prometheusreceiver: Add trim_metric_suffixes configuration option (#24256)

**Description:**

Adds a new configuration option: `trim_metric_suffixes` to the
prometheus receiver. When set to true, suffixes will be trimmed from
metrics. This replaces use of
the`pkg.translator.prometheus.NormalizeName` feature-gate in the
prometheus receiver, but leaves it for exporters.

The first commit simplifies the usage of the feature-gate. The tests and
implementation were passing around an entire registry when it wasn't
necessary.

**Link to tracking Issue:**

Part of
#21743
Part of
#8950

Author: dashpole

.chloggen/prometheus-receiver-normalization-config.yaml

@@ -0,0 +1,23 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'breaking'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: prometheusreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add the `trim_metric_suffixes` configuration option to allow enable metric suffix trimming."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [21743, 8950]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: | 
+  When enabled, suffixes for unit and type are trimmed from metric names. 
+  If you previously enabled the `pkg.translator.prometheus.NormalizeName` 
+  feature gate, you will need to enable this option to have suffixes trimmed.

pkg/translator/prometheus/normalize_name.go

@@ -177,36 +177,11 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 	return normalizedName
 }
 
-type Normalizer struct {
-	gate *featuregate.Gate
-}
-
-func NewNormalizer(registry *featuregate.Registry) *Normalizer {
-	var normalizeGate *featuregate.Gate
-	registry.VisitAll(func(gate *featuregate.Gate) {
-		if gate.ID() == normalizeNameGate.ID() {
-			normalizeGate = gate
-		}
-	})
-	// the registry didn't contain the flag, fallback to the global
-	// flag. Overriding the registry is really only done in tests
-	if normalizeGate == nil {
-		normalizeGate = normalizeNameGate
-	}
-	return &Normalizer{
-		gate: normalizeGate,
-	}
-}
-
 // TrimPromSuffixes trims type and unit prometheus suffixes from a metric name.
 // Following the [OpenTelemetry specs] for converting Prometheus Metric points to OTLP.
 //
 // [OpenTelemetry specs]: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/data-model.md#metric-metadata
-func (n *Normalizer) TrimPromSuffixes(promName string, metricType pmetric.MetricType, unit string) string {
-	if !n.gate.IsEnabled() {
-		return promName
-	}
-
+func TrimPromSuffixes(promName string, metricType pmetric.MetricType, unit string) string {
 	nameTokens := strings.Split(promName, "_")
 	if len(nameTokens) == 1 {
 		return promName

pkg/translator/prometheus/normalize_name_test.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"go.opentelemetry.io/collector/featuregate"
 	"go.opentelemetry.io/collector/pdata/pmetric"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/common/testutil"
@@ -139,48 +138,36 @@ func TestOtelReceivers(t *testing.T) {
 }
 
 func TestTrimPromSuffixes(t *testing.T) {
-	registry := featuregate.NewRegistry()
-	_, err := registry.Register(normalizeNameGate.ID(), featuregate.StageBeta)
-	require.NoError(t, err)
-	normalizer := NewNormalizer(registry)
-
-	assert.Equal(t, "active_directory_ds_replication_network_io", normalizer.TrimPromSuffixes("active_directory_ds_replication_network_io_bytes_total", pmetric.MetricTypeSum, "bytes"))
-	assert.Equal(t, "active_directory_ds_name_cache_hit_rate", normalizer.TrimPromSuffixes("active_directory_ds_name_cache_hit_rate_percent", pmetric.MetricTypeGauge, "percent"))
-	assert.Equal(t, "active_directory_ds_ldap_bind_last_successful_time", normalizer.TrimPromSuffixes("active_directory_ds_ldap_bind_last_successful_time_milliseconds", pmetric.MetricTypeGauge, "milliseconds"))
-	assert.Equal(t, "apache_requests", normalizer.TrimPromSuffixes("apache_requests_total", pmetric.MetricTypeSum, "1"))
-	assert.Equal(t, "system_cpu_utilization", normalizer.TrimPromSuffixes("system_cpu_utilization_ratio", pmetric.MetricTypeGauge, "ratio"))
-	assert.Equal(t, "mongodbatlas_process_journaling_data_files", normalizer.TrimPromSuffixes("mongodbatlas_process_journaling_data_files_mebibytes", pmetric.MetricTypeGauge, "mebibytes"))
-	assert.Equal(t, "mongodbatlas_process_network_io", normalizer.TrimPromSuffixes("mongodbatlas_process_network_io_bytes_per_second", pmetric.MetricTypeGauge, "bytes_per_second"))
-	assert.Equal(t, "mongodbatlas_process_oplog_rate", normalizer.TrimPromSuffixes("mongodbatlas_process_oplog_rate_gibibytes_per_hour", pmetric.MetricTypeGauge, "gibibytes_per_hour"))
-	assert.Equal(t, "nsxt_node_memory_usage", normalizer.TrimPromSuffixes("nsxt_node_memory_usage_kilobytes", pmetric.MetricTypeGauge, "kilobytes"))
-	assert.Equal(t, "redis_latest_fork", normalizer.TrimPromSuffixes("redis_latest_fork_microseconds", pmetric.MetricTypeGauge, "microseconds"))
-	assert.Equal(t, "up", normalizer.TrimPromSuffixes("up", pmetric.MetricTypeGauge, ""))
+	assert.Equal(t, "active_directory_ds_replication_network_io", TrimPromSuffixes("active_directory_ds_replication_network_io_bytes_total", pmetric.MetricTypeSum, "bytes"))
+	assert.Equal(t, "active_directory_ds_name_cache_hit_rate", TrimPromSuffixes("active_directory_ds_name_cache_hit_rate_percent", pmetric.MetricTypeGauge, "percent"))
+	assert.Equal(t, "active_directory_ds_ldap_bind_last_successful_time", TrimPromSuffixes("active_directory_ds_ldap_bind_last_successful_time_milliseconds", pmetric.MetricTypeGauge, "milliseconds"))
+	assert.Equal(t, "apache_requests", TrimPromSuffixes("apache_requests_total", pmetric.MetricTypeSum, "1"))
+	assert.Equal(t, "system_cpu_utilization", TrimPromSuffixes("system_cpu_utilization_ratio", pmetric.MetricTypeGauge, "ratio"))
+	assert.Equal(t, "mongodbatlas_process_journaling_data_files", TrimPromSuffixes("mongodbatlas_process_journaling_data_files_mebibytes", pmetric.MetricTypeGauge, "mebibytes"))
+	assert.Equal(t, "mongodbatlas_process_network_io", TrimPromSuffixes("mongodbatlas_process_network_io_bytes_per_second", pmetric.MetricTypeGauge, "bytes_per_second"))
+	assert.Equal(t, "mongodbatlas_process_oplog_rate", TrimPromSuffixes("mongodbatlas_process_oplog_rate_gibibytes_per_hour", pmetric.MetricTypeGauge, "gibibytes_per_hour"))
+	assert.Equal(t, "nsxt_node_memory_usage", TrimPromSuffixes("nsxt_node_memory_usage_kilobytes", pmetric.MetricTypeGauge, "kilobytes"))
+	assert.Equal(t, "redis_latest_fork", TrimPromSuffixes("redis_latest_fork_microseconds", pmetric.MetricTypeGauge, "microseconds"))
+	assert.Equal(t, "up", TrimPromSuffixes("up", pmetric.MetricTypeGauge, ""))
 
 	// These are not necessarily valid OM units, only tested for the sake of completeness.
-	assert.Equal(t, "active_directory_ds_replication_sync_object_pending", normalizer.TrimPromSuffixes("active_directory_ds_replication_sync_object_pending_total", pmetric.MetricTypeSum, "{objects}"))
-	assert.Equal(t, "apache_current", normalizer.TrimPromSuffixes("apache_current_connections", pmetric.MetricTypeGauge, "connections"))
-	assert.Equal(t, "bigip_virtual_server_request_count", normalizer.TrimPromSuffixes("bigip_virtual_server_request_count_total", pmetric.MetricTypeSum, "{requests}"))
-	assert.Equal(t, "mongodbatlas_process_db_query_targeting_scanned_per_returned", normalizer.TrimPromSuffixes("mongodbatlas_process_db_query_targeting_scanned_per_returned", pmetric.MetricTypeGauge, "{scanned}/{returned}"))
-	assert.Equal(t, "nginx_connections_accepted", normalizer.TrimPromSuffixes("nginx_connections_accepted", pmetric.MetricTypeGauge, "connections"))
-	assert.Equal(t, "apache_workers", normalizer.TrimPromSuffixes("apache_workers_connections", pmetric.MetricTypeGauge, "connections"))
-	assert.Equal(t, "nginx", normalizer.TrimPromSuffixes("nginx_requests", pmetric.MetricTypeGauge, "requests"))
+	assert.Equal(t, "active_directory_ds_replication_sync_object_pending", TrimPromSuffixes("active_directory_ds_replication_sync_object_pending_total", pmetric.MetricTypeSum, "{objects}"))
+	assert.Equal(t, "apache_current", TrimPromSuffixes("apache_current_connections", pmetric.MetricTypeGauge, "connections"))
+	assert.Equal(t, "bigip_virtual_server_request_count", TrimPromSuffixes("bigip_virtual_server_request_count_total", pmetric.MetricTypeSum, "{requests}"))
+	assert.Equal(t, "mongodbatlas_process_db_query_targeting_scanned_per_returned", TrimPromSuffixes("mongodbatlas_process_db_query_targeting_scanned_per_returned", pmetric.MetricTypeGauge, "{scanned}/{returned}"))
+	assert.Equal(t, "nginx_connections_accepted", TrimPromSuffixes("nginx_connections_accepted", pmetric.MetricTypeGauge, "connections"))
+	assert.Equal(t, "apache_workers", TrimPromSuffixes("apache_workers_connections", pmetric.MetricTypeGauge, "connections"))
+	assert.Equal(t, "nginx", TrimPromSuffixes("nginx_requests", pmetric.MetricTypeGauge, "requests"))
 
 	// Units shouldn't be trimmed if the unit is not a direct match with the suffix, i.e, a suffix "_seconds" shouldn't be removed if unit is "sec" or "s"
-	assert.Equal(t, "system_cpu_load_average_15m_ratio", normalizer.TrimPromSuffixes("system_cpu_load_average_15m_ratio", pmetric.MetricTypeGauge, "1"))
-	assert.Equal(t, "mongodbatlas_process_asserts_per_second", normalizer.TrimPromSuffixes("mongodbatlas_process_asserts_per_second", pmetric.MetricTypeGauge, "{assertions}/s"))
-	assert.Equal(t, "memcached_operation_hit_ratio_percent", normalizer.TrimPromSuffixes("memcached_operation_hit_ratio_percent", pmetric.MetricTypeGauge, "%"))
-	assert.Equal(t, "active_directory_ds_replication_object_rate_per_second", normalizer.TrimPromSuffixes("active_directory_ds_replication_object_rate_per_second", pmetric.MetricTypeGauge, "{objects}/s"))
-	assert.Equal(t, "system_disk_operation_time_seconds", normalizer.TrimPromSuffixes("system_disk_operation_time_seconds_total", pmetric.MetricTypeSum, "s"))
+	assert.Equal(t, "system_cpu_load_average_15m_ratio", TrimPromSuffixes("system_cpu_load_average_15m_ratio", pmetric.MetricTypeGauge, "1"))
+	assert.Equal(t, "mongodbatlas_process_asserts_per_second", TrimPromSuffixes("mongodbatlas_process_asserts_per_second", pmetric.MetricTypeGauge, "{assertions}/s"))
+	assert.Equal(t, "memcached_operation_hit_ratio_percent", TrimPromSuffixes("memcached_operation_hit_ratio_percent", pmetric.MetricTypeGauge, "%"))
+	assert.Equal(t, "active_directory_ds_replication_object_rate_per_second", TrimPromSuffixes("active_directory_ds_replication_object_rate_per_second", pmetric.MetricTypeGauge, "{objects}/s"))
+	assert.Equal(t, "system_disk_operation_time_seconds", TrimPromSuffixes("system_disk_operation_time_seconds_total", pmetric.MetricTypeSum, "s"))
 
 }
 
-func TestTrimPromSuffixesWithFeatureGateDisabled(t *testing.T) {
-	normalizer := NewNormalizer(featuregate.NewRegistry())
-
-	assert.Equal(t, "apache_current_connections", normalizer.TrimPromSuffixes("apache_current_connections", pmetric.MetricTypeGauge, "connections"))
-	assert.Equal(t, "apache_requests_total", normalizer.TrimPromSuffixes("apache_requests_total", pmetric.MetricTypeSum, "1"))
-}
-
 func TestNamespace(t *testing.T) {
 	require.Equal(t, "space_test", normalizeName(createGauge("test", ""), "space"))
 	require.Equal(t, "space_test", normalizeName(createGauge("#test", ""), "space"))

receiver/prometheusreceiver/README.md

@@ -102,6 +102,28 @@ receivers:
               action: keep
 ```
 
+The prometheus receiver also supports additional top-level options:
+
+- **trim_metric_suffixes**: [**Experimental**] When set to true, this enables trimming unit and some counter type suffixes from metric names. For example, it would cause `singing_duration_seconds_total` to be trimmed to `singing_duration`. This can be useful when trying to restore the original metric names used in OpenTelemetry instrumentation. Defaults to false.
+- **use_start_time_metric**: When set to true, this enables retrieving the start time of all counter metrics from the process_start_time_seconds metric. This is only correct if all counters on that endpoint started after the process start time, and the process is the only actor exporting the metric after the process started. It should not be used in "exporters" which export counters that may have started before the process itself. Use only if you know what you are doing, as this may result in incorrect rate calculations. Defaults to false.
+- **start_time_metric_regex**: The regular expression for the start time metric, and is only applied when use_start_time_metric is enabled.  Defaults to process_start_time_seconds.
+
+For example,
+
+```yaml
+receivers:
+    prometheus:
+      trim_metric_suffixes: true
+      use_start_time_metric: true
+      start_time_metric_regex: foo_bar_.*
+      config:
+        scrape_configs:
+          - job_name: 'otel-collector'
+            scrape_interval: 5s
+            static_configs:
+              - targets: ['0.0.0.0:8888']
+```
+
 ## OpenTelemetry Operator 
 Additional to this static job definitions this receiver allows to query a list of jobs from the 
 OpenTelemetryOperators TargetAllocator or a compatible endpoint. 

receiver/prometheusreceiver/config.go

@@ -32,9 +32,10 @@ const (
 
 // Config defines configuration for Prometheus receiver.
 type Config struct {
-	PrometheusConfig *promconfig.Config `mapstructure:"-"`
-	BufferPeriod     time.Duration      `mapstructure:"buffer_period"`
-	BufferCount      int                `mapstructure:"buffer_count"`
+	PrometheusConfig   *promconfig.Config `mapstructure:"-"`
+	TrimMetricSuffixes bool               `mapstructure:"trim_metric_suffixes"`
+	BufferPeriod       time.Duration      `mapstructure:"buffer_period"`
+	BufferCount        int                `mapstructure:"buffer_count"`
 	// UseStartTimeMetric enables retrieving the start time of all counter metrics
 	// from the process_start_time_seconds metric. This is only correct if all counters on that endpoint
 	// started after the process start time, and the process is the only actor exporting the metric after

receiver/prometheusreceiver/config_test.go

@@ -40,6 +40,7 @@ func TestLoadConfig(t *testing.T) {
 	assert.Equal(t, r1.PrometheusConfig.ScrapeConfigs[0].JobName, "demo")
 	assert.Equal(t, time.Duration(r1.PrometheusConfig.ScrapeConfigs[0].ScrapeInterval), 5*time.Second)
 	assert.Equal(t, r1.UseStartTimeMetric, true)
+	assert.Equal(t, r1.TrimMetricSuffixes, true)
 	assert.Equal(t, r1.StartTimeMetricRegex, "^(.+_)*process_start_time_seconds$")
 
 	assert.Equal(t, "http://my-targetallocator-service", r1.TargetAllocator.Endpoint)

receiver/prometheusreceiver/factory.go

@@ -49,5 +49,5 @@ func createMetricsReceiver(
 	cfg component.Config,
 	nextConsumer consumer.Metrics,
 ) (receiver.Metrics, error) {
-	return newPrometheusReceiver(set, cfg.(*Config), nextConsumer, featuregate.GlobalRegistry()), nil
+	return newPrometheusReceiver(set, cfg.(*Config), nextConsumer), nil
 }

receiver/prometheusreceiver/internal/appendable.go

@@ -11,7 +11,6 @@ import (
 	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/storage"
 	"go.opentelemetry.io/collector/consumer"
-	"go.opentelemetry.io/collector/featuregate"
 	"go.opentelemetry.io/collector/obsreport"
 	"go.opentelemetry.io/collector/receiver"
 )
@@ -21,12 +20,12 @@ type appendable struct {
 	sink                 consumer.Metrics
 	metricAdjuster       MetricsAdjuster
 	useStartTimeMetric   bool
+	trimSuffixes         bool
 	startTimeMetricRegex *regexp.Regexp
 	externalLabels       labels.Labels
 
 	settings receiver.CreateSettings
 	obsrecv  *obsreport.Receiver
-	registry *featuregate.Registry
 }
 
 // NewAppendable returns a storage.Appendable instance that emits metrics to the sink.
@@ -38,7 +37,7 @@ func NewAppendable(
 	startTimeMetricRegex *regexp.Regexp,
 	useCreatedMetric bool,
 	externalLabels labels.Labels,
-	registry *featuregate.Registry) (storage.Appendable, error) {
+	trimSuffixes bool) (storage.Appendable, error) {
 	var metricAdjuster MetricsAdjuster
 	if !useStartTimeMetric {
 		metricAdjuster = NewInitialPointAdjuster(set.Logger, gcInterval, useCreatedMetric)
@@ -59,10 +58,10 @@ func NewAppendable(
 		startTimeMetricRegex: startTimeMetricRegex,
 		externalLabels:       externalLabels,
 		obsrecv:              obsrecv,
-		registry:             registry,
+		trimSuffixes:         trimSuffixes,
 	}, nil
 }
 
 func (o *appendable) Appender(ctx context.Context) storage.Appender {
-	return newTransaction(ctx, o.metricAdjuster, o.sink, o.externalLabels, o.settings, o.obsrecv, o.registry)
+	return newTransaction(ctx, o.metricAdjuster, o.sink, o.externalLabels, o.settings, o.obsrecv, o.trimSuffixes)
 }

receiver/prometheusreceiver/internal/metricfamily.go

@@ -301,10 +301,14 @@ func (mf *metricFamily) addSeries(seriesRef uint64, metricName string, ls labels
 	return nil
 }
 
-func (mf *metricFamily) appendMetric(metrics pmetric.MetricSlice, normalizer *prometheus.Normalizer) {
+func (mf *metricFamily) appendMetric(metrics pmetric.MetricSlice, trimSuffixes bool) {
 	metric := pmetric.NewMetric()
-	// Trims type's and unit's suffixes from metric name
-	metric.SetName(normalizer.TrimPromSuffixes(mf.name, mf.mtype, mf.metadata.Unit))
+	// Trims type and unit suffixes from metric name
+	name := mf.name
+	if trimSuffixes {
+		name = prometheus.TrimPromSuffixes(name, mf.mtype, mf.metadata.Unit)
+	}
+	metric.SetName(name)
 	metric.SetDescription(mf.metadata.Help)
 	metric.SetUnit(mf.metadata.Unit)
 

receiver/prometheusreceiver/internal/metricfamily_test.go

@@ -13,12 +13,9 @@ import (
 	"github.com/prometheus/prometheus/model/value"
 	"github.com/prometheus/prometheus/scrape"
 	"github.com/stretchr/testify/require"
-	"go.opentelemetry.io/collector/featuregate"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/pmetric"
 	"go.uber.org/zap"
-
-	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/prometheus"
 )
 
 type testMetadataStore map[string]scrape.MetricMetadata
@@ -252,7 +249,7 @@ func TestMetricGroupData_toDistributionUnitTest(t *testing.T) {
 			require.Len(t, mp.groups, 1)
 
 			sl := pmetric.NewMetricSlice()
-			mp.appendMetric(sl, prometheus.NewNormalizer(featuregate.GlobalRegistry()))
+			mp.appendMetric(sl, false)
 
 			require.Equal(t, 1, sl.Len(), "Exactly one metric expected")
 			metric := sl.At(0)
@@ -540,7 +537,7 @@ func TestMetricGroupData_toSummaryUnitTest(t *testing.T) {
 			require.Len(t, mp.groups, 1)
 
 			sl := pmetric.NewMetricSlice()
-			mp.appendMetric(sl, prometheus.NewNormalizer(featuregate.GlobalRegistry()))
+			mp.appendMetric(sl, false)
 
 			require.Equal(t, 1, sl.Len(), "Exactly one metric expected")
 			metric := sl.At(0)
@@ -646,7 +643,7 @@ func TestMetricGroupData_toNumberDataUnitTest(t *testing.T) {
 			require.Len(t, mp.groups, 1)
 
 			sl := pmetric.NewMetricSlice()
-			mp.appendMetric(sl, prometheus.NewNormalizer(featuregate.GlobalRegistry()))
+			mp.appendMetric(sl, false)
 
 			require.Equal(t, 1, sl.Len(), "Exactly one metric expected")
 			metric := sl.At(0)