otlptranslator: Add tests for BuildCompliantName

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

storage/remote/otlptranslator/prometheus/normalize_label.go

@@ -21,15 +21,14 @@ import (
 	"unicode"
 )
 
-// Normalizes the specified label to follow Prometheus label names standard
+// Normalizes the specified label to follow Prometheus label names standard.
 //
-// See rules at https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels
+// See rules at https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels.
 //
-// Labels that start with non-letter rune will be prefixed with "key_"
+// Labels that start with non-letter rune will be prefixed with "key_".
 //
-// Exception is made for double-underscores which are allowed
+// An exception is made for double-underscores which are allowed.
 func NormalizeLabel(label string) string {
-
 	// Trivial case
 	if len(label) == 0 {
 		return label
@@ -48,7 +47,7 @@ func NormalizeLabel(label string) string {
 	return label
 }
 
-// Return '_' for anything non-alphanumeric
+// Return '_' for anything non-alphanumeric.
 func sanitizeRune(r rune) rune {
 	if unicode.IsLetter(r) || unicode.IsDigit(r) {
 		return r

storage/remote/otlptranslator/prometheus/normalize_name.go

@@ -76,14 +76,15 @@ var perUnitMap = map[string]string{
 	"y":  "year",
 }
 
-// BuildCompliantName builds a Prometheus-compliant metric name for the specified metric
+// BuildCompliantName builds a Prometheus-compliant metric name for the specified metric.
 //
 // Metric name is prefixed with specified namespace and underscore (if any).
 // Namespace is not cleaned up. Make sure specified namespace follows Prometheus
 // naming convention.
 //
-// See rules at https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels
+// See rules at https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels,
-// and https://prometheus.io/docs/practices/naming/#metric-and-label-naming
+// https://prometheus.io/docs/practices/naming/#metric-and-label-naming
+// and https://github.com/open-telemetry/opentelemetry-specification/blob/v1.33.0/specification/compatibility/prometheus_and_openmetrics.md#otlp-metric-points-to-prometheus.
 func BuildCompliantName(metric pmetric.Metric, namespace string, addMetricSuffixes bool) string {
 	var metricName string
 
@@ -110,7 +111,7 @@ func BuildCompliantName(metric pmetric.Metric, namespace string, addMetricSuffix
 
 // Build a normalized name for the specified metric
 func normalizeName(metric pmetric.Metric, namespace string) string {
-	// Split metric name in "tokens" (remove all non-alphanumeric)
+	// Split metric name into "tokens" (remove all non-alphanumerics)
 	nameTokens := strings.FieldsFunc(
 		metric.Name(),
 		func(r rune) bool { return !unicode.IsLetter(r) && !unicode.IsDigit(r) },
@@ -122,9 +123,9 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 	// Main unit
 	// Append if not blank, doesn't contain '{}', and is not present in metric name already
 	if len(unitTokens) > 0 {
-		mainUnitOtel := strings.TrimSpace(unitTokens[0])
+		mainUnitOTel := strings.TrimSpace(unitTokens[0])
-		if mainUnitOtel != "" && !strings.ContainsAny(mainUnitOtel, "{}") {
+		if mainUnitOTel != "" && !strings.ContainsAny(mainUnitOTel, "{}") {
-			mainUnitProm := CleanUpString(unitMapGetOrDefault(mainUnitOtel))
+			mainUnitProm := CleanUpString(unitMapGetOrDefault(mainUnitOTel))
 			if mainUnitProm != "" && !contains(nameTokens, mainUnitProm) {
 				nameTokens = append(nameTokens, mainUnitProm)
 			}
@@ -133,11 +134,11 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 		// Per unit
 		// Append if not blank, doesn't contain '{}', and is not present in metric name already
 		if len(unitTokens) > 1 && unitTokens[1] != "" {
-			perUnitOtel := strings.TrimSpace(unitTokens[1])
+			perUnitOTel := strings.TrimSpace(unitTokens[1])
-			if perUnitOtel != "" && !strings.ContainsAny(perUnitOtel, "{}") {
+			if perUnitOTel != "" && !strings.ContainsAny(perUnitOTel, "{}") {
-				perUnitProm := CleanUpString(perUnitMapGetOrDefault(perUnitOtel))
+				perUnitProm := CleanUpString(perUnitMapGetOrDefault(perUnitOTel))
 				if perUnitProm != "" && !contains(nameTokens, perUnitProm) {
-					nameTokens = append(append(nameTokens, "per"), perUnitProm)
+					nameTokens = append(nameTokens, "per", perUnitProm)
 				}
 			}
 		}
@@ -150,7 +151,7 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 	}
 
 	// Append _ratio for metrics with unit "1"
-	// Some Otel receivers improperly use unit "1" for counters of objects
+	// Some OTel receivers improperly use unit "1" for counters of objects
 	// See https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aissue+some+metric+units+don%27t+follow+otel+semantic+conventions
 	// Until these issues have been fixed, we're appending `_ratio` for gauges ONLY
 	// Theoretically, counters could be ratios as well, but it's absurd (for mathematical reasons)

storage/remote/otlptranslator/prometheus/normalize_name_test.go

@@ -0,0 +1,203 @@
+// 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/open-telemetry/opentelemetry-collector-contrib/blob/95e8f8fdc2a9dc87230406c9a3cf02be4fd68bea/pkg/translator/prometheus/normalize_name_test.go
+// Provenance-includes-license: Apache-2.0
+// Provenance-includes-copyright: Copyright The OpenTelemetry Authors.
+
+package prometheus
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+)
+
+func TestByte(t *testing.T) {
+	require.Equal(t, "system_filesystem_usage_bytes", normalizeName(createGauge("system.filesystem.usage", "By"), ""))
+}
+
+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"), ""))
+}
+
+func TestWhiteSpaces(t *testing.T) {
+	require.Equal(t, "system_filesystem_usage_bytes", normalizeName(createGauge("\t system.filesystem.usage       ", "  By\t"), ""))
+}
+
+func TestNonStandardUnit(t *testing.T) {
+	require.Equal(t, "system_network_dropped", normalizeName(createGauge("system.network.dropped", "{packets}"), ""))
+}
+
+func TestNonStandardUnitCounter(t *testing.T) {
+	require.Equal(t, "system_network_dropped_total", normalizeName(createCounter("system.network.dropped", "{packets}"), ""))
+}
+
+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"), ""))
+}
+
+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"), ""))
+}
+
+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"), ""))
+}
+
+func TestHertz(t *testing.T) {
+	require.Equal(t, "hw_cpu_speed_limit_hertz", normalizeName(createGauge("hw.cpu.speed_limit", "Hz"), ""))
+}
+
+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"), ""))
+}
+
+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", "%"), ""))
+}
+
+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  "), ""))
+}
+
+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 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"), ""))
+}
+
+func TestTrimPromSuffixes(t *testing.T) {
+	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", 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", 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 TestNamespace(t *testing.T) {
+	require.Equal(t, "space_test", normalizeName(createGauge("test", ""), "space"))
+	require.Equal(t, "space_test", normalizeName(createGauge("#test", ""), "space"))
+}
+
+func TestCleanUpString(t *testing.T) {
+	require.Equal(t, "", CleanUpString(""))
+	require.Equal(t, "a_b", CleanUpString("a b"))
+	require.Equal(t, "hello_world", CleanUpString("hello, world!"))
+	require.Equal(t, "hello_you_2", CleanUpString("hello you 2"))
+	require.Equal(t, "1000", CleanUpString("$1000"))
+	require.Equal(t, "", CleanUpString("*+$^=)"))
+}
+
+func TestUnitMapGetOrDefault(t *testing.T) {
+	require.Equal(t, "", unitMapGetOrDefault(""))
+	require.Equal(t, "seconds", unitMapGetOrDefault("s"))
+	require.Equal(t, "invalid", unitMapGetOrDefault("invalid"))
+}
+
+func TestPerUnitMapGetOrDefault(t *testing.T) {
+	require.Equal(t, "", perUnitMapGetOrDefault(""))
+	require.Equal(t, "second", perUnitMapGetOrDefault("s"))
+	require.Equal(t, "invalid", perUnitMapGetOrDefault("invalid"))
+}
+
+func TestRemoveItem(t *testing.T) {
+	require.Equal(t, []string{}, removeItem([]string{}, "test"))
+	require.Equal(t, []string{}, removeItem([]string{}, ""))
+	require.Equal(t, []string{"a", "b", "c"}, removeItem([]string{"a", "b", "c"}, "d"))
+	require.Equal(t, []string{"a", "b", "c"}, removeItem([]string{"a", "b", "c"}, ""))
+	require.Equal(t, []string{"a", "b"}, removeItem([]string{"a", "b", "c"}, "c"))
+	require.Equal(t, []string{"a", "c"}, removeItem([]string{"a", "b", "c"}, "b"))
+	require.Equal(t, []string{"b", "c"}, removeItem([]string{"a", "b", "c"}, "a"))
+}
+
+func TestBuildCompliantNameWithNormalize(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))
+	// Gauges with unit 1 are considered ratios.
+	require.Equal(t, "foo_bar_ratio", BuildCompliantName(createGauge("foo.bar", "1"), "", true))
+	// Slashes in units are converted.
+	require.Equal(t, "system_io_foo_per_bar_total", BuildCompliantName(createCounter("system.io", "foo/bar"), "", true))
+}
+
+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))
+}

storage/remote/otlptranslator/prometheus/testutils_test.go

@@ -0,0 +1,49 @@
+// 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/open-telemetry/opentelemetry-collector-contrib/blob/95e8f8fdc2a9dc87230406c9a3cf02be4fd68bea/pkg/translator/prometheus/testutils_test.go
+// Provenance-includes-license: Apache-2.0
+// Provenance-includes-copyright: Copyright The OpenTelemetry Authors.
+
+package prometheus
+
+import (
+	"go.opentelemetry.io/collector/pdata/pmetric"
+)
+
+var ilm pmetric.ScopeMetrics
+
+func init() {
+
+	metrics := pmetric.NewMetrics()
+	resourceMetrics := metrics.ResourceMetrics().AppendEmpty()
+	ilm = resourceMetrics.ScopeMetrics().AppendEmpty()
+
+}
+
+// Returns a new Metric of type "Gauge" with specified name and unit
+func createGauge(name string, unit string) pmetric.Metric {
+	gauge := ilm.Metrics().AppendEmpty()
+	gauge.SetName(name)
+	gauge.SetUnit(unit)
+	gauge.SetEmptyGauge()
+	return gauge
+}
+
+// Returns a new Metric of type Monotonic Sum with specified name and unit
+func createCounter(name string, unit string) pmetric.Metric {
+	counter := ilm.Metrics().AppendEmpty()
+	counter.SetEmptySum().SetIsMonotonic(true)
+	counter.SetName(name)
+	counter.SetUnit(unit)
+	return counter
+}