.name
+    - service.namespace
+    - cloud.availability_zone
+    - cloud.region
+    - container.name
+    - deployment.environment.name
+    - k8s.cluster.name
+    - k8s.container.name
+    - k8s.cronjob.name
+    - k8s.daemonset.name
+    - k8s.deployment.name
+    - k8s.job.name
+    - k8s.namespace.name
+    - k8s.pod.name
+    - k8s.replicaset.name
+    - k8s.statefulset.name
+  # Ingest OTLP data keeping UTF-8 characters in metric/label names.
+  translation_strategy: NoUTF8EscapingWithSuffixes
+
+storage:
+  # OTLP is a push-based protocol, Out of order samples is a common scenario.
+  tsdb:
+    out_of_order_time_window: 30m
--- a/storage/remote/otlptranslator/prometheus/helpers_from_stdlib.go
+++ b/storage/remote/otlptranslator/prometheus/helpers_from_stdlib.go
@ -0,0 +1,106 @@
+// Copyright 2024 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// Provenance-includes-location: https://github.com/golang/go/blob/f2d118fd5f7e872804a5825ce29797f81a28b0fa/src/strings/strings.go
+// Provenance-includes-license: BSD-3-Clause
+// Provenance-includes-copyright: Copyright The Go Authors.
+
+package prometheus
+
+import "strings"
+
+// fieldsFunc is a copy of strings.FieldsFunc from the Go standard library,
+// but it also returns the separators as part of the result.
+func fieldsFunc(s string, f func(rune) bool) ([]string, []string) {
+	// A span is used to record a slice of s of the form s[start:end].
+	// The start index is inclusive and the end index is exclusive.
+	type span struct {
+		start int
+		end   int
+	}
+	spans := make([]span, 0, 32)
+	separators := make([]string, 0, 32)
+
+	// Find the field start and end indices.
+	// Doing this in a separate pass (rather than slicing the string s
+	// and collecting the result substrings right away) is significantly
+	// more efficient, possibly due to cache effects.
+	start := -1 // valid span start if >= 0
+	for end, rune := range s {
+		if f(rune) {
+			if start >= 0 {
+				spans = append(spans, span{start, end})
+				// Set start to a negative value.
+				// Note: using -1 here consistently and reproducibly
+				// slows down this code by a several percent on amd64.
+				start = ^start
+				separators = append(separators, string(s[end]))
+			}
+		} else {
+			if start < 0 {
+				start = end
+			}
+		}
+	}
+
+	// Last field might end at EOF.
+	if start >= 0 {
+		spans = append(spans, span{start, len(s)})
+	}
+
+	// Create strings from recorded field indices.
+	a := make([]string, len(spans))
+	for i, span := range spans {
+		a[i] = s[span.start:span.end]
+	}
+
+	return a, separators
+}
+
+// join is a copy of strings.Join from the Go standard library,
+// but it also accepts a slice of separators to join the elements with.
+// If the slice of separators is shorter than the slice of elements, use a default value.
+// We also don't check for integer overflow.
+func join(elems []string, separators []string, def string) string {
+	switch len(elems) {
+	case 0:
+		return ""
+	case 1:
+		return elems[0]
+	}
+
+	var n int
+	var sep string
+	sepLen := len(separators)
+	for i, elem := range elems {
+		if i >= sepLen {
+			sep = def
+		} else {
+			sep = separators[i]
+		}
+		n += len(sep) + len(elem)
+	}
+
+	var b strings.Builder
+	b.Grow(n)
+	b.WriteString(elems[0])
+	for i, s := range elems[1:] {
+		if i >= sepLen {
+			sep = def
+		} else {
+			sep = separators[i]
+		}
+		b.WriteString(sep)
+		b.WriteString(s)
+	}
+	return b.String()
+}
--- a/storage/remote/otlptranslator/prometheus/normalize_label.go
+++ b/storage/remote/otlptranslator/prometheus/normalize_label.go
@ -29,9 +29,9 @@ import (
 //
 // Labels that start with non-letter rune will be prefixed with "key_".
 // An exception is made for double-underscores which are allowed.
-func NormalizeLabel(label string) string {
+func NormalizeLabel(label string, allowUTF8 bool) string {
 	// Trivial case
-	if len(label) == 0 {
+	if len(label) == 0 || allowUTF8 {
 		return label
 	}

--- a/storage/remote/otlptranslator/prometheus/normalize_label_test.go
+++ b/storage/remote/otlptranslator/prometheus/normalize_label_test.go
@ -22,24 +22,27 @@ import (

 func TestNormalizeLabel(t *testing.T) {
 	tests := []struct {
-		label    string
-		expected string
+		label        string
+		expected     string
+		expectedUTF8 string
 	}{
-		{"", ""},
-		{"label:with:colons", "label_with_colons"}, // Without UTF-8 support, colons are only allowed in metric names
-		{"LabelWithCapitalLetters", "LabelWithCapitalLetters"},
-		{"label!with&special$chars)", "label_with_special_chars_"},
-		{"label_with_foreign_characters_字符", "label_with_foreign_characters___"},
-		{"label.with.dots", "label_with_dots"},
-		{"123label", "key_123label"},
-		{"_label_starting_with_underscore", "key_label_starting_with_underscore"},
-		{"__label_starting_with_2underscores", "__label_starting_with_2underscores"},
+		{"", "", ""},
+		{"label:with:colons", "label_with_colons", "label:with:colons"}, // Without UTF-8 support, colons are only allowed in metric names
+		{"LabelWithCapitalLetters", "LabelWithCapitalLetters", "LabelWithCapitalLetters"},
+		{"label!with&special$chars)", "label_with_special_chars_", "label!with&special$chars)"},
+		{"label_with_foreign_characters_字符", "label_with_foreign_characters___", "label_with_foreign_characters_字符"},
+		{"label.with.dots", "label_with_dots", "label.with.dots"},
+		{"123label", "key_123label", "123label"},
+		{"_label_starting_with_underscore", "key_label_starting_with_underscore", "_label_starting_with_underscore"},
+		{"__label_starting_with_2underscores", "__label_starting_with_2underscores", "__label_starting_with_2underscores"},
 	}

 	for i, test := range tests {
 		t.Run(fmt.Sprintf("test_%d", i), func(t *testing.T) {
-			result := NormalizeLabel(test.label)
+			result := NormalizeLabel(test.label, false)
 			require.Equal(t, test.expected, result)
+			uTF8result := NormalizeLabel(test.label, true)
+			require.Equal(t, test.expectedUTF8, uTF8result)
 		})
 	}
 }
--- a/storage/remote/otlptranslator/prometheus/normalize_name.go
+++ b/storage/remote/otlptranslator/prometheus/normalize_name.go
@ -88,27 +88,32 @@ var perUnitMap = map[string]string{
 // See rules at https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels,
 // https://prometheus.io/docs/practices/naming/#metric-and-label-naming
 // and https://github.com/open-telemetry/opentelemetry-specification/blob/v1.38.0/specification/compatibility/prometheus_and_openmetrics.md#otlp-metric-points-to-prometheus.
-func BuildCompliantName(metric pmetric.Metric, namespace string, addMetricSuffixes bool) string {
+func BuildCompliantName(metric pmetric.Metric, namespace string, addMetricSuffixes, allowUTF8 bool) string {
 	// Full normalization following standard Prometheus naming conventions
 	if addMetricSuffixes {
-		return normalizeName(metric, namespace)
+		return normalizeName(metric, namespace, allowUTF8)
 	}

-	// Regexp for metric name characters that should be replaced with _.
-	invalidMetricCharRE := regexp.MustCompile(`[^a-zA-Z0-9:_]`)
+	var metricName string
+	if !allowUTF8 {
+		// Regexp for metric name characters that should be replaced with _.
+		invalidMetricCharRE := regexp.MustCompile(`[^a-zA-Z0-9:_]`)

-	// Simple case (no full normalization, no units, etc.).
-	metricName := strings.Join(strings.FieldsFunc(metric.Name(), func(r rune) bool {
-		return invalidMetricCharRE.MatchString(string(r))
-	}), "_")
+		// Simple case (no full normalization, no units, etc.).
+		metricName = strings.Join(strings.FieldsFunc(metric.Name(), func(r rune) bool {
+			return invalidMetricCharRE.MatchString(string(r))
+		}), "_")
+	} else {
+		metricName = metric.Name()
+	}

 	// Namespace?
 	if namespace != "" {
 		return namespace + "_" + metricName
 	}

-	// Metric name starts with a digit? Prefix it with an underscore.
-	if metricName != "" && unicode.IsDigit(rune(metricName[0])) {
+	// Metric name starts with a digit and utf8 not allowed? Prefix it with an underscore.
+	if metricName != "" && unicode.IsDigit(rune(metricName[0])) && !allowUTF8 {
 		metricName = "_" + metricName
 	}

@ -116,17 +121,18 @@ func BuildCompliantName(metric pmetric.Metric, namespace string, addMetricSuffix
 }

 // Build a normalized name for the specified metric.
-func normalizeName(metric pmetric.Metric, namespace string) string {
-	// Regexp for characters that can't be in a metric name token.
-	nonTokenMetricCharRE := regexp.MustCompile(`[^a-zA-Z0-9:]`)
-
+func normalizeName(metric pmetric.Metric, namespace string, allowUTF8 bool) string {
+	var translationFunc func(rune) bool
+	if !allowUTF8 {
+		nonTokenMetricCharRE := regexp.MustCompile(`[^a-zA-Z0-9:]`)
+		translationFunc = func(r rune) bool { return nonTokenMetricCharRE.MatchString(string(r)) }
+	} else {
+		translationFunc = func(r rune) bool { return !unicode.IsLetter(r) && !unicode.IsDigit(r) && r != ':' }
+	}
 	// Split metric name into "tokens" (of supported metric name runes).
 	// Note that this has the side effect of replacing multiple consecutive underscores with a single underscore.
 	// This is part of the OTel to Prometheus specification: https://github.com/open-telemetry/opentelemetry-specification/blob/v1.38.0/specification/compatibility/prometheus_and_openmetrics.md#otlp-metric-points-to-prometheus.
-	nameTokens := strings.FieldsFunc(
-		metric.Name(),
-		func(r rune) bool { return nonTokenMetricCharRE.MatchString(string(r)) },
-	)
+	nameTokens, separators := fieldsFunc(metric.Name(), translationFunc)

 	// Split unit at the '/' if any
 	unitTokens := strings.SplitN(metric.Unit(), "/", 2)
@ -137,7 +143,10 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 		var mainUnitProm, perUnitProm string
 		mainUnitOTel := strings.TrimSpace(unitTokens[0])
 		if mainUnitOTel != "" && !strings.ContainsAny(mainUnitOTel, "{}") {
-			mainUnitProm = cleanUpUnit(unitMapGetOrDefault(mainUnitOTel))
+			mainUnitProm = unitMapGetOrDefault(mainUnitOTel)
+			if !allowUTF8 {
+				mainUnitProm = cleanUpUnit(mainUnitProm)
+			}
 			if slices.Contains(nameTokens, mainUnitProm) {
 				mainUnitProm = ""
 			}
@ -148,7 +157,10 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 		if len(unitTokens) > 1 && unitTokens[1] != "" {
 			perUnitOTel := strings.TrimSpace(unitTokens[1])
 			if perUnitOTel != "" && !strings.ContainsAny(perUnitOTel, "{}") {
-				perUnitProm = cleanUpUnit(perUnitMapGetOrDefault(perUnitOTel))
+				perUnitProm = perUnitMapGetOrDefault(perUnitOTel)
+				if !allowUTF8 {
+					perUnitProm = cleanUpUnit(perUnitProm)
+				}
 			}
 			if perUnitProm != "" {
 				perUnitProm = "per_" + perUnitProm
@ -189,8 +201,12 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 		nameTokens = append([]string{namespace}, nameTokens...)
 	}

-	// Build the string from the tokens, separated with underscores
-	normalizedName := strings.Join(nameTokens, "_")
+	// Build the string from the tokens + separators.
+	// If UTF-8 isn't allowed, we'll use underscores as separators.
+	if !allowUTF8 {
+		separators = []string{}
+	}
+	normalizedName := join(nameTokens, separators, "_")

 	// Metric name cannot start with a digit, so prefix it with "_" in this case
 	if normalizedName != "" && unicode.IsDigit(rune(normalizedName[0])) {
--- a/storage/remote/otlptranslator/prometheus/normalize_name_test.go
+++ b/storage/remote/otlptranslator/prometheus/normalize_name_test.go
@ -25,92 +25,119 @@ import (
 )

 func TestByte(t *testing.T) {
-	require.Equal(t, "system_filesystem_usage_bytes", normalizeName(createGauge("system.filesystem.usage", "By"), ""))
+	require.Equal(t, "system_filesystem_usage_bytes", normalizeName(createGauge("system.filesystem.usage", "By"), "", false))
 }

 func TestByteCounter(t *testing.T) {
-	require.Equal(t, "system_io_bytes_total", normalizeName(createCounter("system.io", "By"), ""))
-	require.Equal(t, "network_transmitted_bytes_total", normalizeName(createCounter("network_transmitted_bytes_total", "By"), ""))
+	require.Equal(t, "system_io_bytes_total", normalizeName(createCounter("system.io", "By"), "", false))
+	require.Equal(t, "network_transmitted_bytes_total", normalizeName(createCounter("network_transmitted_bytes_total", "By"), "", false))
 }

 func TestWhiteSpaces(t *testing.T) {
-	require.Equal(t, "system_filesystem_usage_bytes", normalizeName(createGauge("\t system.filesystem.usage       ", "  By\t"), ""))
+	require.Equal(t, "system_filesystem_usage_bytes", normalizeName(createGauge("\t system.filesystem.usage       ", "  By\t"), "", false))
 }

 func TestNonStandardUnit(t *testing.T) {
-	require.Equal(t, "system_network_dropped", normalizeName(createGauge("system.network.dropped", "{packets}"), ""))
+	require.Equal(t, "system_network_dropped", normalizeName(createGauge("system.network.dropped", "{packets}"), "", false))
 }

 func TestNonStandardUnitCounter(t *testing.T) {
-	require.Equal(t, "system_network_dropped_total", normalizeName(createCounter("system.network.dropped", "{packets}"), ""))
+	require.Equal(t, "system_network_dropped_total", normalizeName(createCounter("system.network.dropped", "{packets}"), "", false))
 }

 func TestBrokenUnit(t *testing.T) {
-	require.Equal(t, "system_network_dropped_packets", normalizeName(createGauge("system.network.dropped", "packets"), ""))
-	require.Equal(t, "system_network_packets_dropped", normalizeName(createGauge("system.network.packets.dropped", "packets"), ""))
-	require.Equal(t, "system_network_packets", normalizeName(createGauge("system.network.packets", "packets"), ""))
+	require.Equal(t, "system_network_dropped_packets", normalizeName(createGauge("system.network.dropped", "packets"), "", false))
+	require.Equal(t, "system_network_packets_dropped", normalizeName(createGauge("system.network.packets.dropped", "packets"), "", false))
+	require.Equal(t, "system_network_packets", normalizeName(createGauge("system.network.packets", "packets"), "", false))
 }

 func TestBrokenUnitCounter(t *testing.T) {
-	require.Equal(t, "system_network_dropped_packets_total", normalizeName(createCounter("system.network.dropped", "packets"), ""))
-	require.Equal(t, "system_network_packets_dropped_total", normalizeName(createCounter("system.network.packets.dropped", "packets"), ""))
-	require.Equal(t, "system_network_packets_total", normalizeName(createCounter("system.network.packets", "packets"), ""))
+	require.Equal(t, "system_network_dropped_packets_total", normalizeName(createCounter("system.network.dropped", "packets"), "", false))
+	require.Equal(t, "system_network_packets_dropped_total", normalizeName(createCounter("system.network.packets.dropped", "packets"), "", false))
+	require.Equal(t, "system_network_packets_total", normalizeName(createCounter("system.network.packets", "packets"), "", false))
 }

 func TestRatio(t *testing.T) {
-	require.Equal(t, "hw_gpu_memory_utilization_ratio", normalizeName(createGauge("hw.gpu.memory.utilization", "1"), ""))
-	require.Equal(t, "hw_fan_speed_ratio", normalizeName(createGauge("hw.fan.speed_ratio", "1"), ""))
-	require.Equal(t, "objects_total", normalizeName(createCounter("objects", "1"), ""))
+	require.Equal(t, "hw_gpu_memory_utilization_ratio", normalizeName(createGauge("hw.gpu.memory.utilization", "1"), "", false))
+	require.Equal(t, "hw_fan_speed_ratio", normalizeName(createGauge("hw.fan.speed_ratio", "1"), "", false))
+	require.Equal(t, "objects_total", normalizeName(createCounter("objects", "1"), "", false))
 }

 func TestHertz(t *testing.T) {
-	require.Equal(t, "hw_cpu_speed_limit_hertz", normalizeName(createGauge("hw.cpu.speed_limit", "Hz"), ""))
+	require.Equal(t, "hw_cpu_speed_limit_hertz", normalizeName(createGauge("hw.cpu.speed_limit", "Hz"), "", false))
 }

 func TestPer(t *testing.T) {
-	require.Equal(t, "broken_metric_speed_km_per_hour", normalizeName(createGauge("broken.metric.speed", "km/h"), ""))
-	require.Equal(t, "astro_light_speed_limit_meters_per_second", normalizeName(createGauge("astro.light.speed_limit", "m/s"), ""))
+	require.Equal(t, "broken_metric_speed_km_per_hour", normalizeName(createGauge("broken.metric.speed", "km/h"), "", false))
+	require.Equal(t, "astro_light_speed_limit_meters_per_second", normalizeName(createGauge("astro.light.speed_limit", "m/s"), "", false))
 }

 func TestPercent(t *testing.T) {
-	require.Equal(t, "broken_metric_success_ratio_percent", normalizeName(createGauge("broken.metric.success_ratio", "%"), ""))
-	require.Equal(t, "broken_metric_success_percent", normalizeName(createGauge("broken.metric.success_percent", "%"), ""))
+	require.Equal(t, "broken_metric_success_ratio_percent", normalizeName(createGauge("broken.metric.success_ratio", "%"), "", false))
+	require.Equal(t, "broken_metric_success_percent", normalizeName(createGauge("broken.metric.success_percent", "%"), "", false))
 }

 func TestEmpty(t *testing.T) {
-	require.Equal(t, "test_metric_no_unit", normalizeName(createGauge("test.metric.no_unit", ""), ""))
-	require.Equal(t, "test_metric_spaces", normalizeName(createGauge("test.metric.spaces", "   \t  "), ""))
+	require.Equal(t, "test_metric_no_unit", normalizeName(createGauge("test.metric.no_unit", ""), "", false))
+	require.Equal(t, "test_metric_spaces", normalizeName(createGauge("test.metric.spaces", "   \t  "), "", false))
 }

-func TestUnsupportedRunes(t *testing.T) {
-	require.Equal(t, "unsupported_metric_temperature_F", normalizeName(createGauge("unsupported.metric.temperature", "°F"), ""))
-	require.Equal(t, "unsupported_metric_weird", normalizeName(createGauge("unsupported.metric.weird", "+=.:,!* & #"), ""))
-	require.Equal(t, "unsupported_metric_redundant_test_per_C", normalizeName(createGauge("unsupported.metric.redundant", "__test $/°C"), ""))
+func TestAllowUTF8(t *testing.T) {
+	t.Run("allow UTF8", func(t *testing.T) {
+		require.Equal(t, "unsupported.metric.temperature_°F", normalizeName(createGauge("unsupported.metric.temperature", "°F"), "", true))
+		require.Equal(t, "unsupported.metric.weird_+=.:,!* & #", normalizeName(createGauge("unsupported.metric.weird", "+=.:,!* & #"), "", true))
+		require.Equal(t, "unsupported.metric.redundant___test $_per_°C", normalizeName(createGauge("unsupported.metric.redundant", "__test $/°C"), "", true))
+		require.Equal(t, "metric_with_字符_foreign_characters_ど", normalizeName(createGauge("metric_with_字符_foreign_characters", "ど"), "", true))
+	})
+	t.Run("disallow UTF8", func(t *testing.T) {
+		require.Equal(t, "unsupported_metric_temperature_F", normalizeName(createGauge("unsupported.metric.temperature", "°F"), "", false))
+		require.Equal(t, "unsupported_metric_weird", normalizeName(createGauge("unsupported.metric.weird", "+=.:,!* & #"), "", false))
+		require.Equal(t, "unsupported_metric_redundant_test_per_C", normalizeName(createGauge("unsupported.metric.redundant", "__test $/°C"), "", false))
+		require.Equal(t, "metric_with_foreign_characters", normalizeName(createGauge("metric_with_字符_foreign_characters", "ど"), "", false))
+	})
+}
+
+func TestAllowUTF8KnownBugs(t *testing.T) {
+	// Due to historical reasons, the translator code was copied from OpenTelemetry collector codebase.
+	// Over there, they tried to provide means to translate metric names following Prometheus conventions that are documented here:
+	// https://prometheus.io/docs/practices/naming/
+	//
+	// Althogh not explicitly said, it was implied that words should be separated by a single underscore and the codebase was written
+	// with that in mind.
+	//
+	// Now that we're allowing OTel users to have their original names stored in prometheus without any transformation, we're facing problems
+	// where two (or more) UTF-8 characters are being used to separate words.
+	// TODO(arthursens): Fix it!
+
+	// We're asserting on 'NotEqual', which proves the bug.
+	require.NotEqual(t, "metric....split_=+by_//utf8characters", normalizeName(createGauge("metric....split_=+by_//utf8characters", ""), "", true))
+	// Here we're asserting on 'Equal', showing the current behavior.
+	require.Equal(t, "metric.split_by_utf8characters", normalizeName(createGauge("metric....split_=+by_//utf8characters", ""), "", true))
 }

 func TestOTelReceivers(t *testing.T) {
-	require.Equal(t, "active_directory_ds_replication_network_io_bytes_total", normalizeName(createCounter("active_directory.ds.replication.network.io", "By"), ""))
-	require.Equal(t, "active_directory_ds_replication_sync_object_pending_total", normalizeName(createCounter("active_directory.ds.replication.sync.object.pending", "{objects}"), ""))
-	require.Equal(t, "active_directory_ds_replication_object_rate_per_second", normalizeName(createGauge("active_directory.ds.replication.object.rate", "{objects}/s"), ""))
-	require.Equal(t, "active_directory_ds_name_cache_hit_rate_percent", normalizeName(createGauge("active_directory.ds.name_cache.hit_rate", "%"), ""))
-	require.Equal(t, "active_directory_ds_ldap_bind_last_successful_time_milliseconds", normalizeName(createGauge("active_directory.ds.ldap.bind.last_successful.time", "ms"), ""))
-	require.Equal(t, "apache_current_connections", normalizeName(createGauge("apache.current_connections", "connections"), ""))
-	require.Equal(t, "apache_workers_connections", normalizeName(createGauge("apache.workers", "connections"), ""))
-	require.Equal(t, "apache_requests_total", normalizeName(createCounter("apache.requests", "1"), ""))
-	require.Equal(t, "bigip_virtual_server_request_count_total", normalizeName(createCounter("bigip.virtual_server.request.count", "{requests}"), ""))
-	require.Equal(t, "system_cpu_utilization_ratio", normalizeName(createGauge("system.cpu.utilization", "1"), ""))
-	require.Equal(t, "system_disk_operation_time_seconds_total", normalizeName(createCounter("system.disk.operation_time", "s"), ""))
-	require.Equal(t, "system_cpu_load_average_15m_ratio", normalizeName(createGauge("system.cpu.load_average.15m", "1"), ""))
-	require.Equal(t, "memcached_operation_hit_ratio_percent", normalizeName(createGauge("memcached.operation_hit_ratio", "%"), ""))
-	require.Equal(t, "mongodbatlas_process_asserts_per_second", normalizeName(createGauge("mongodbatlas.process.asserts", "{assertions}/s"), ""))
-	require.Equal(t, "mongodbatlas_process_journaling_data_files_mebibytes", normalizeName(createGauge("mongodbatlas.process.journaling.data_files", "MiBy"), ""))
-	require.Equal(t, "mongodbatlas_process_network_io_bytes_per_second", normalizeName(createGauge("mongodbatlas.process.network.io", "By/s"), ""))
-	require.Equal(t, "mongodbatlas_process_oplog_rate_gibibytes_per_hour", normalizeName(createGauge("mongodbatlas.process.oplog.rate", "GiBy/h"), ""))
-	require.Equal(t, "mongodbatlas_process_db_query_targeting_scanned_per_returned", normalizeName(createGauge("mongodbatlas.process.db.query_targeting.scanned_per_returned", "{scanned}/{returned}"), ""))
-	require.Equal(t, "nginx_requests", normalizeName(createGauge("nginx.requests", "requests"), ""))
-	require.Equal(t, "nginx_connections_accepted", normalizeName(createGauge("nginx.connections_accepted", "connections"), ""))
-	require.Equal(t, "nsxt_node_memory_usage_kilobytes", normalizeName(createGauge("nsxt.node.memory.usage", "KBy"), ""))
-	require.Equal(t, "redis_latest_fork_microseconds", normalizeName(createGauge("redis.latest_fork", "us"), ""))
+	require.Equal(t, "active_directory_ds_replication_network_io_bytes_total", normalizeName(createCounter("active_directory.ds.replication.network.io", "By"), "", false))
+	require.Equal(t, "active_directory_ds_replication_sync_object_pending_total", normalizeName(createCounter("active_directory.ds.replication.sync.object.pending", "{objects}"), "", false))
+	require.Equal(t, "active_directory_ds_replication_object_rate_per_second", normalizeName(createGauge("active_directory.ds.replication.object.rate", "{objects}/s"), "", false))
+	require.Equal(t, "active_directory_ds_name_cache_hit_rate_percent", normalizeName(createGauge("active_directory.ds.name_cache.hit_rate", "%"), "", false))
+	require.Equal(t, "active_directory_ds_ldap_bind_last_successful_time_milliseconds", normalizeName(createGauge("active_directory.ds.ldap.bind.last_successful.time", "ms"), "", false))
+	require.Equal(t, "apache_current_connections", normalizeName(createGauge("apache.current_connections", "connections"), "", false))
+	require.Equal(t, "apache_workers_connections", normalizeName(createGauge("apache.workers", "connections"), "", false))
+	require.Equal(t, "apache_requests_total", normalizeName(createCounter("apache.requests", "1"), "", false))
+	require.Equal(t, "bigip_virtual_server_request_count_total", normalizeName(createCounter("bigip.virtual_server.request.count", "{requests}"), "", false))
+	require.Equal(t, "system_cpu_utilization_ratio", normalizeName(createGauge("system.cpu.utilization", "1"), "", false))
+	require.Equal(t, "system_disk_operation_time_seconds_total", normalizeName(createCounter("system.disk.operation_time", "s"), "", false))
+	require.Equal(t, "system_cpu_load_average_15m_ratio", normalizeName(createGauge("system.cpu.load_average.15m", "1"), "", false))
+	require.Equal(t, "memcached_operation_hit_ratio_percent", normalizeName(createGauge("memcached.operation_hit_ratio", "%"), "", false))
+	require.Equal(t, "mongodbatlas_process_asserts_per_second", normalizeName(createGauge("mongodbatlas.process.asserts", "{assertions}/s"), "", false))
+	require.Equal(t, "mongodbatlas_process_journaling_data_files_mebibytes", normalizeName(createGauge("mongodbatlas.process.journaling.data_files", "MiBy"), "", false))
+	require.Equal(t, "mongodbatlas_process_network_io_bytes_per_second", normalizeName(createGauge("mongodbatlas.process.network.io", "By/s"), "", false))
+	require.Equal(t, "mongodbatlas_process_oplog_rate_gibibytes_per_hour", normalizeName(createGauge("mongodbatlas.process.oplog.rate", "GiBy/h"), "", false))
+	require.Equal(t, "mongodbatlas_process_db_query_targeting_scanned_per_returned", normalizeName(createGauge("mongodbatlas.process.db.query_targeting.scanned_per_returned", "{scanned}/{returned}"), "", false))
+	require.Equal(t, "nginx_requests", normalizeName(createGauge("nginx.requests", "requests"), "", false))
+	require.Equal(t, "nginx_connections_accepted", normalizeName(createGauge("nginx.connections_accepted", "connections"), "", false))
+	require.Equal(t, "nsxt_node_memory_usage_kilobytes", normalizeName(createGauge("nsxt.node.memory.usage", "KBy"), "", false))
+	require.Equal(t, "redis_latest_fork_microseconds", normalizeName(createGauge("redis.latest_fork", "us"), "", false))
 }

 func TestTrimPromSuffixes(t *testing.T) {
@ -144,8 +171,8 @@ func TestTrimPromSuffixes(t *testing.T) {
 }

 func TestNamespace(t *testing.T) {
-	require.Equal(t, "space_test", normalizeName(createGauge("test", ""), "space"))
-	require.Equal(t, "space_test", normalizeName(createGauge("#test", ""), "space"))
+	require.Equal(t, "space_test", normalizeName(createGauge("test", ""), "space", false))
+	require.Equal(t, "space_test", normalizeName(createGauge("#test", ""), "space", false))
 }

 func TestCleanUpUnit(t *testing.T) {
@ -180,28 +207,28 @@ func TestRemoveItem(t *testing.T) {
 }

 func TestBuildCompliantNameWithSuffixes(t *testing.T) {
-	require.Equal(t, "system_io_bytes_total", BuildCompliantName(createCounter("system.io", "By"), "", true))
-	require.Equal(t, "system_network_io_bytes_total", BuildCompliantName(createCounter("network.io", "By"), "system", true))
-	require.Equal(t, "_3_14_digits", BuildCompliantName(createGauge("3.14 digits", ""), "", true))
-	require.Equal(t, "envoy_rule_engine_zlib_buf_error", BuildCompliantName(createGauge("envoy__rule_engine_zlib_buf_error", ""), "", true))
-	require.Equal(t, ":foo::bar", BuildCompliantName(createGauge(":foo::bar", ""), "", true))
-	require.Equal(t, ":foo::bar_total", BuildCompliantName(createCounter(":foo::bar", ""), "", true))
+	require.Equal(t, "system_io_bytes_total", BuildCompliantName(createCounter("system.io", "By"), "", true, false))
+	require.Equal(t, "system_network_io_bytes_total", BuildCompliantName(createCounter("network.io", "By"), "system", true, false))
+	require.Equal(t, "_3_14_digits", BuildCompliantName(createGauge("3.14 digits", ""), "", true, false))
+	require.Equal(t, "envoy_rule_engine_zlib_buf_error", BuildCompliantName(createGauge("envoy__rule_engine_zlib_buf_error", ""), "", true, false))
+	require.Equal(t, ":foo::bar", BuildCompliantName(createGauge(":foo::bar", ""), "", true, false))
+	require.Equal(t, ":foo::bar_total", BuildCompliantName(createCounter(":foo::bar", ""), "", true, false))
 	// Gauges with unit 1 are considered ratios.
-	require.Equal(t, "foo_bar_ratio", BuildCompliantName(createGauge("foo.bar", "1"), "", true))
+	require.Equal(t, "foo_bar_ratio", BuildCompliantName(createGauge("foo.bar", "1"), "", true, false))
 	// Slashes in units are converted.
-	require.Equal(t, "system_io_foo_per_bar_total", BuildCompliantName(createCounter("system.io", "foo/bar"), "", true))
-	require.Equal(t, "metric_with_foreign_characters_total", BuildCompliantName(createCounter("metric_with_字符_foreign_characters", ""), "", true))
+	require.Equal(t, "system_io_foo_per_bar_total", BuildCompliantName(createCounter("system.io", "foo/bar"), "", true, false))
+	require.Equal(t, "metric_with_foreign_characters_total", BuildCompliantName(createCounter("metric_with_字符_foreign_characters", ""), "", true, false))
 }

 func TestBuildCompliantNameWithoutSuffixes(t *testing.T) {
-	require.Equal(t, "system_io", BuildCompliantName(createCounter("system.io", "By"), "", false))
-	require.Equal(t, "system_network_io", BuildCompliantName(createCounter("network.io", "By"), "system", false))
-	require.Equal(t, "system_network_I_O", BuildCompliantName(createCounter("network (I/O)", "By"), "system", false))
-	require.Equal(t, "_3_14_digits", BuildCompliantName(createGauge("3.14 digits", "By"), "", false))
-	require.Equal(t, "envoy__rule_engine_zlib_buf_error", BuildCompliantName(createGauge("envoy__rule_engine_zlib_buf_error", ""), "", false))
-	require.Equal(t, ":foo::bar", BuildCompliantName(createGauge(":foo::bar", ""), "", false))
-	require.Equal(t, ":foo::bar", BuildCompliantName(createCounter(":foo::bar", ""), "", false))
-	require.Equal(t, "foo_bar", BuildCompliantName(createGauge("foo.bar", "1"), "", false))
-	require.Equal(t, "system_io", BuildCompliantName(createCounter("system.io", "foo/bar"), "", false))
-	require.Equal(t, "metric_with___foreign_characters", BuildCompliantName(createCounter("metric_with_字符_foreign_characters", ""), "", false))
+	require.Equal(t, "system_io", BuildCompliantName(createCounter("system.io", "By"), "", false, false))
+	require.Equal(t, "system_network_io", BuildCompliantName(createCounter("network.io", "By"), "system", false, false))
+	require.Equal(t, "system_network_I_O", BuildCompliantName(createCounter("network (I/O)", "By"), "system", false, false))
+	require.Equal(t, "_3_14_digits", BuildCompliantName(createGauge("3.14 digits", "By"), "", false, false))
+	require.Equal(t, "envoy__rule_engine_zlib_buf_error", BuildCompliantName(createGauge("envoy__rule_engine_zlib_buf_error", ""), "", false, false))
+	require.Equal(t, ":foo::bar", BuildCompliantName(createGauge(":foo::bar", ""), "", false, false))
+	require.Equal(t, ":foo::bar", BuildCompliantName(createCounter(":foo::bar", ""), "", false, false))
+	require.Equal(t, "foo_bar", BuildCompliantName(createGauge("foo.bar", "1"), "", false, false))
+	require.Equal(t, "system_io", BuildCompliantName(createCounter("system.io", "foo/bar"), "", false, false))
+	require.Equal(t, "metric_with___foreign_characters", BuildCompliantName(createCounter("metric_with_字符_foreign_characters", ""), "", false, false))
 }
--- a/storage/remote/otlptranslator/prometheusremotewrite/helper.go
+++ b/storage/remote/otlptranslator/prometheusremotewrite/helper.go
@ -157,7 +157,7 @@ func createAttributes(resource pcommon.Resource, attributes pcommon.Map, setting
 	// map ensures no duplicate label names.
 	l := make(map[string]string, maxLabelCount)
 	for _, label := range labels {
-		var finalKey = prometheustranslator.NormalizeLabel(label.Name)
+		var finalKey = prometheustranslator.NormalizeLabel(label.Name, settings.AllowUTF8)
 		if existingValue, alreadyExists := l[finalKey]; alreadyExists {
 			l[finalKey] = existingValue + ";" + label.Value
 		} else {
@ -166,7 +166,7 @@ func createAttributes(resource pcommon.Resource, attributes pcommon.Map, setting
 	}

 	for _, lbl := range promotedAttrs {
-		normalized := prometheustranslator.NormalizeLabel(lbl.Name)
+		normalized := prometheustranslator.NormalizeLabel(lbl.Name, settings.AllowUTF8)
 		if _, exists := l[normalized]; !exists {
 			l[normalized] = lbl.Value
 		}
@ -205,7 +205,7 @@ func createAttributes(resource pcommon.Resource, attributes pcommon.Map, setting
 		}
 		// internal labels should be maintained
 		if !(len(name) > 4 && name[:2] == "__" && name[len(name)-2:] == "__") {
-			name = prometheustranslator.NormalizeLabel(name)
+			name = prometheustranslator.NormalizeLabel(name, settings.AllowUTF8)
 		}
 		l[name] = extras[i+1]
 	}
--- a/storage/remote/otlptranslator/prometheusremotewrite/histograms_test.go
+++ b/storage/remote/otlptranslator/prometheusremotewrite/histograms_test.go
@ -762,7 +762,7 @@ func TestPrometheusConverter_addExponentialHistogramDataPoints(t *testing.T) {
 				Settings{
 					ExportCreatedMetric: true,
 				},
-				prometheustranslator.BuildCompliantName(metric, "", true),
+				prometheustranslator.BuildCompliantName(metric, "", true, true),
 			)
 			require.NoError(t, err)
 			require.Empty(t, annots)
--- a/storage/remote/otlptranslator/prometheusremotewrite/metrics_to_prw.go
+++ b/storage/remote/otlptranslator/prometheusremotewrite/metrics_to_prw.go
@ -38,6 +38,7 @@ type Settings struct {
 	ExportCreatedMetric       bool
 	AddMetricSuffixes         bool
 	SendMetadata              bool
+	AllowUTF8                 bool
 	PromoteResourceAttributes []string
 }

@ -84,7 +85,7 @@ func (c *PrometheusConverter) FromMetrics(ctx context.Context, md pmetric.Metric
 					continue
 				}

-				promName := prometheustranslator.BuildCompliantName(metric, settings.Namespace, settings.AddMetricSuffixes)
+				promName := prometheustranslator.BuildCompliantName(metric, settings.Namespace, settings.AddMetricSuffixes, settings.AllowUTF8)

 				// handle individual metrics based on type
 				//exhaustive:enforce
--- a/storage/remote/otlptranslator/prometheusremotewrite/otlp_to_openmetrics_metadata.go
+++ b/storage/remote/otlptranslator/prometheusremotewrite/otlp_to_openmetrics_metadata.go
@ -43,7 +43,7 @@ func otelMetricTypeToPromMetricType(otelMetric pmetric.Metric) prompb.MetricMeta
 	return prompb.MetricMetadata_UNKNOWN
 }

-func OtelMetricsToMetadata(md pmetric.Metrics, addMetricSuffixes bool) []*prompb.MetricMetadata {
+func OtelMetricsToMetadata(md pmetric.Metrics, addMetricSuffixes, allowUTF8 bool) []*prompb.MetricMetadata {
 	resourceMetricsSlice := md.ResourceMetrics()

 	metadataLength := 0
@ -65,7 +65,7 @@ func OtelMetricsToMetadata(md pmetric.Metrics, addMetricSuffixes bool) []*prompb
 				metric := scopeMetrics.Metrics().At(k)
 				entry := prompb.MetricMetadata{
 					Type:             otelMetricTypeToPromMetricType(metric),
-					MetricFamilyName: prometheustranslator.BuildCompliantName(metric, "", addMetricSuffixes),
+					MetricFamilyName: prometheustranslator.BuildCompliantName(metric, "", addMetricSuffixes, allowUTF8),
 					Help:             metric.Description(),
 				}
 				metadata = append(metadata, &entry)
--- a/storage/remote/write_handler.go
+++ b/storage/remote/write_handler.go
@ -513,6 +513,7 @@ func (h *otlpWriteHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	converter := otlptranslator.NewPrometheusConverter()
 	annots, err := converter.FromMetrics(r.Context(), req.Metrics(), otlptranslator.Settings{
 		AddMetricSuffixes:         true,
+		AllowUTF8:                 otlpCfg.TranslationStrategy == config.NoUTF8EscapingWithSuffixes,
 		PromoteResourceAttributes: otlpCfg.PromoteResourceAttributes,
 	})
 	if err != nil {
--- a/web/ui/mantine-ui/package.json
+++ b/web/ui/mantine-ui/package.json
@ -1,7 +1,7 @@
 {
  "name": "@prometheus-io/mantine-ui",
  "private": true,
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "type": "module",
  "scripts": {
    "start": "vite",
@ -28,7 +28,7 @@
    "@microsoft/fetch-event-source": "^2.0.1",
    "@nexucis/fuzzy": "^0.5.1",
    "@nexucis/kvsearch": "^0.9.1",
-    "@prometheus-io/codemirror-promql": "0.300.0-rc.0",
+    "@prometheus-io/codemirror-promql": "0.300.0-rc.1",
    "@reduxjs/toolkit": "^2.2.1",
    "@tabler/icons-react": "^3.19.0",
    "@tanstack/react-query": "^5.59.0",
--- a/web/ui/module/codemirror-promql/package.json
+++ b/web/ui/module/codemirror-promql/package.json
@ -1,6 +1,6 @@
 {
  "name": "@prometheus-io/codemirror-promql",
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "description": "a CodeMirror mode for the PromQL language",
  "types": "dist/esm/index.d.ts",
  "module": "dist/esm/index.js",
@ -29,7 +29,7 @@
  },
  "homepage": "https://github.com/prometheus/prometheus/blob/main/web/ui/module/codemirror-promql/README.md",
  "dependencies": {
-    "@prometheus-io/lezer-promql": "0.300.0-rc.0",
+    "@prometheus-io/lezer-promql": "0.300.0-rc.1",
    "lru-cache": "^11.0.1"
  },
  "devDependencies": {
--- a/web/ui/module/lezer-promql/package.json
+++ b/web/ui/module/lezer-promql/package.json
@ -1,6 +1,6 @@
 {
  "name": "@prometheus-io/lezer-promql",
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "description": "lezer-based PromQL grammar",
  "main": "dist/index.cjs",
  "type": "module",
--- a/web/ui/package-lock.json
+++ b/web/ui/package-lock.json
@ -1,12 +1,12 @@
 {
  "name": "prometheus-io",
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "prometheus-io",
-      "version": "0.300.0-rc.0",
+      "version": "0.300.0-rc.1",
      "workspaces": [
        "mantine-ui",
        "module/*"
@ -24,7 +24,7 @@
    },
    "mantine-ui": {
      "name": "@prometheus-io/mantine-ui",
-      "version": "0.300.0-rc.0",
+      "version": "0.300.0-rc.1",
      "dependencies": {
        "@codemirror/autocomplete": "^6.18.1",
        "@codemirror/language": "^6.10.2",
@ -42,7 +42,7 @@
        "@microsoft/fetch-event-source": "^2.0.1",
        "@nexucis/fuzzy": "^0.5.1",
        "@nexucis/kvsearch": "^0.9.1",
-        "@prometheus-io/codemirror-promql": "0.300.0-rc.0",
+        "@prometheus-io/codemirror-promql": "0.300.0-rc.1",
        "@reduxjs/toolkit": "^2.2.1",
        "@tabler/icons-react": "^3.19.0",
        "@tanstack/react-query": "^5.59.0",
@ -155,10 +155,10 @@
    },
    "module/codemirror-promql": {
      "name": "@prometheus-io/codemirror-promql",
-      "version": "0.300.0-rc.0",
+      "version": "0.300.0-rc.1",
      "license": "Apache-2.0",
      "dependencies": {
-        "@prometheus-io/lezer-promql": "0.300.0-rc.0",
+        "@prometheus-io/lezer-promql": "0.300.0-rc.1",
        "lru-cache": "^11.0.1"
      },
      "devDependencies": {
@ -188,7 +188,7 @@
    },
    "module/lezer-promql": {
      "name": "@prometheus-io/lezer-promql",
-      "version": "0.300.0-rc.0",
+      "version": "0.300.0-rc.1",
      "license": "Apache-2.0",
      "devDependencies": {
        "@lezer/generator": "^1.7.1",
--- a/web/ui/package.json
+++ b/web/ui/package.json
@ -1,7 +1,7 @@
 {
  "name": "prometheus-io",
  "description": "Monorepo for the Prometheus UI",
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "private": true,
  "scripts": {
    "build": "bash build_ui.sh --all",
--- a/web/ui/react-app/package-lock.json
+++ b/web/ui/react-app/package-lock.json
@ -1,12 +1,12 @@
 {
  "name": "@prometheus-io/app",
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "@prometheus-io/app",
-      "version": "0.300.0-rc.0",
+      "version": "0.300.0-rc.1",
      "dependencies": {
        "@codemirror/autocomplete": "^6.17.0",
        "@codemirror/commands": "^6.6.0",
--- a/web/ui/react-app/package.json
+++ b/web/ui/react-app/package.json
@ -1,6 +1,6 @@
 {
  "name": "@prometheus-io/app",
-  "version": "0.300.0-rc.0",
+  "version": "0.300.0-rc.1",
  "private": true,
  "dependencies": {
    "@codemirror/autocomplete": "^6.17.0",