From dfefb44dcd6f5cc4052c247ccedceaf3b8ca0a33 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sat, 9 Sep 2023 00:25:50 +0800
Subject: [PATCH 01/25] Export resource for prometheus

---
 .../exporters/prometheus/exporter_utils.h     |  27 +++-
 exporters/prometheus/src/exporter_utils.cc    | 122 +++++++++++++++---
 .../prometheus/test/exporter_utils_test.cc    |  65 +++++++++-
 3 files changed, 191 insertions(+), 23 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index ce7f0a1191..c6eea5265d 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -41,6 +41,24 @@ class PrometheusExporterUtils
    */
   static std::string SanitizeNames(std::string name);
 
+  /**
+   * Some attributes should be ignored when converting resource attributes to
+   * prometheus labels.
+   *
+   * @param name resource attribnuet name
+   * @return true if the attribute should be ignored, false otherwise.
+   */
+  static bool ShouldIgnoreResourceAttribute(const std::string &name);
+
+  /**
+   * Some attributes should be renamed when converting resource attributes to
+   * prometheus labels.
+   *
+   * @param name resource attribnuet name
+   * @return const std::string&
+   */
+  static const std::string &GetPrometheusAttributeName(const std::string &name);
+
   static opentelemetry::sdk::metrics::AggregationType getAggregationType(
       const opentelemetry::sdk::metrics::PointType &point_type);
 
@@ -59,7 +77,8 @@ class PrometheusExporterUtils
                       const opentelemetry::sdk::metrics::PointAttributes &labels,
                       ::prometheus::MetricType type,
                       std::chrono::nanoseconds time,
-                      ::prometheus::MetricFamily *metric_family);
+                      ::prometheus::MetricFamily *metric_family,
+                      const opentelemetry::sdk::resource::Resource *resource);
 
   /**
    * Set metric data for:
@@ -71,14 +90,16 @@ class PrometheusExporterUtils
                       const std::vector<uint64_t> &counts,
                       const opentelemetry::sdk::metrics::PointAttributes &labels,
                       std::chrono::nanoseconds time,
-                      ::prometheus::MetricFamily *metric_family);
+                      ::prometheus::MetricFamily *metric_family,
+                      const opentelemetry::sdk::resource::Resource *resource);
 
   /**
    * Set time and labels to metric data
    */
   static void SetMetricBasic(::prometheus::ClientMetric &metric,
                              std::chrono::nanoseconds time,
-                             const opentelemetry::sdk::metrics::PointAttributes &labels);
+                             const opentelemetry::sdk::metrics::PointAttributes &labels,
+                             const opentelemetry::sdk::resource::Resource *resource);
 
   /**
    * Convert attribute value to string
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 966d665df6..fe61250bec 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -2,13 +2,19 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include <sstream>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
 #include <utility>
 #include <vector>
+#include "opentelemetry/sdk/resource/resource.h"
 #include "prometheus/metric_family.h"
 
 #include <prometheus/metric_type.h>
 #include "opentelemetry/exporters/prometheus/exporter_utils.h"
 #include "opentelemetry/sdk/metrics/export/metric_producer.h"
+#include "opentelemetry/sdk/resource/semantic_conventions.h"
+#include "opentelemetry/trace/semantic_conventions.h"
 
 #include "opentelemetry/sdk/common/global_log_handler.h"
 
@@ -20,6 +26,7 @@ namespace exporter
 {
 namespace metrics
 {
+
 /**
  * Helper function to convert OpenTelemetry metrics data collection
  * to Prometheus metrics data collection
@@ -72,7 +79,7 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
             sum = nostd::get<int64_t>(histogram_point_data.sum_);
           }
           SetData(std::vector<double>{sum, (double)histogram_point_data.count_}, boundaries, counts,
-                  point_data_attr.attributes, time, &metric_family);
+                  point_data_attr.attributes, time, &metric_family, data.resource_);
         }
         else if (type == prometheus_client::MetricType::Gauge)
         {
@@ -82,14 +89,14 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
             auto last_value_point_data =
                 nostd::get<sdk::metrics::LastValuePointData>(point_data_attr.point_data);
             std::vector<metric_sdk::ValueType> values{last_value_point_data.value_};
-            SetData(values, point_data_attr.attributes, type, time, &metric_family);
+            SetData(values, point_data_attr.attributes, type, time, &metric_family, data.resource_);
           }
           else if (nostd::holds_alternative<sdk::metrics::SumPointData>(point_data_attr.point_data))
           {
             auto sum_point_data =
                 nostd::get<sdk::metrics::SumPointData>(point_data_attr.point_data);
             std::vector<metric_sdk::ValueType> values{sum_point_data.value_};
-            SetData(values, point_data_attr.attributes, type, time, &metric_family);
+            SetData(values, point_data_attr.attributes, type, time, &metric_family, data.resource_);
           }
           else
           {
@@ -105,7 +112,7 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
             auto sum_point_data =
                 nostd::get<sdk::metrics::SumPointData>(point_data_attr.point_data);
             std::vector<metric_sdk::ValueType> values{sum_point_data.value_};
-            SetData(values, point_data_attr.attributes, type, time, &metric_family);
+            SetData(values, point_data_attr.attributes, type, time, &metric_family, data.resource_);
           }
           else
           {
@@ -167,6 +174,30 @@ std::string PrometheusExporterUtils::SanitizeNames(std::string name)
   return name;
 }
 
+bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &name)
+{
+  static std::unordered_set<std::string> ignores{
+      opentelemetry::sdk::resource::SemanticConventions::kServiceName,
+      opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace,
+      opentelemetry::trace::SemanticConventions::kServerAddress,
+      opentelemetry::trace::SemanticConventions::kServerPort,
+      opentelemetry::trace::SemanticConventions::kUrlScheme};
+  return ignores.end() == ignores.find(name);
+}
+
+const std::string &PrometheusExporterUtils::GetPrometheusAttributeName(const std::string &name)
+{
+  static std::unordered_map<std::string, std::string> name_mappings{
+      {opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId, "instance"}};
+  std::unordered_map<std::string, std::string>::const_iterator it = name_mappings.find(name);
+  if (it == name_mappings.end())
+  {
+    return name;
+  }
+
+  return it->second;
+}
+
 metric_sdk::AggregationType PrometheusExporterUtils::getAggregationType(
     const metric_sdk::PointType &point_type)
 {
@@ -229,11 +260,12 @@ void PrometheusExporterUtils::SetData(std::vector<T> values,
                                       const metric_sdk::PointAttributes &labels,
                                       prometheus_client::MetricType type,
                                       std::chrono::nanoseconds time,
-                                      prometheus_client::MetricFamily *metric_family)
+                                      prometheus_client::MetricFamily *metric_family,
+                                      const opentelemetry::sdk::resource::Resource *resource)
 {
   metric_family->metric.emplace_back();
   prometheus_client::ClientMetric &metric = metric_family->metric.back();
-  SetMetricBasic(metric, time, labels);
+  SetMetricBasic(metric, time, labels, resource);
   SetValue(values, type, &metric);
 }
 
@@ -247,11 +279,12 @@ void PrometheusExporterUtils::SetData(std::vector<T> values,
                                       const std::vector<uint64_t> &counts,
                                       const metric_sdk::PointAttributes &labels,
                                       std::chrono::nanoseconds time,
-                                      prometheus_client::MetricFamily *metric_family)
+                                      prometheus_client::MetricFamily *metric_family,
+                                      const opentelemetry::sdk::resource::Resource *resource)
 {
   metric_family->metric.emplace_back();
   prometheus_client::ClientMetric &metric = metric_family->metric.back();
-  SetMetricBasic(metric, time, labels);
+  SetMetricBasic(metric, time, labels, resource);
   SetValue(values, boundaries, counts, &metric);
 }
 
@@ -260,20 +293,79 @@ void PrometheusExporterUtils::SetData(std::vector<T> values,
  */
 void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &metric,
                                              std::chrono::nanoseconds time,
-                                             const metric_sdk::PointAttributes &labels)
+                                             const metric_sdk::PointAttributes &labels,
+                                             const opentelemetry::sdk::resource::Resource *resource)
 {
   metric.timestamp_ms = time.count() / 1000000;
 
+  std::size_t label_size = 0;
+  if (nullptr != resource)
+  {
+    label_size += resource->GetAttributes().size();
+  }
+  if (!labels.empty())
+  {
+    label_size += labels.size();
+  }
+  metric.label.resize(label_size);
+
+  // Convert resource to prometheus labels
+  if (nullptr != resource)
+  {
+    opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
+        resource->GetAttributes().find(
+            opentelemetry::sdk::resource::SemanticConventions::kServiceName);
+    opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_namespace_it =
+        resource->GetAttributes().find(
+            opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace);
+
+    if (service_namespace_it != resource->GetAttributes().end() &&
+        service_name_it != resource->GetAttributes().end())
+    {
+      prometheus_client::ClientMetric::Label prometheus_label;
+      prometheus_label.name  = "job";
+      prometheus_label.value = AttributeValueToString(service_namespace_it->second) + "/" +
+                               AttributeValueToString(service_name_it->second);
+      metric.label.emplace_back(std::move(prometheus_label));
+    }
+    else if (service_name_it != resource->GetAttributes().end())
+    {
+      prometheus_client::ClientMetric::Label prometheus_label;
+      prometheus_label.name  = "job";
+      prometheus_label.value = AttributeValueToString(service_name_it->second);
+      metric.label.emplace_back(std::move(prometheus_label));
+    }
+    else if (service_namespace_it != resource->GetAttributes().end())
+    {
+      prometheus_client::ClientMetric::Label prometheus_label;
+      prometheus_label.name  = "job";
+      prometheus_label.value = AttributeValueToString(service_namespace_it->second);
+      metric.label.emplace_back(std::move(prometheus_label));
+    }
+
+    for (auto &label : resource->GetAttributes())
+    {
+      if (ShouldIgnoreResourceAttribute(label.first))
+      {
+        continue;
+      }
+
+      prometheus_client::ClientMetric::Label prometheus_label;
+      prometheus_label.name  = SanitizeNames(GetPrometheusAttributeName(label.first));
+      prometheus_label.value = AttributeValueToString(label.second);
+      metric.label.emplace_back(std::move(prometheus_label));
+    }
+  }
+
   // auto label_pairs = ParseLabel(labels);
   if (!labels.empty())
   {
-    metric.label.resize(labels.size());
-    size_t i = 0;
-    for (auto const &label : labels)
+    for (auto &label : labels)
     {
-      auto sanitized          = SanitizeNames(label.first);
-      metric.label[i].name    = sanitized;
-      metric.label[i++].value = AttributeValueToString(label.second);
+      prometheus_client::ClientMetric::Label prometheus_label;
+      prometheus_label.name  = SanitizeNames(label.first);
+      prometheus_label.value = AttributeValueToString(label.second);
+      metric.label.emplace_back(std::move(prometheus_label));
     }
   }
 }
diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index 2eac7a6d8b..6e852fe6b8 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -6,6 +6,7 @@
 #include "prometheus/metric_type.h"
 
 #include "opentelemetry/exporters/prometheus/exporter_utils.h"
+#include "opentelemetry/sdk/resource/resource.h"
 #include "prometheus_test_helper.h"
 
 using opentelemetry::exporter::metrics::PrometheusExporterUtils;
@@ -35,7 +36,7 @@ void assert_basic(prometheus_client::MetricFamily &metric,
                   const std::string &sanitized_name,
                   const std::string &description,
                   prometheus_client::MetricType type,
-                  int label_num,
+                  size_t label_num,
                   std::vector<T> vals)
 {
   ASSERT_EQ(metric.name, sanitized_name + "_unit");  // name sanitized
@@ -107,28 +108,82 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusEmptyInputReturnsEmptyCollect
 TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerCounter)
 {
 
+  opentelemetry::sdk::resource::Resource resource = opentelemetry::sdk::resource::Resource::Create(
+      {{"service.name", "test_service"},
+       {"service.namespace", "test_namespace"},
+       {"service.instance.id", "localhost:8000"},
+       {"custom_resource_attr", "custom_resource_value"}});
   metric_sdk::ResourceMetrics metrics_data = CreateSumPointData();
+  metrics_data.resource_                   = &resource;
 
   auto translated = PrometheusExporterUtils::TranslateToPrometheus(metrics_data);
   ASSERT_EQ(translated.size(), 1);
 
   auto metric1          = translated[0];
   std::vector<int> vals = {10};
-  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter, 1,
-               vals);
+
+  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter,
+               resource.GetAttributes().size(), vals);
+
+  int checked_label_num = 0;
+  for (auto &label : metric1.metric[0].label)
+  {
+    if (label.name == "job")
+    {
+      ASSERT_EQ(label.value, "test_namespace/test_service");
+      checked_label_num++;
+    }
+    else if (label.name == "instance")
+    {
+      ASSERT_EQ(label.value, "localhost:8000");
+      checked_label_num++;
+    }
+    else if (label.name == "custom_resource_attr")
+    {
+      ASSERT_EQ(label.value, "custom_resource_value");
+      checked_label_num++;
+    }
+  }
+  ASSERT_EQ(checked_label_num, 3);
 }
 
 TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerLastValue)
 {
+  opentelemetry::sdk::resource::Resource resource = opentelemetry::sdk::resource::Resource::Create(
+      {{"service.name", "test_service"},
+       {"service.instance.id", "localhost:8000"},
+       {"custom_resource_attr", "custom_resource_value"}});
   metric_sdk::ResourceMetrics metrics_data = CreateLastValuePointData();
+  metrics_data.resource_                   = &resource;
 
   auto translated = PrometheusExporterUtils::TranslateToPrometheus(metrics_data);
   ASSERT_EQ(translated.size(), 1);
 
   auto metric1          = translated[0];
   std::vector<int> vals = {10};
-  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Gauge, 1,
-               vals);
+  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Gauge,
+               resource.GetAttributes().size() + 1, vals);
+
+  int checked_label_num = 0;
+  for (auto &label : metric1.metric[0].label)
+  {
+    if (label.name == "job")
+    {
+      ASSERT_EQ(label.value, "test_service");
+      checked_label_num++;
+    }
+    else if (label.name == "instance")
+    {
+      ASSERT_EQ(label.value, "localhost:8000");
+      checked_label_num++;
+    }
+    else if (label.name == "custom_resource_attr")
+    {
+      ASSERT_EQ(label.value, "custom_resource_value");
+      checked_label_num++;
+    }
+  }
+  ASSERT_EQ(checked_label_num, 3);
 }
 
 TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)

From ca3286ac7a0fb6ec189cfc7d0ac72d2aaebd2e55 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sat, 9 Sep 2023 17:37:19 +0800
Subject: [PATCH 02/25] Fix unit test in prometheus, fix resouce exporting for
 prometheus exporter

---
 CHANGELOG.md                                              | 2 ++
 exporters/prometheus/src/exporter_utils.cc                | 4 ++--
 exporters/prometheus/test/exporter_utils_test.cc          | 4 ++--
 exporters/prometheus/test/prometheus_test_helper.h        | 6 +++---
 .../opentelemetry/sdk/metrics/export/metric_producer.h    | 8 ++++++--
 5 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f09553ce70..a5dbff8cda 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,8 @@ Increment the:
 
 * [DEPRECATION] Deprecate ZPAGES
   [#2291](https://github.com/open-telemetry/opentelemetry-cpp/pull/2291)
+* [EXPORTER] Prometheus exporter emit resource attributes
+  [#2301](https://github.com/open-telemetry/opentelemetry-cpp/pull/2301)
 
 ## [1.11.0] 2023-08-21
 
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index fe61250bec..14a69d053d 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -182,7 +182,7 @@ bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &n
       opentelemetry::trace::SemanticConventions::kServerAddress,
       opentelemetry::trace::SemanticConventions::kServerPort,
       opentelemetry::trace::SemanticConventions::kUrlScheme};
-  return ignores.end() == ignores.find(name);
+  return ignores.end() != ignores.find(name);
 }
 
 const std::string &PrometheusExporterUtils::GetPrometheusAttributeName(const std::string &name)
@@ -307,7 +307,7 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   {
     label_size += labels.size();
   }
-  metric.label.resize(label_size);
+  metric.label.reserve(label_size);
 
   // Convert resource to prometheus labels
   if (nullptr != resource)
diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index 6e852fe6b8..a2591b103d 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -195,8 +195,8 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)
 
   auto metric              = translated[0];
   std::vector<double> vals = {3, 900.5, 4};
-  assert_basic(metric, "library_name", "description", prometheus_client::MetricType::Histogram, 1,
-               vals);
+  assert_basic(metric, "library_name", "description", prometheus_client::MetricType::Histogram,
+               metrics_data.resource_->GetAttributes().size() + 1, vals);
   assert_histogram(metric, std::list<double>{10.1, 20.2, 30.2}, {200, 300, 400, 500});
 }
 
diff --git a/exporters/prometheus/test/prometheus_test_helper.h b/exporters/prometheus/test/prometheus_test_helper.h
index 4743e032bd..8fc7a3cb3b 100644
--- a/exporters/prometheus/test/prometheus_test_helper.h
+++ b/exporters/prometheus/test/prometheus_test_helper.h
@@ -54,7 +54,7 @@ inline metric_sdk::ResourceMetrics CreateHistogramPointData()
   histogram_point_data2.counts_     = {200, 300, 400, 500};
   histogram_point_data2.sum_        = (int64_t)900;
   metric_sdk::ResourceMetrics data;
-  auto resource = opentelemetry::sdk::resource::Resource::Create(
+  static auto resource = opentelemetry::sdk::resource::Resource::Create(
       opentelemetry::sdk::resource::ResourceAttributes{});
   data.resource_ = &resource;
   auto instrumentation_scope =
@@ -77,7 +77,7 @@ inline metric_sdk::ResourceMetrics CreateHistogramPointData()
 inline metric_sdk::ResourceMetrics CreateLastValuePointData()
 {
   metric_sdk::ResourceMetrics data;
-  auto resource = opentelemetry::sdk::resource::Resource::Create(
+  static auto resource = opentelemetry::sdk::resource::Resource::Create(
       opentelemetry::sdk::resource::ResourceAttributes{});
   data.resource_ = &resource;
   auto instrumentation_scope =
@@ -108,7 +108,7 @@ inline metric_sdk::ResourceMetrics CreateLastValuePointData()
 inline metric_sdk::ResourceMetrics CreateDropPointData()
 {
   metric_sdk::ResourceMetrics data;
-  auto resource = opentelemetry::sdk::resource::Resource::Create(
+  static auto resource = opentelemetry::sdk::resource::Resource::Create(
       opentelemetry::sdk::resource::ResourceAttributes{});
   data.resource_ = &resource;
   auto instrumentation_scope =
diff --git a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
index 2a0c87fcaa..e70eaebce2 100644
--- a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
+++ b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
@@ -31,14 +31,18 @@ namespace metrics
  */
 struct ScopeMetrics
 {
-  const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope_;
+  const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope_ = nullptr;
   std::vector<MetricData> metric_data_;
+
+  ScopeMetrics() = default;
 };
 
 struct ResourceMetrics
 {
-  const opentelemetry::sdk::resource::Resource *resource_;
+  const opentelemetry::sdk::resource::Resource *resource_ = nullptr;
   std::vector<ScopeMetrics> scope_metric_data_;
+
+  ResourceMetrics() = default;
 };
 
 /**

From 14363681abc82efe0c4bb996c38a7061dece349c Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sat, 9 Sep 2023 19:28:18 +0800
Subject: [PATCH 03/25] Fix constructor

---
 .../sdk/metrics/export/metric_producer.h             | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
index e70eaebce2..b54ba9ebe1 100644
--- a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
+++ b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
@@ -34,7 +34,11 @@ struct ScopeMetrics
   const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope_ = nullptr;
   std::vector<MetricData> metric_data_;
 
-  ScopeMetrics() = default;
+  ScopeMetrics()                                = default;
+  ScopeMetrics(const ScopeMetrics &)            = default;
+  ScopeMetrics(ScopeMetrics &&)                 = default;
+  ScopeMetrics &operator=(const ScopeMetrics &) = default;
+  ScopeMetrics &operator=(ScopeMetrics &&)      = default;
 };
 
 struct ResourceMetrics
@@ -42,7 +46,11 @@ struct ResourceMetrics
   const opentelemetry::sdk::resource::Resource *resource_ = nullptr;
   std::vector<ScopeMetrics> scope_metric_data_;
 
-  ResourceMetrics() = default;
+  ResourceMetrics()                                   = default;
+  ResourceMetrics(const ResourceMetrics &)            = default;
+  ResourceMetrics(ResourceMetrics &&)                 = default;
+  ResourceMetrics &operator=(const ResourceMetrics &) = default;
+  ResourceMetrics &operator=(ResourceMetrics &&)      = default;
 };
 
 /**

From 22b8c94878118903b841d584adddf23785eab220 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sat, 9 Sep 2023 21:25:12 +0800
Subject: [PATCH 04/25] Fix compiling problem

---
 exporters/prometheus/src/exporter_utils.cc    |  5 +--
 .../sdk/metrics/export/metric_producer.h      | 33 +++++++++++++------
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 14a69d053d..41d0637a19 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -7,12 +7,13 @@
 #include <unordered_set>
 #include <utility>
 #include <vector>
-#include "opentelemetry/sdk/resource/resource.h"
+
 #include "prometheus/metric_family.h"
+#include "prometheus/metric_type.h"
 
-#include <prometheus/metric_type.h>
 #include "opentelemetry/exporters/prometheus/exporter_utils.h"
 #include "opentelemetry/sdk/metrics/export/metric_producer.h"
+#include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/resource/semantic_conventions.h"
 #include "opentelemetry/trace/semantic_conventions.h"
 
diff --git a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
index b54ba9ebe1..0d74d90400 100644
--- a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
+++ b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <utility>
 #include <vector>
 
 #include "opentelemetry/nostd/function_ref.h"
@@ -34,11 +35,17 @@ struct ScopeMetrics
   const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope_ = nullptr;
   std::vector<MetricData> metric_data_;
 
-  ScopeMetrics()                                = default;
-  ScopeMetrics(const ScopeMetrics &)            = default;
-  ScopeMetrics(ScopeMetrics &&)                 = default;
-  ScopeMetrics &operator=(const ScopeMetrics &) = default;
-  ScopeMetrics &operator=(ScopeMetrics &&)      = default;
+  template <class ScopePtr, class MetricDataType>
+  inline ScopeMetrics(ScopePtr &&scope, MetricDataType &&metric)
+      : scope_{std::move(scope)}, metric_data_{std::move(metric)}
+  {}
+
+  inline ScopeMetrics()                     = default;
+  inline ScopeMetrics(const ScopeMetrics &) = default;
+  inline ScopeMetrics(ScopeMetrics &&)      = default;
+
+  inline ScopeMetrics &operator=(const ScopeMetrics &) = default;
+  inline ScopeMetrics &operator=(ScopeMetrics &&)      = default;
 };
 
 struct ResourceMetrics
@@ -46,11 +53,17 @@ struct ResourceMetrics
   const opentelemetry::sdk::resource::Resource *resource_ = nullptr;
   std::vector<ScopeMetrics> scope_metric_data_;
 
-  ResourceMetrics()                                   = default;
-  ResourceMetrics(const ResourceMetrics &)            = default;
-  ResourceMetrics(ResourceMetrics &&)                 = default;
-  ResourceMetrics &operator=(const ResourceMetrics &) = default;
-  ResourceMetrics &operator=(ResourceMetrics &&)      = default;
+  template <class ResourcePtr, class ScopeMetricsType>
+  inline ResourceMetrics(ResourcePtr &&resource, ScopeMetricsType &&scope_metric_data)
+      : resource_{std::move(resource)}, scope_metric_data_{std::move(scope_metric_data)}
+  {}
+
+  inline ResourceMetrics()                        = default;
+  inline ResourceMetrics(const ResourceMetrics &) = default;
+  inline ResourceMetrics(ResourceMetrics &&)      = default;
+
+  inline ResourceMetrics &operator=(const ResourceMetrics &) = default;
+  inline ResourceMetrics &operator=(ResourceMetrics &&)      = default;
 };
 
 /**

From 3b15502e6ad0da66747dc102996cdd6b6cc5648b Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sat, 9 Sep 2023 22:00:15 +0800
Subject: [PATCH 05/25] Fix invalid resource pointer in unit test of prometheus

---
 .../prometheus/test/prometheus_test_helper.h  | 24 +++++++++----------
 .../sdk/metrics/export/metric_producer.h      |  6 +++--
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/exporters/prometheus/test/prometheus_test_helper.h b/exporters/prometheus/test/prometheus_test_helper.h
index 8fc7a3cb3b..b4b478ef25 100644
--- a/exporters/prometheus/test/prometheus_test_helper.h
+++ b/exporters/prometheus/test/prometheus_test_helper.h
@@ -11,6 +11,14 @@ namespace exportermetrics = opentelemetry::exporter::metrics;
 
 namespace
 {
+
+inline opentelemetry::sdk::resource::Resource &GetEmptyResource()
+{
+  static auto resource = opentelemetry::sdk::resource::Resource::Create(
+      opentelemetry::sdk::resource::ResourceAttributes{});
+  return resource;
+}
+
 /**
  * Helper function to create ResourceMetrics
  */
@@ -21,9 +29,7 @@ inline metric_sdk::ResourceMetrics CreateSumPointData()
   metric_sdk::SumPointData sum_point_data2{};
   sum_point_data2.value_ = 20.0;
   metric_sdk::ResourceMetrics data;
-  auto resource = opentelemetry::sdk::resource::Resource::Create(
-      opentelemetry::sdk::resource::ResourceAttributes{});
-  data.resource_ = &resource;
+  data.resource_ = &GetEmptyResource();
   auto instrumentation_scope =
       opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create("library_name",
                                                                              "1.2.0");
@@ -54,9 +60,7 @@ inline metric_sdk::ResourceMetrics CreateHistogramPointData()
   histogram_point_data2.counts_     = {200, 300, 400, 500};
   histogram_point_data2.sum_        = (int64_t)900;
   metric_sdk::ResourceMetrics data;
-  static auto resource = opentelemetry::sdk::resource::Resource::Create(
-      opentelemetry::sdk::resource::ResourceAttributes{});
-  data.resource_ = &resource;
+  data.resource_ = &GetEmptyResource();
   auto instrumentation_scope =
       opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create("library_name",
                                                                              "1.2.0");
@@ -77,9 +81,7 @@ inline metric_sdk::ResourceMetrics CreateHistogramPointData()
 inline metric_sdk::ResourceMetrics CreateLastValuePointData()
 {
   metric_sdk::ResourceMetrics data;
-  static auto resource = opentelemetry::sdk::resource::Resource::Create(
-      opentelemetry::sdk::resource::ResourceAttributes{});
-  data.resource_ = &resource;
+  data.resource_ = &GetEmptyResource();
   auto instrumentation_scope =
       opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create("library_name",
                                                                              "1.2.0");
@@ -108,9 +110,7 @@ inline metric_sdk::ResourceMetrics CreateLastValuePointData()
 inline metric_sdk::ResourceMetrics CreateDropPointData()
 {
   metric_sdk::ResourceMetrics data;
-  static auto resource = opentelemetry::sdk::resource::Resource::Create(
-      opentelemetry::sdk::resource::ResourceAttributes{});
-  data.resource_ = &resource;
+  data.resource_ = &GetEmptyResource();
   auto instrumentation_scope =
       opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create("library_name",
                                                                              "1.2.0");
diff --git a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
index 0d74d90400..2bef6f7a2c 100644
--- a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
+++ b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
@@ -45,7 +45,8 @@ struct ScopeMetrics
   inline ScopeMetrics(ScopeMetrics &&)      = default;
 
   inline ScopeMetrics &operator=(const ScopeMetrics &) = default;
-  inline ScopeMetrics &operator=(ScopeMetrics &&)      = default;
+
+  inline ScopeMetrics &operator=(ScopeMetrics &&) = default;
 };
 
 struct ResourceMetrics
@@ -63,7 +64,8 @@ struct ResourceMetrics
   inline ResourceMetrics(ResourceMetrics &&)      = default;
 
   inline ResourceMetrics &operator=(const ResourceMetrics &) = default;
-  inline ResourceMetrics &operator=(ResourceMetrics &&)      = default;
+
+  inline ResourceMetrics &operator=(ResourceMetrics &&) = default;
 };
 
 /**

From 1ffba54775c767f990399cd046f6993853d4f83e Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Tue, 12 Sep 2023 16:00:26 +0800
Subject: [PATCH 06/25] Fix "default member initializer" problem

---
 .../opentelemetry/sdk/metrics/export/metric_producer.h        | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
index 2bef6f7a2c..4bd5b131fb 100644
--- a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
+++ b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
@@ -40,7 +40,7 @@ struct ScopeMetrics
       : scope_{std::move(scope)}, metric_data_{std::move(metric)}
   {}
 
-  inline ScopeMetrics()                     = default;
+  inline ScopeMetrics() {}
   inline ScopeMetrics(const ScopeMetrics &) = default;
   inline ScopeMetrics(ScopeMetrics &&)      = default;
 
@@ -59,7 +59,7 @@ struct ResourceMetrics
       : resource_{std::move(resource)}, scope_metric_data_{std::move(scope_metric_data)}
   {}
 
-  inline ResourceMetrics()                        = default;
+  inline ResourceMetrics() {}
   inline ResourceMetrics(const ResourceMetrics &) = default;
   inline ResourceMetrics(ResourceMetrics &&)      = default;
 

From d2e144a1e6bee173d80aba6b3e0b30cc5d37577b Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 14 Sep 2023 17:37:00 +0800
Subject: [PATCH 07/25] Add `target_info` metric.

---
 .../exporters/prometheus/exporter_utils.h     |  23 +++-
 exporters/prometheus/src/exporter_utils.cc    | 125 ++++++++++++++----
 2 files changed, 118 insertions(+), 30 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index c6eea5265d..b7024aa701 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -41,11 +41,24 @@ class PrometheusExporterUtils
    */
   static std::string SanitizeNames(std::string name);
 
+  /**
+   * Append key-value pair to prometheus labels.
+   *
+   * @param name label name
+   * @param value label value
+   * @param labels target labels
+   *
+   * @return true if the attribute should be ignored, false otherwise.
+   */
+  static void AddPrometheusLabel(std::string name,
+                                 std::string value,
+                                 std::vector<::prometheus::ClientMetric::Label> *labels);
+
   /**
    * Some attributes should be ignored when converting resource attributes to
    * prometheus labels.
    *
-   * @param name resource attribnuet name
+   * @param name resource attribute name
    * @return true if the attribute should be ignored, false otherwise.
    */
   static bool ShouldIgnoreResourceAttribute(const std::string &name);
@@ -54,7 +67,7 @@ class PrometheusExporterUtils
    * Some attributes should be renamed when converting resource attributes to
    * prometheus labels.
    *
-   * @param name resource attribnuet name
+   * @param name resource attribute name
    * @return const std::string&
    */
   static const std::string &GetPrometheusAttributeName(const std::string &name);
@@ -68,6 +81,12 @@ class PrometheusExporterUtils
   static ::prometheus::MetricType TranslateType(opentelemetry::sdk::metrics::AggregationType kind,
                                                 bool is_monotonic = true);
 
+  /**
+   * Add a target_info metric to collect resource attributes
+   */
+  static void SetTarget(const sdk::metrics::ResourceMetrics &data,
+                        std::vector<::prometheus::MetricFamily> *output);
+
   /**
    * Set metric data for:
    * Counter => Prometheus Counter
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 41d0637a19..b09410d31e 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -28,6 +28,8 @@ namespace exporter
 namespace metrics
 {
 
+static constexpr const char *kPrometheusInstance = "instance";
+
 /**
  * Helper function to convert OpenTelemetry metrics data collection
  * to Prometheus metrics data collection
@@ -40,7 +42,17 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
 {
 
   // initialize output vector
+  std::size_t reserve_size = 1;
+  for (const auto &instrumentation_info : data.scope_metric_data_)
+  {
+    reserve_size += instrumentation_info.metric_data_.size();
+  }
+
   std::vector<prometheus_client::MetricFamily> output;
+  output.reserve(reserve_size);
+
+  // Append target_info as the first metric
+  SetTarget(data, &output);
 
   for (const auto &instrumentation_info : data.scope_metric_data_)
   {
@@ -175,6 +187,17 @@ std::string PrometheusExporterUtils::SanitizeNames(std::string name)
   return name;
 }
 
+void PrometheusExporterUtils::AddPrometheusLabel(
+    std::string name,
+    std::string value,
+    std::vector<::prometheus::ClientMetric::Label> *labels)
+{
+  prometheus_client::ClientMetric::Label prometheus_label;
+  prometheus_label.name  = std::move(name);
+  prometheus_label.value = std::move(value);
+  labels->emplace_back(std::move(prometheus_label));
+}
+
 bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &name)
 {
   static std::unordered_set<std::string> ignores{
@@ -189,7 +212,7 @@ bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &n
 const std::string &PrometheusExporterUtils::GetPrometheusAttributeName(const std::string &name)
 {
   static std::unordered_map<std::string, std::string> name_mappings{
-      {opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId, "instance"}};
+      {opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId, kPrometheusInstance}};
   std::unordered_map<std::string, std::string>::const_iterator it = name_mappings.find(name);
   if (it == name_mappings.end())
   {
@@ -252,6 +275,57 @@ prometheus_client::MetricType PrometheusExporterUtils::TranslateType(
   }
 }
 
+void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &data,
+                                        std::vector<::prometheus::MetricFamily> *output)
+{
+  if (output == nullptr || data.resource_ == nullptr)
+  {
+    return;
+  }
+  if (data.scope_metric_data_.empty())
+  {
+    return;
+  }
+  if ((*data.scope_metric_data_.begin()).metric_data_.empty())
+  {
+    return;
+  }
+
+  prometheus_client::MetricFamily metric_family;
+  metric_family.name = "target_info";
+  metric_family.help = "Target metadata";
+  metric_family.type = prometheus_client::MetricType::Info;
+  metric_family.metric.emplace_back();
+
+  prometheus_client::ClientMetric &metric = metric_family.metric.back();
+  metric.info.value                       = 1.0;
+
+  std::chrono::nanoseconds time;
+  for (const auto &instrumentation_info : data.scope_metric_data_)
+  {
+    for (const auto &metric_data : instrumentation_info.metric_data_)
+    {
+      time = metric_data.end_ts.time_since_epoch();
+      break;
+    }
+    break;
+  }
+
+  metric_sdk::PointAttributes empty_attributes;
+  SetMetricBasic(metric, time, empty_attributes, data.resource_);
+
+  for (auto &label : data.resource_->GetAttributes())
+  {
+    if (ShouldIgnoreResourceAttribute(label.first))
+    {
+      continue;
+    }
+
+    AddPrometheusLabel(SanitizeNames(GetPrometheusAttributeName(label.first)),
+                       AttributeValueToString(label.second), &metric.label);
+  }
+}
+
 /**
  * Set metric data for:
  * sum => Prometheus Counter
@@ -311,6 +385,7 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   metric.label.reserve(label_size);
 
   // Convert resource to prometheus labels
+  bool has_instance_label = false;
   if (nullptr != resource)
   {
     opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
@@ -323,51 +398,45 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
     if (service_namespace_it != resource->GetAttributes().end() &&
         service_name_it != resource->GetAttributes().end())
     {
-      prometheus_client::ClientMetric::Label prometheus_label;
-      prometheus_label.name  = "job";
-      prometheus_label.value = AttributeValueToString(service_namespace_it->second) + "/" +
-                               AttributeValueToString(service_name_it->second);
-      metric.label.emplace_back(std::move(prometheus_label));
+      AddPrometheusLabel("job",
+                         AttributeValueToString(service_namespace_it->second) + "/" +
+                             AttributeValueToString(service_name_it->second),
+                         &metric.label);
     }
     else if (service_name_it != resource->GetAttributes().end())
     {
-      prometheus_client::ClientMetric::Label prometheus_label;
-      prometheus_label.name  = "job";
-      prometheus_label.value = AttributeValueToString(service_name_it->second);
-      metric.label.emplace_back(std::move(prometheus_label));
+      AddPrometheusLabel("job", AttributeValueToString(service_name_it->second), &metric.label);
     }
     else if (service_namespace_it != resource->GetAttributes().end())
     {
-      prometheus_client::ClientMetric::Label prometheus_label;
-      prometheus_label.name  = "job";
-      prometheus_label.value = AttributeValueToString(service_namespace_it->second);
-      metric.label.emplace_back(std::move(prometheus_label));
+      AddPrometheusLabel("job", AttributeValueToString(service_namespace_it->second),
+                         &metric.label);
     }
+  }
 
-    for (auto &label : resource->GetAttributes())
+  // auto label_pairs = ParseLabel(labels);
+  if (!labels.empty())
+  {
+    for (auto &label : labels)
     {
       if (ShouldIgnoreResourceAttribute(label.first))
       {
         continue;
       }
 
-      prometheus_client::ClientMetric::Label prometheus_label;
-      prometheus_label.name  = SanitizeNames(GetPrometheusAttributeName(label.first));
-      prometheus_label.value = AttributeValueToString(label.second);
-      metric.label.emplace_back(std::move(prometheus_label));
+      std::string label_name = SanitizeNames(GetPrometheusAttributeName(label.first));
+      if (label_name == kPrometheusInstance)
+      {
+        has_instance_label = true;
+      }
+      AddPrometheusLabel(std::move(label_name), AttributeValueToString(label.second),
+                         &metric.label);
     }
   }
 
-  // auto label_pairs = ParseLabel(labels);
-  if (!labels.empty())
+  if (!has_instance_label)
   {
-    for (auto &label : labels)
-    {
-      prometheus_client::ClientMetric::Label prometheus_label;
-      prometheus_label.name  = SanitizeNames(label.first);
-      prometheus_label.value = AttributeValueToString(label.second);
-      metric.label.emplace_back(std::move(prometheus_label));
-    }
+    AddPrometheusLabel(kPrometheusInstance, "", &metric.label);
   }
 }
 

From 02f4d042c9e33e86b9a90bee7f5acafc315220ca Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 14 Sep 2023 20:14:01 +0800
Subject: [PATCH 08/25] Fix instance and job exporting

---
 .../exporters/prometheus/exporter_utils.h     |   9 --
 exporters/prometheus/src/exporter_utils.cc    | 129 +++++++++++-------
 exporters/prometheus/test/collector_test.cc   |   2 +-
 .../prometheus/test/exporter_utils_test.cc    |  98 +++++++++++--
 4 files changed, 169 insertions(+), 69 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index b7024aa701..67b1535968 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -63,15 +63,6 @@ class PrometheusExporterUtils
    */
   static bool ShouldIgnoreResourceAttribute(const std::string &name);
 
-  /**
-   * Some attributes should be renamed when converting resource attributes to
-   * prometheus labels.
-   *
-   * @param name resource attribute name
-   * @return const std::string&
-   */
-  static const std::string &GetPrometheusAttributeName(const std::string &name);
-
   static opentelemetry::sdk::metrics::AggregationType getAggregationType(
       const opentelemetry::sdk::metrics::PointType &point_type);
 
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index b09410d31e..0e76421a80 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -29,6 +29,7 @@ namespace metrics
 {
 
 static constexpr const char *kPrometheusInstance = "instance";
+static constexpr const char *kPrometheusJob      = "job";
 
 /**
  * Helper function to convert OpenTelemetry metrics data collection
@@ -205,23 +206,13 @@ bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &n
       opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace,
       opentelemetry::trace::SemanticConventions::kServerAddress,
       opentelemetry::trace::SemanticConventions::kServerPort,
-      opentelemetry::trace::SemanticConventions::kUrlScheme};
+      opentelemetry::trace::SemanticConventions::kUrlScheme,
+      opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId,
+      kPrometheusJob,
+      kPrometheusInstance};
   return ignores.end() != ignores.find(name);
 }
 
-const std::string &PrometheusExporterUtils::GetPrometheusAttributeName(const std::string &name)
-{
-  static std::unordered_map<std::string, std::string> name_mappings{
-      {opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId, kPrometheusInstance}};
-  std::unordered_map<std::string, std::string>::const_iterator it = name_mappings.find(name);
-  if (it == name_mappings.end())
-  {
-    return name;
-  }
-
-  return it->second;
-}
-
 metric_sdk::AggregationType PrometheusExporterUtils::getAggregationType(
     const metric_sdk::PointType &point_type)
 {
@@ -321,9 +312,11 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
       continue;
     }
 
-    AddPrometheusLabel(SanitizeNames(GetPrometheusAttributeName(label.first)),
-                       AttributeValueToString(label.second), &metric.label);
+    AddPrometheusLabel(SanitizeNames(label.first), AttributeValueToString(label.second),
+                       &metric.label);
   }
+
+  output->emplace_back(std::move(metric_family));
 }
 
 /**
@@ -384,37 +377,9 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   }
   metric.label.reserve(label_size);
 
-  // Convert resource to prometheus labels
-  bool has_instance_label = false;
-  if (nullptr != resource)
-  {
-    opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
-        resource->GetAttributes().find(
-            opentelemetry::sdk::resource::SemanticConventions::kServiceName);
-    opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_namespace_it =
-        resource->GetAttributes().find(
-            opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace);
-
-    if (service_namespace_it != resource->GetAttributes().end() &&
-        service_name_it != resource->GetAttributes().end())
-    {
-      AddPrometheusLabel("job",
-                         AttributeValueToString(service_namespace_it->second) + "/" +
-                             AttributeValueToString(service_name_it->second),
-                         &metric.label);
-    }
-    else if (service_name_it != resource->GetAttributes().end())
-    {
-      AddPrometheusLabel("job", AttributeValueToString(service_name_it->second), &metric.label);
-    }
-    else if (service_namespace_it != resource->GetAttributes().end())
-    {
-      AddPrometheusLabel("job", AttributeValueToString(service_namespace_it->second),
-                         &metric.label);
-    }
-  }
-
   // auto label_pairs = ParseLabel(labels);
+  bool has_instance_label = false;
+  bool has_job_label      = false;
   if (!labels.empty())
   {
     for (auto &label : labels)
@@ -424,16 +389,86 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
         continue;
       }
 
-      std::string label_name = SanitizeNames(GetPrometheusAttributeName(label.first));
+      std::string label_name = SanitizeNames(label.first);
       if (label_name == kPrometheusInstance)
       {
         has_instance_label = true;
       }
+      else if (label_name == kPrometheusJob)
+      {
+        has_job_label = true;
+      }
       AddPrometheusLabel(std::move(label_name), AttributeValueToString(label.second),
                          &metric.label);
     }
   }
 
+  // Convert resource to prometheus labels
+  if (nullptr != resource)
+  {
+    do
+    {
+      if (has_job_label)
+      {
+        break;
+      }
+
+      opentelemetry::sdk::resource::ResourceAttributes::const_iterator prometheus_job_it =
+          resource->GetAttributes().find(kPrometheusJob);
+      if (prometheus_job_it != resource->GetAttributes().end())
+      {
+        AddPrometheusLabel(kPrometheusJob, AttributeValueToString(prometheus_job_it->second),
+                           &metric.label);
+        break;
+      }
+
+      opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
+          resource->GetAttributes().find(
+              opentelemetry::sdk::resource::SemanticConventions::kServiceName);
+      opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_namespace_it =
+          resource->GetAttributes().find(
+              opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace);
+
+      if (service_namespace_it != resource->GetAttributes().end() &&
+          service_name_it != resource->GetAttributes().end())
+      {
+        AddPrometheusLabel(kPrometheusJob,
+                           AttributeValueToString(service_namespace_it->second) + "/" +
+                               AttributeValueToString(service_name_it->second),
+                           &metric.label);
+      }
+      else if (service_name_it != resource->GetAttributes().end())
+      {
+        AddPrometheusLabel(kPrometheusJob, AttributeValueToString(service_name_it->second),
+                           &metric.label);
+      }
+      else if (service_namespace_it != resource->GetAttributes().end())
+      {
+        AddPrometheusLabel(kPrometheusJob,
+                           AttributeValueToString(service_namespace_it->second) + "/",
+                           &metric.label);
+      }
+    } while (false);
+
+    if (!has_instance_label)
+    {
+      opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_instance_id_it =
+          resource->GetAttributes().find(
+              opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
+      if (service_instance_id_it == resource->GetAttributes().end())
+      {
+        service_instance_id_it = resource->GetAttributes().find(kPrometheusInstance);
+      }
+      if (service_instance_id_it != resource->GetAttributes().end())
+      {
+        has_instance_label = true;
+        AddPrometheusLabel(kPrometheusInstance,
+                           AttributeValueToString(service_instance_id_it->second), &metric.label);
+      }
+    }
+  }
+
+  // Add a empty instance label if it's not exist
   if (!has_instance_label)
   {
     AddPrometheusLabel(kPrometheusInstance, "", &metric.label);
diff --git a/exporters/prometheus/test/collector_test.cc b/exporters/prometheus/test/collector_test.cc
index d422c45c5b..e711e8bdc7 100644
--- a/exporters/prometheus/test/collector_test.cc
+++ b/exporters/prometheus/test/collector_test.cc
@@ -76,7 +76,7 @@ TEST(PrometheusCollector, BasicTests)
 
   // Collection size should be the same as the size
   // of the records collection produced by MetricProducer.
-  ASSERT_EQ(data.size(), 1);
+  ASSERT_EQ(data.size(), 2);
   delete reader;
   delete producer;
 }
diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index a2591b103d..d603743475 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -117,16 +117,32 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerCounter)
   metrics_data.resource_                   = &resource;
 
   auto translated = PrometheusExporterUtils::TranslateToPrometheus(metrics_data);
-  ASSERT_EQ(translated.size(), 1);
+  ASSERT_EQ(translated.size(), 2);
 
-  auto metric1          = translated[0];
+  auto metric1          = translated[1];
   std::vector<int> vals = {10};
 
-  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter,
-               resource.GetAttributes().size(), vals);
+  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter, 3,
+               vals);
 
   int checked_label_num = 0;
   for (auto &label : metric1.metric[0].label)
+  {
+    if (label.name == "job")
+    {
+      ASSERT_EQ(label.value, "test_namespace/test_service");
+      checked_label_num++;
+    }
+    else if (label.name == "instance")
+    {
+      ASSERT_EQ(label.value, "localhost:8000");
+      checked_label_num++;
+    }
+  }
+  ASSERT_EQ(checked_label_num, 2);
+
+  checked_label_num = 0;
+  for (auto &label : translated[0].metric[0].label)
   {
     if (label.name == "job")
     {
@@ -157,15 +173,31 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerLastValue)
   metrics_data.resource_                   = &resource;
 
   auto translated = PrometheusExporterUtils::TranslateToPrometheus(metrics_data);
-  ASSERT_EQ(translated.size(), 1);
+  ASSERT_EQ(translated.size(), 2);
 
-  auto metric1          = translated[0];
+  auto metric1          = translated[1];
   std::vector<int> vals = {10};
-  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Gauge,
-               resource.GetAttributes().size() + 1, vals);
+  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Gauge, 3,
+               vals);
 
   int checked_label_num = 0;
   for (auto &label : metric1.metric[0].label)
+  {
+    if (label.name == "job")
+    {
+      ASSERT_EQ(label.value, "test_service");
+      checked_label_num++;
+    }
+    else if (label.name == "instance")
+    {
+      ASSERT_EQ(label.value, "localhost:8000");
+      checked_label_num++;
+    }
+  }
+  ASSERT_EQ(checked_label_num, 2);
+
+  checked_label_num = 0;
+  for (auto &label : translated[0].metric[0].label)
   {
     if (label.name == "job")
     {
@@ -188,16 +220,58 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerLastValue)
 
 TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)
 {
+  opentelemetry::sdk::resource::Resource resource = opentelemetry::sdk::resource::Resource::Create(
+      {{"job", "test_service2"},
+       {"instance", "localhost:8001"},
+       {"custom_resource_attr", "custom_resource_value"}});
   metric_sdk::ResourceMetrics metrics_data = CreateHistogramPointData();
+  metrics_data.resource_                   = &resource;
 
   auto translated = PrometheusExporterUtils::TranslateToPrometheus(metrics_data);
-  ASSERT_EQ(translated.size(), 1);
+  ASSERT_EQ(translated.size(), 2);
 
-  auto metric              = translated[0];
+  auto metric              = translated[1];
   std::vector<double> vals = {3, 900.5, 4};
-  assert_basic(metric, "library_name", "description", prometheus_client::MetricType::Histogram,
-               metrics_data.resource_->GetAttributes().size() + 1, vals);
+  assert_basic(metric, "library_name", "description", prometheus_client::MetricType::Histogram, 3,
+               vals);
   assert_histogram(metric, std::list<double>{10.1, 20.2, 30.2}, {200, 300, 400, 500});
+
+  int checked_label_num = 0;
+  for (auto &label : metric.metric[0].label)
+  {
+    if (label.name == "job")
+    {
+      ASSERT_EQ(label.value, "test_service2");
+      checked_label_num++;
+    }
+    else if (label.name == "instance")
+    {
+      ASSERT_EQ(label.value, "localhost:8001");
+      checked_label_num++;
+    }
+  }
+  ASSERT_EQ(checked_label_num, 2);
+
+  checked_label_num = 0;
+  for (auto &label : translated[0].metric[0].label)
+  {
+    if (label.name == "job")
+    {
+      ASSERT_EQ(label.value, "test_service2");
+      checked_label_num++;
+    }
+    else if (label.name == "instance")
+    {
+      ASSERT_EQ(label.value, "localhost:8001");
+      checked_label_num++;
+    }
+    else if (label.name == "custom_resource_attr")
+    {
+      ASSERT_EQ(label.value, "custom_resource_value");
+      checked_label_num++;
+    }
+  }
+  ASSERT_EQ(checked_label_num, 3);
 }
 
 TEST(PrometheusExporterUtils, SanitizeName)

From 72ed7516fada5ef63ceae21157112aefd646f120 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Tue, 19 Sep 2023 23:09:31 +0800
Subject: [PATCH 09/25] Add options to let user to decide whether to populate
 target_info

---
 .../exporters/prometheus/collector.h          |  3 +-
 .../exporters/prometheus/exporter_options.h   |  3 ++
 .../exporters/prometheus/exporter_utils.h     |  6 ++--
 exporters/prometheus/src/collector.cc         | 17 ++++++++--
 exporters/prometheus/src/exporter.cc          |  3 +-
 exporters/prometheus/src/exporter_utils.cc    | 32 +++++++------------
 exporters/prometheus/test/collector_test.cc   |  2 +-
 7 files changed, 37 insertions(+), 29 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/collector.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/collector.h
index 46d270905b..5dfa983088 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/collector.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/collector.h
@@ -31,7 +31,7 @@ class PrometheusCollector : public prometheus_client::Collectable
    * This constructor initializes the collection for metrics to export
    * in this class with default capacity
    */
-  explicit PrometheusCollector(sdk::metrics::MetricReader *reader);
+  explicit PrometheusCollector(sdk::metrics::MetricReader *reader, bool populate_target_info);
 
   /**
    * Collects all metrics data from metricsToCollect collection.
@@ -42,6 +42,7 @@ class PrometheusCollector : public prometheus_client::Collectable
 
 private:
   sdk::metrics::MetricReader *reader_;
+  bool populate_target_info_;
 
   /*
    * Lock when operating the metricsToCollect collection
diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_options.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_options.h
index 76a08d2a4a..3f36d780ee 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_options.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_options.h
@@ -22,6 +22,9 @@ struct PrometheusExporterOptions
 
   // The endpoint the Prometheus backend can collect metrics from
   std::string url;
+
+  // Populating target_info
+  bool populate_target_info = true;
 };
 
 }  // namespace metrics
diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index 67b1535968..6a4163f740 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -26,10 +26,12 @@ class PrometheusExporterUtils
    * to Prometheus metrics data collection
    *
    * @param records a collection of metrics in OpenTelemetry
+   * @param populate_target_info whether to populate target_info
    * @return a collection of translated metrics that is acceptable by Prometheus
    */
   static std::vector<::prometheus::MetricFamily> TranslateToPrometheus(
-      const sdk::metrics::ResourceMetrics &data);
+      const sdk::metrics::ResourceMetrics &data,
+      bool populate_target_info = true);
 
 private:
   /**
@@ -47,8 +49,6 @@ class PrometheusExporterUtils
    * @param name label name
    * @param value label value
    * @param labels target labels
-   *
-   * @return true if the attribute should be ignored, false otherwise.
    */
   static void AddPrometheusLabel(std::string name,
                                  std::string value,
diff --git a/exporters/prometheus/src/collector.cc b/exporters/prometheus/src/collector.cc
index 29c0bc8db2..3dde2beaee 100644
--- a/exporters/prometheus/src/collector.cc
+++ b/exporters/prometheus/src/collector.cc
@@ -17,7 +17,10 @@ namespace metrics
  * This constructor initializes the collection for metrics to export
  * in this class with default capacity
  */
-PrometheusCollector::PrometheusCollector(sdk::metrics::MetricReader *reader) : reader_(reader) {}
+PrometheusCollector::PrometheusCollector(sdk::metrics::MetricReader *reader,
+                                         bool populate_target_info)
+    : reader_(reader), populate_target_info_(populate_target_info)
+{}
 
 /**
  * Collects all metrics data from metricsToCollect collection.
@@ -36,7 +39,17 @@ std::vector<prometheus_client::MetricFamily> PrometheusCollector::Collect() cons
   collection_lock_.lock();
 
   std::vector<prometheus_client::MetricFamily> result;
-  reader_->Collect([&result](sdk::metrics::ResourceMetrics &metric_data) {
+
+  // If populate_target_info_ is true, populate target_info once.
+  bool populate_target_info = false;
+  if (populate_target_info_)
+  {
+    populate_target_info = true;
+
+    const_cast<PrometheusCollector *>(this)->populate_target_info_ = false;
+  }
+
+  reader_->Collect([&result, populate_target_info](sdk::metrics::ResourceMetrics &metric_data) {
     auto prometheus_metric_data = PrometheusExporterUtils::TranslateToPrometheus(metric_data);
     for (auto &data : prometheus_metric_data)
       result.emplace_back(data);
diff --git a/exporters/prometheus/src/exporter.cc b/exporters/prometheus/src/exporter.cc
index 7691e32f39..6022c2c33b 100644
--- a/exporters/prometheus/src/exporter.cc
+++ b/exporters/prometheus/src/exporter.cc
@@ -30,7 +30,8 @@ PrometheusExporter::PrometheusExporter(const PrometheusExporterOptions &options)
     Shutdown();  // set MetricReader in shutdown state.
     return;
   }
-  collector_ = std::shared_ptr<PrometheusCollector>(new PrometheusCollector(this));
+  collector_ = std::shared_ptr<PrometheusCollector>(
+      new PrometheusCollector(this, options_.populate_target_info));
 
   exposer_->RegisterCollectable(collector_);
 }
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 0e76421a80..997374be85 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -39,7 +39,8 @@ static constexpr const char *kPrometheusJob      = "job";
  * @return a collection of translated metrics that is acceptable by Prometheus
  */
 std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateToPrometheus(
-    const sdk::metrics::ResourceMetrics &data)
+    const sdk::metrics::ResourceMetrics &data,
+    bool populate_target_info)
 {
 
   // initialize output vector
@@ -53,7 +54,10 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
   output.reserve(reserve_size);
 
   // Append target_info as the first metric
-  SetTarget(data, &output);
+  if (populate_target_info)
+  {
+    SetTarget(data, &output);
+  }
 
   for (const auto &instrumentation_info : data.scope_metric_data_)
   {
@@ -291,16 +295,8 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
   prometheus_client::ClientMetric &metric = metric_family.metric.back();
   metric.info.value                       = 1.0;
 
-  std::chrono::nanoseconds time;
-  for (const auto &instrumentation_info : data.scope_metric_data_)
-  {
-    for (const auto &metric_data : instrumentation_info.metric_data_)
-    {
-      time = metric_data.end_ts.time_since_epoch();
-      break;
-    }
-    break;
-  }
+  std::chrono::nanoseconds time =
+      (*data.scope_metric_data_.begin()).metric_data_.begin()->end_ts.time_since_epoch();
 
   metric_sdk::PointAttributes empty_attributes;
   SetMetricBasic(metric, time, empty_attributes, data.resource_);
@@ -442,22 +438,16 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
         AddPrometheusLabel(kPrometheusJob, AttributeValueToString(service_name_it->second),
                            &metric.label);
       }
-      else if (service_namespace_it != resource->GetAttributes().end())
-      {
-        AddPrometheusLabel(kPrometheusJob,
-                           AttributeValueToString(service_namespace_it->second) + "/",
-                           &metric.label);
-      }
     } while (false);
 
     if (!has_instance_label)
     {
       opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_instance_id_it =
-          resource->GetAttributes().find(
-              opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
+          resource->GetAttributes().find(kPrometheusInstance);
       if (service_instance_id_it == resource->GetAttributes().end())
       {
-        service_instance_id_it = resource->GetAttributes().find(kPrometheusInstance);
+        service_instance_id_it = resource->GetAttributes().find(
+            opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
       }
       if (service_instance_id_it != resource->GetAttributes().end())
       {
diff --git a/exporters/prometheus/test/collector_test.cc b/exporters/prometheus/test/collector_test.cc
index e711e8bdc7..4d1147aa2f 100644
--- a/exporters/prometheus/test/collector_test.cc
+++ b/exporters/prometheus/test/collector_test.cc
@@ -71,7 +71,7 @@ TEST(PrometheusCollector, BasicTests)
   MockMetricReader *reader     = new MockMetricReader();
   MockMetricProducer *producer = new MockMetricProducer();
   reader->SetMetricProducer(producer);
-  PrometheusCollector collector(reader);
+  PrometheusCollector collector(reader, true);
   auto data = collector.Collect();
 
   // Collection size should be the same as the size

From 00b0b6673a047ead45f9b19befe62553fdb1ba1e Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Tue, 19 Sep 2023 23:56:07 +0800
Subject: [PATCH 10/25] Fix warnings

---
 exporters/prometheus/src/collector.cc      |  3 ++-
 exporters/prometheus/src/exporter_utils.cc | 11 ++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/exporters/prometheus/src/collector.cc b/exporters/prometheus/src/collector.cc
index 3dde2beaee..b066f3eb7b 100644
--- a/exporters/prometheus/src/collector.cc
+++ b/exporters/prometheus/src/collector.cc
@@ -50,7 +50,8 @@ std::vector<prometheus_client::MetricFamily> PrometheusCollector::Collect() cons
   }
 
   reader_->Collect([&result, populate_target_info](sdk::metrics::ResourceMetrics &metric_data) {
-    auto prometheus_metric_data = PrometheusExporterUtils::TranslateToPrometheus(metric_data);
+    auto prometheus_metric_data =
+        PrometheusExporterUtils::TranslateToPrometheus(metric_data, populate_target_info);
     for (auto &data : prometheus_metric_data)
       result.emplace_back(data);
     return true;
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 997374be85..e8ef83aca9 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -1,6 +1,7 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+#include <limits>
 #include <sstream>
 #include <string>
 #include <unordered_map>
@@ -94,7 +95,7 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
           }
           else
           {
-            sum = nostd::get<int64_t>(histogram_point_data.sum_);
+            sum = static_cast<double>(nostd::get<int64_t>(histogram_point_data.sum_));
           }
           SetData(std::vector<double>{sum, (double)histogram_point_data.count_}, boundaries, counts,
                   point_data_attr.attributes, time, &metric_family, data.resource_);
@@ -518,7 +519,7 @@ void PrometheusExporterUtils::SetValue(std::vector<T> values,
   const auto &value_var = values[0];
   if (nostd::holds_alternative<int64_t>(value_var))
   {
-    value = nostd::get<int64_t>(value_var);
+    value = static_cast<double>(nostd::get<int64_t>(value_var));
   }
   else
   {
@@ -553,9 +554,9 @@ void PrometheusExporterUtils::SetValue(std::vector<T> values,
                                        const std::vector<uint64_t> &counts,
                                        prometheus_client::ClientMetric *metric)
 {
-  metric->histogram.sample_sum   = values[0];
-  metric->histogram.sample_count = values[1];
-  int cumulative                 = 0;
+  metric->histogram.sample_sum   = static_cast<double>(values[0]);
+  metric->histogram.sample_count = static_cast<std::uint64_t>(values[1]);
+  std::uint64_t cumulative       = 0;
   std::vector<prometheus_client::ClientMetric::Bucket> buckets;
   uint32_t idx = 0;
   for (const auto &boundary : boundaries)

From 9f01fd4cc4e5a5db736111fc58f8958cfdaf7e84 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 21 Sep 2023 21:22:15 +0800
Subject: [PATCH 11/25] Fix priority of conflict labels.

---
 exporters/prometheus/src/exporter_utils.cc | 25 +++++++++++-----------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index e8ef83aca9..71007b3f54 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -410,15 +410,6 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
         break;
       }
 
-      opentelemetry::sdk::resource::ResourceAttributes::const_iterator prometheus_job_it =
-          resource->GetAttributes().find(kPrometheusJob);
-      if (prometheus_job_it != resource->GetAttributes().end())
-      {
-        AddPrometheusLabel(kPrometheusJob, AttributeValueToString(prometheus_job_it->second),
-                           &metric.label);
-        break;
-      }
-
       opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
           resource->GetAttributes().find(
               opentelemetry::sdk::resource::SemanticConventions::kServiceName);
@@ -433,22 +424,32 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
                            AttributeValueToString(service_namespace_it->second) + "/" +
                                AttributeValueToString(service_name_it->second),
                            &metric.label);
+        break;
       }
       else if (service_name_it != resource->GetAttributes().end())
       {
         AddPrometheusLabel(kPrometheusJob, AttributeValueToString(service_name_it->second),
                            &metric.label);
+        break;
+      }
+
+      opentelemetry::sdk::resource::ResourceAttributes::const_iterator prometheus_job_it =
+          resource->GetAttributes().find(kPrometheusJob);
+      if (prometheus_job_it != resource->GetAttributes().end())
+      {
+        AddPrometheusLabel(kPrometheusJob, AttributeValueToString(prometheus_job_it->second),
+                           &metric.label);
       }
     } while (false);
 
     if (!has_instance_label)
     {
       opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_instance_id_it =
-          resource->GetAttributes().find(kPrometheusInstance);
+          resource->GetAttributes().find(
+              opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
       if (service_instance_id_it == resource->GetAttributes().end())
       {
-        service_instance_id_it = resource->GetAttributes().find(
-            opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
+        service_instance_id_it = resource->GetAttributes().find(kPrometheusInstance);
       }
       if (service_instance_id_it != resource->GetAttributes().end())
       {

From 5d24d88c64d89ffffbd2ca09c1b5db4d04306cc2 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 21 Sep 2023 21:54:04 +0800
Subject: [PATCH 12/25] Fix unit test

---
 exporters/prometheus/test/exporter_utils_test.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index d603743475..e24c546848 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -241,7 +241,8 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)
   {
     if (label.name == "job")
     {
-      ASSERT_EQ(label.value, "test_service2");
+      // job label should be ignored when service.name exist
+      ASSERT_EQ(label.value, "unknown_service");
       checked_label_num++;
     }
     else if (label.name == "instance")

From e50a3d6ccfcabc0157e3b7b63275bfb830eff7db Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 21 Sep 2023 22:43:22 +0800
Subject: [PATCH 13/25] Allow some attributes in resource attributes but not in
 metric attributes

---
 .../exporters/prometheus/exporter_utils.h           |  9 +++++++++
 exporters/prometheus/src/exporter_utils.cc          | 13 +++++++++++--
 exporters/prometheus/test/exporter_utils_test.cc    |  3 ++-
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index 6a4163f740..ff2fc9faa9 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -63,6 +63,15 @@ class PrometheusExporterUtils
    */
   static bool ShouldIgnoreResourceAttribute(const std::string &name);
 
+  /**
+   * Some attributes should be ignored when converting metric attributes to
+   * prometheus labels.
+   *
+   * @param name attribute name
+   * @return true if the attribute should be ignored, false otherwise.
+   */
+  static bool ShouldIgnoreMetricAttribute(const std::string &name);
+
   static opentelemetry::sdk::metrics::AggregationType getAggregationType(
       const opentelemetry::sdk::metrics::PointType &point_type);
 
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 71007b3f54..a6ba93ea6f 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -209,10 +209,19 @@ bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &n
   static std::unordered_set<std::string> ignores{
       opentelemetry::sdk::resource::SemanticConventions::kServiceName,
       opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace,
+      opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId, kPrometheusJob,
+      kPrometheusInstance};
+  return ignores.end() != ignores.find(name);
+}
+
+bool PrometheusExporterUtils::ShouldIgnoreMetricAttribute(const std::string &name)
+{
+  static std::unordered_set<std::string> ignores{
+      opentelemetry::sdk::resource::SemanticConventions::kServiceName,
+      opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId,
       opentelemetry::trace::SemanticConventions::kServerAddress,
       opentelemetry::trace::SemanticConventions::kServerPort,
       opentelemetry::trace::SemanticConventions::kUrlScheme,
-      opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId,
       kPrometheusJob,
       kPrometheusInstance};
   return ignores.end() != ignores.find(name);
@@ -381,7 +390,7 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   {
     for (auto &label : labels)
     {
-      if (ShouldIgnoreResourceAttribute(label.first))
+      if (ShouldIgnoreMetricAttribute(label.first))
       {
         continue;
       }
diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index e24c546848..fb30c13d46 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -258,7 +258,8 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)
   {
     if (label.name == "job")
     {
-      ASSERT_EQ(label.value, "test_service2");
+      // job label should be ignored when service.name exist
+      ASSERT_EQ(label.value, "unknown_service");
       checked_label_num++;
     }
     else if (label.name == "instance")

From 88e98572059ecb3742f239746367c7a0d776bdb8 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 21 Sep 2023 23:36:02 +0800
Subject: [PATCH 14/25] Change the info-typed target metric.

---
 exporters/prometheus/src/exporter_utils.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index a6ba93ea6f..bb84f0c4c4 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -297,7 +297,7 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
   }
 
   prometheus_client::MetricFamily metric_family;
-  metric_family.name = "target_info";
+  metric_family.name = "target";
   metric_family.help = "Target metadata";
   metric_family.type = prometheus_client::MetricType::Info;
   metric_family.metric.emplace_back();

From a0b322bf0fce6597b80eab7e3a983c080b1fc269 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Fri, 22 Sep 2023 00:06:30 +0800
Subject: [PATCH 15/25] Do not ignore metric attributes.

---
 .../exporters/prometheus/exporter_utils.h      |  9 ---------
 exporters/prometheus/src/exporter_utils.cc     | 18 ------------------
 2 files changed, 27 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index ff2fc9faa9..6a4163f740 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -63,15 +63,6 @@ class PrometheusExporterUtils
    */
   static bool ShouldIgnoreResourceAttribute(const std::string &name);
 
-  /**
-   * Some attributes should be ignored when converting metric attributes to
-   * prometheus labels.
-   *
-   * @param name attribute name
-   * @return true if the attribute should be ignored, false otherwise.
-   */
-  static bool ShouldIgnoreMetricAttribute(const std::string &name);
-
   static opentelemetry::sdk::metrics::AggregationType getAggregationType(
       const opentelemetry::sdk::metrics::PointType &point_type);
 
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index bb84f0c4c4..53cdeca9f4 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -214,19 +214,6 @@ bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &n
   return ignores.end() != ignores.find(name);
 }
 
-bool PrometheusExporterUtils::ShouldIgnoreMetricAttribute(const std::string &name)
-{
-  static std::unordered_set<std::string> ignores{
-      opentelemetry::sdk::resource::SemanticConventions::kServiceName,
-      opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId,
-      opentelemetry::trace::SemanticConventions::kServerAddress,
-      opentelemetry::trace::SemanticConventions::kServerPort,
-      opentelemetry::trace::SemanticConventions::kUrlScheme,
-      kPrometheusJob,
-      kPrometheusInstance};
-  return ignores.end() != ignores.find(name);
-}
-
 metric_sdk::AggregationType PrometheusExporterUtils::getAggregationType(
     const metric_sdk::PointType &point_type)
 {
@@ -390,11 +377,6 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   {
     for (auto &label : labels)
     {
-      if (ShouldIgnoreMetricAttribute(label.first))
-      {
-        continue;
-      }
-
       std::string label_name = SanitizeNames(label.first);
       if (label_name == kPrometheusInstance)
       {

From fcc397f13534b3a264074cf708bac61ee63ee98c Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Wed, 27 Sep 2023 16:02:31 +0800
Subject: [PATCH 16/25] Fix unit tests after merged.

---
 .../prometheus/test/exporter_utils_test.cc    | 26 ++++++++++++++++---
 .../sdk/metrics/export/metric_producer.h      |  5 ++--
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index 4b9733c316..dc719b0b44 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -283,7 +283,11 @@ class SanitizeNameTest : public ::testing::Test
         metric_sdk::InstrumentValueType::kDouble};
     std::vector<prometheus::MetricFamily> result = PrometheusExporterUtils::TranslateToPrometheus(
         {&resource_,
-         {{instrumentation_scope_.get(), {{instrument_descriptor_, {}, {}, {}, {{{}, {}}}}}}}});
+         std::vector<metric_sdk::ScopeMetrics>{
+             {instrumentation_scope_.get(),
+              std::vector<metric_sdk::MetricData>{
+                  {instrument_descriptor_, {}, {}, {}, {{{}, {}}}}}}}},
+        false);
     EXPECT_EQ(result.begin()->name, sanitized + "_unit");
   }
 };
@@ -313,8 +317,24 @@ class AttributeCollisionTest : public ::testing::Test
   {
     std::vector<prometheus::MetricFamily> result = PrometheusExporterUtils::TranslateToPrometheus(
         {&resource_,
-         {{instrumentation_scope_.get(), {{instrument_descriptor_, {}, {}, {}, {{attrs, {}}}}}}}});
-    EXPECT_EQ(result.begin()->metric.begin()->label, expected);
+         std::vector<metric_sdk::ScopeMetrics>{
+             {instrumentation_scope_.get(),
+              std::vector<metric_sdk::MetricData>{
+                  {instrument_descriptor_, {}, {}, {}, {{attrs, {}}}}}}}},
+        false);
+    for (auto &expected_kv : expected)
+    {
+      bool found = false;
+      for (auto &found_kv : result.begin()->metric.begin()->label)
+      {
+        if (found_kv.name == expected_kv.name)
+        {
+          EXPECT_EQ(found_kv.value, expected_kv.value);
+          found = true;
+        }
+      }
+      EXPECT_TRUE(found);
+    }
   }
 };
 
diff --git a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
index 4bd5b131fb..11eb113e1e 100644
--- a/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
+++ b/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h
@@ -37,7 +37,7 @@ struct ScopeMetrics
 
   template <class ScopePtr, class MetricDataType>
   inline ScopeMetrics(ScopePtr &&scope, MetricDataType &&metric)
-      : scope_{std::move(scope)}, metric_data_{std::move(metric)}
+      : scope_{std::forward<ScopePtr>(scope)}, metric_data_{std::forward<MetricDataType>(metric)}
   {}
 
   inline ScopeMetrics() {}
@@ -56,7 +56,8 @@ struct ResourceMetrics
 
   template <class ResourcePtr, class ScopeMetricsType>
   inline ResourceMetrics(ResourcePtr &&resource, ScopeMetricsType &&scope_metric_data)
-      : resource_{std::move(resource)}, scope_metric_data_{std::move(scope_metric_data)}
+      : resource_{std::forward<ResourcePtr>(resource)},
+        scope_metric_data_{std::forward<ScopeMetricsType>(scope_metric_data)}
   {}
 
   inline ResourceMetrics() {}

From 765eb99d1ee4891a98903b47cad0f503a9b7aea4 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Wed, 27 Sep 2023 16:43:31 +0800
Subject: [PATCH 17/25] Merge SanitizeName changes

---
 exporters/prometheus/src/exporter_utils.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 55c4017876..62e3997825 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -334,7 +334,7 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
       continue;
     }
 
-    AddPrometheusLabel(SanitizeNames(label.first), AttributeValueToString(label.second),
+    AddPrometheusLabel(SanitizeName(label.first), AttributeValueToString(label.second),
                        &metric.label);
   }
 

From c47693935883defa7e1991ea58048ec47c0ac4f7 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Thu, 28 Sep 2023 16:22:23 +0800
Subject: [PATCH 18/25] Remove ignores in resource attributes

---
 .../exporters/prometheus/exporter_utils.h     |  9 ---
 exporters/prometheus/src/exporter_utils.cc    | 71 ++++---------------
 .../prometheus/test/exporter_utils_test.cc    |  3 +-
 3 files changed, 13 insertions(+), 70 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index 3ff0e58b0a..0b60639995 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -45,15 +45,6 @@ class PrometheusExporterUtils
                                  std::string value,
                                  std::vector<::prometheus::ClientMetric::Label> *labels);
 
-  /**
-   * Some attributes should be ignored when converting resource attributes to
-   * prometheus labels.
-   *
-   * @param name resource attribute name
-   * @return true if the attribute should be ignored, false otherwise.
-   */
-  static bool ShouldIgnoreResourceAttribute(const std::string &name);
-
   static opentelemetry::sdk::metrics::AggregationType getAggregationType(
       const opentelemetry::sdk::metrics::PointType &point_type);
 
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 62e3997825..e784f23211 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -236,16 +236,6 @@ void PrometheusExporterUtils::AddPrometheusLabel(
   labels->emplace_back(std::move(prometheus_label));
 }
 
-bool PrometheusExporterUtils::ShouldIgnoreResourceAttribute(const std::string &name)
-{
-  static std::unordered_set<std::string> ignores{
-      opentelemetry::sdk::resource::SemanticConventions::kServiceName,
-      opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace,
-      opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId, kPrometheusJob,
-      kPrometheusInstance};
-  return ignores.end() != ignores.find(name);
-}
-
 metric_sdk::AggregationType PrometheusExporterUtils::getAggregationType(
     const metric_sdk::PointType &point_type)
 {
@@ -329,11 +319,6 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
 
   for (auto &label : data.resource_->GetAttributes())
   {
-    if (ShouldIgnoreResourceAttribute(label.first))
-    {
-      continue;
-    }
-
     AddPrometheusLabel(SanitizeName(label.first), AttributeValueToString(label.second),
                        &metric.label);
   }
@@ -394,20 +379,9 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   // in this hot code path. Instead, we ignore out-of-order keys and emit a warning.
   metric.label.reserve(labels.size() + 2);
   std::string previous_key;
-  bool has_instance_label = false;
-  bool has_job_label      = false;
   for (auto const &label : labels)
   {
     auto sanitized = SanitizeLabel(label.first);
-    if (!has_instance_label && sanitized == kPrometheusInstance)
-    {
-      has_instance_label = true;
-    }
-    else if (!has_job_label && sanitized == kPrometheusJob)
-    {
-      has_job_label = true;
-    }
-
     int comparison = previous_key.compare(sanitized);
     if (metric.label.empty() || comparison < 0)  // new key
     {
@@ -433,11 +407,6 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
   {
     do
     {
-      if (has_job_label)
-      {
-        break;
-      }
-
       opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
           resource->GetAttributes().find(
               opentelemetry::sdk::resource::SemanticConventions::kServiceName);
@@ -460,38 +429,22 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
                            &metric.label);
         break;
       }
-
-      opentelemetry::sdk::resource::ResourceAttributes::const_iterator prometheus_job_it =
-          resource->GetAttributes().find(kPrometheusJob);
-      if (prometheus_job_it != resource->GetAttributes().end())
-      {
-        AddPrometheusLabel(kPrometheusJob, AttributeValueToString(prometheus_job_it->second),
-                           &metric.label);
-      }
     } while (false);
 
-    if (!has_instance_label)
+    opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_instance_id_it =
+        resource->GetAttributes().find(
+            opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
+
+    if (service_instance_id_it != resource->GetAttributes().end())
     {
-      opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_instance_id_it =
-          resource->GetAttributes().find(
-              opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
-      if (service_instance_id_it == resource->GetAttributes().end())
-      {
-        service_instance_id_it = resource->GetAttributes().find(kPrometheusInstance);
-      }
-      if (service_instance_id_it != resource->GetAttributes().end())
-      {
-        has_instance_label = true;
-        AddPrometheusLabel(kPrometheusInstance,
-                           AttributeValueToString(service_instance_id_it->second), &metric.label);
-      }
+      AddPrometheusLabel(kPrometheusInstance,
+                         AttributeValueToString(service_instance_id_it->second), &metric.label);
+    }
+    else
+    {
+      // Add a empty instance label if it's not exist
+      AddPrometheusLabel(kPrometheusInstance, "", &metric.label);
     }
-  }
-
-  // Add a empty instance label if it's not exist
-  if (!has_instance_label)
-  {
-    AddPrometheusLabel(kPrometheusInstance, "", &metric.label);
   }
 }
 
diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index a269d71556..df6fdde7d7 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -213,8 +213,7 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerLastValue)
 TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)
 {
   opentelemetry::sdk::resource::Resource resource = opentelemetry::sdk::resource::Resource::Create(
-      {{"job", "test_service2"},
-       {"instance", "localhost:8001"},
+      {{"service.instance.id", "localhost:8001"},
        {"custom_resource_attr", "custom_resource_value"}});
   TestDataPoints dp;
   metric_sdk::ResourceMetrics metrics_data = dp.CreateHistogramPointData();

From 422bca272dd984086ef82410a7901f1ff6414cca Mon Sep 17 00:00:00 2001
From: WenTao Ou <admin@owent.net>
Date: Fri, 29 Sep 2023 13:49:56 +0800
Subject: [PATCH 19/25] Remove labels conversations that should only be in
 target info.

Signed-off-by: WenTao Ou <admin@owent.net>
---
 exporters/prometheus/src/exporter_utils.cc    | 53 -------------
 .../prometheus/test/exporter_utils_test.cc    | 74 ++++---------------
 2 files changed, 15 insertions(+), 112 deletions(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index e784f23211..4e5b75707a 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -296,14 +296,6 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
   {
     return;
   }
-  if (data.scope_metric_data_.empty())
-  {
-    return;
-  }
-  if ((*data.scope_metric_data_.begin()).metric_data_.empty())
-  {
-    return;
-  }
 
   prometheus_client::MetricFamily metric_family;
   metric_family.name = "target";
@@ -401,51 +393,6 @@ void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &me
           << "'. Ignoring this label.");
     }
   }
-
-  // Convert resource to job and instance labels
-  if (nullptr != resource)
-  {
-    do
-    {
-      opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_name_it =
-          resource->GetAttributes().find(
-              opentelemetry::sdk::resource::SemanticConventions::kServiceName);
-      opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_namespace_it =
-          resource->GetAttributes().find(
-              opentelemetry::sdk::resource::SemanticConventions::kServiceNamespace);
-
-      if (service_namespace_it != resource->GetAttributes().end() &&
-          service_name_it != resource->GetAttributes().end())
-      {
-        AddPrometheusLabel(kPrometheusJob,
-                           AttributeValueToString(service_namespace_it->second) + "/" +
-                               AttributeValueToString(service_name_it->second),
-                           &metric.label);
-        break;
-      }
-      else if (service_name_it != resource->GetAttributes().end())
-      {
-        AddPrometheusLabel(kPrometheusJob, AttributeValueToString(service_name_it->second),
-                           &metric.label);
-        break;
-      }
-    } while (false);
-
-    opentelemetry::sdk::resource::ResourceAttributes::const_iterator service_instance_id_it =
-        resource->GetAttributes().find(
-            opentelemetry::sdk::resource::SemanticConventions::kServiceInstanceId);
-
-    if (service_instance_id_it != resource->GetAttributes().end())
-    {
-      AddPrometheusLabel(kPrometheusInstance,
-                         AttributeValueToString(service_instance_id_it->second), &metric.label);
-    }
-    else
-    {
-      // Add a empty instance label if it's not exist
-      AddPrometheusLabel(kPrometheusInstance, "", &metric.label);
-    }
-  }
 }
 
 std::string PrometheusExporterUtils::AttributeValueToString(
diff --git a/exporters/prometheus/test/exporter_utils_test.cc b/exporters/prometheus/test/exporter_utils_test.cc
index df6fdde7d7..64f3b8ddf4 100644
--- a/exporters/prometheus/test/exporter_utils_test.cc
+++ b/exporters/prometheus/test/exporter_utils_test.cc
@@ -113,34 +113,23 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerCounter)
   auto metric1          = translated[1];
   std::vector<int> vals = {10};
 
-  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter, 3,
+  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Counter, 1,
                vals);
 
   int checked_label_num = 0;
-  for (auto &label : metric1.metric[0].label)
+  for (auto &label : translated[0].metric[0].label)
   {
-    if (label.name == "job")
+    if (label.name == "service_namespace")
     {
-      ASSERT_EQ(label.value, "test_namespace/test_service");
-      checked_label_num++;
-    }
-    else if (label.name == "instance")
-    {
-      ASSERT_EQ(label.value, "localhost:8000");
+      ASSERT_EQ(label.value, "test_namespace");
       checked_label_num++;
     }
-  }
-  ASSERT_EQ(checked_label_num, 2);
-
-  checked_label_num = 0;
-  for (auto &label : translated[0].metric[0].label)
-  {
-    if (label.name == "job")
+    else if (label.name == "service_name")
     {
-      ASSERT_EQ(label.value, "test_namespace/test_service");
+      ASSERT_EQ(label.value, "test_service");
       checked_label_num++;
     }
-    else if (label.name == "instance")
+    else if (label.name == "service_instance_id")
     {
       ASSERT_EQ(label.value, "localhost:8000");
       checked_label_num++;
@@ -151,7 +140,7 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerCounter)
       checked_label_num++;
     }
   }
-  ASSERT_EQ(checked_label_num, 3);
+  ASSERT_EQ(checked_label_num, 4);
 }
 
 TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerLastValue)
@@ -169,34 +158,18 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusIntegerLastValue)
 
   auto metric1          = translated[1];
   std::vector<int> vals = {10};
-  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Gauge, 3,
+  assert_basic(metric1, "library_name", "description", prometheus_client::MetricType::Gauge, 1,
                vals);
 
   int checked_label_num = 0;
-  for (auto &label : metric1.metric[0].label)
-  {
-    if (label.name == "job")
-    {
-      ASSERT_EQ(label.value, "test_service");
-      checked_label_num++;
-    }
-    else if (label.name == "instance")
-    {
-      ASSERT_EQ(label.value, "localhost:8000");
-      checked_label_num++;
-    }
-  }
-  ASSERT_EQ(checked_label_num, 2);
-
-  checked_label_num = 0;
   for (auto &label : translated[0].metric[0].label)
   {
-    if (label.name == "job")
+    if (label.name == "service_name")
     {
       ASSERT_EQ(label.value, "test_service");
       checked_label_num++;
     }
-    else if (label.name == "instance")
+    else if (label.name == "service_instance_id")
     {
       ASSERT_EQ(label.value, "localhost:8000");
       checked_label_num++;
@@ -224,37 +197,20 @@ TEST(PrometheusExporterUtils, TranslateToPrometheusHistogramNormal)
 
   auto metric              = translated[1];
   std::vector<double> vals = {3, 900.5, 4};
-  assert_basic(metric, "library_name", "description", prometheus_client::MetricType::Histogram, 3,
+  assert_basic(metric, "library_name", "description", prometheus_client::MetricType::Histogram, 1,
                vals);
   assert_histogram(metric, std::list<double>{10.1, 20.2, 30.2}, {200, 300, 400, 500});
 
   int checked_label_num = 0;
-  for (auto &label : metric.metric[0].label)
-  {
-    if (label.name == "job")
-    {
-      // job label should be ignored when service.name exist
-      ASSERT_EQ(label.value, "unknown_service");
-      checked_label_num++;
-    }
-    else if (label.name == "instance")
-    {
-      ASSERT_EQ(label.value, "localhost:8001");
-      checked_label_num++;
-    }
-  }
-  ASSERT_EQ(checked_label_num, 2);
-
-  checked_label_num = 0;
   for (auto &label : translated[0].metric[0].label)
   {
-    if (label.name == "job")
+    if (label.name == "service_name")
     {
-      // job label should be ignored when service.name exist
+      // default service name is "unknown_service"
       ASSERT_EQ(label.value, "unknown_service");
       checked_label_num++;
     }
-    else if (label.name == "instance")
+    else if (label.name == "service_instance_id")
     {
       ASSERT_EQ(label.value, "localhost:8001");
       checked_label_num++;

From d0f15f2754517cf13b85bd8233ee3905f0c2e901 Mon Sep 17 00:00:00 2001
From: WenTao Ou <admin@owent.net>
Date: Fri, 29 Sep 2023 16:53:47 +0800
Subject: [PATCH 20/25] Remove unused variables.

Signed-off-by: WenTao Ou <admin@owent.net>
---
 exporters/prometheus/src/exporter_utils.cc | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 4e5b75707a..a54fb3e429 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -31,9 +31,6 @@ namespace metrics
 namespace
 {
 
-static constexpr const char *kPrometheusInstance = "instance";
-static constexpr const char *kPrometheusJob      = "job";
-
 /**
  * Sanitize the given metric name by replacing invalid characters with _,
  * ensuring that multiple consecutive _ characters are collapsed to a single _.

From bb62f0a5c6b7d88a24ebc4d1c0f33f9b82998aed Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sun, 1 Oct 2023 21:35:06 +0800
Subject: [PATCH 21/25] Populate target_info with every scrape

Signed-off-by: owent <admin@owent.net>
---
 exporters/prometheus/src/collector.cc | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/exporters/prometheus/src/collector.cc b/exporters/prometheus/src/collector.cc
index b066f3eb7b..f0937b6f4d 100644
--- a/exporters/prometheus/src/collector.cc
+++ b/exporters/prometheus/src/collector.cc
@@ -39,16 +39,8 @@ std::vector<prometheus_client::MetricFamily> PrometheusCollector::Collect() cons
   collection_lock_.lock();
 
   std::vector<prometheus_client::MetricFamily> result;
-
-  // If populate_target_info_ is true, populate target_info once.
-  bool populate_target_info = false;
-  if (populate_target_info_)
-  {
-    populate_target_info = true;
-
-    const_cast<PrometheusCollector *>(this)->populate_target_info_ = false;
-  }
-
+  
+  bool populate_target_info = populate_target_info_;
   reader_->Collect([&result, populate_target_info](sdk::metrics::ResourceMetrics &metric_data) {
     auto prometheus_metric_data =
         PrometheusExporterUtils::TranslateToPrometheus(metric_data, populate_target_info);

From db783e20f09e2219e5a61a66d1cc5c685216fa67 Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Sun, 1 Oct 2023 21:47:42 +0800
Subject: [PATCH 22/25] Fix style

Signed-off-by: owent <admin@owent.net>
---
 exporters/prometheus/src/collector.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exporters/prometheus/src/collector.cc b/exporters/prometheus/src/collector.cc
index f0937b6f4d..9082f49f6f 100644
--- a/exporters/prometheus/src/collector.cc
+++ b/exporters/prometheus/src/collector.cc
@@ -39,7 +39,7 @@ std::vector<prometheus_client::MetricFamily> PrometheusCollector::Collect() cons
   collection_lock_.lock();
 
   std::vector<prometheus_client::MetricFamily> result;
-  
+
   bool populate_target_info = populate_target_info_;
   reader_->Collect([&result, populate_target_info](sdk::metrics::ResourceMetrics &metric_data) {
     auto prometheus_metric_data =

From dd737e3cf2a6b92577dfa8fe85fd265d8dcf7c9f Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Tue, 3 Oct 2023 22:42:29 +0800
Subject: [PATCH 23/25] Fix some legacy issues to remove `job` and `instance`
 labels.

Signed-off-by: owent <admin@owent.net>
---
 exporters/prometheus/src/collector.cc      | 5 ++---
 exporters/prometheus/src/exporter_utils.cc | 2 +-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/exporters/prometheus/src/collector.cc b/exporters/prometheus/src/collector.cc
index 9082f49f6f..33b9a9b8c8 100644
--- a/exporters/prometheus/src/collector.cc
+++ b/exporters/prometheus/src/collector.cc
@@ -40,10 +40,9 @@ std::vector<prometheus_client::MetricFamily> PrometheusCollector::Collect() cons
 
   std::vector<prometheus_client::MetricFamily> result;
 
-  bool populate_target_info = populate_target_info_;
-  reader_->Collect([&result, populate_target_info](sdk::metrics::ResourceMetrics &metric_data) {
+  reader_->Collect([&result, this](sdk::metrics::ResourceMetrics &metric_data) {
     auto prometheus_metric_data =
-        PrometheusExporterUtils::TranslateToPrometheus(metric_data, populate_target_info);
+        PrometheusExporterUtils::TranslateToPrometheus(metric_data, this->populate_target_info_);
     for (auto &data : prometheus_metric_data)
       result.emplace_back(data);
     return true;
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 5b834f8176..0ecabc3983 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -379,7 +379,7 @@ void PrometheusExporterUtils::SetMetricBasic(
   // Note that attribute keys are sorted, but sanitized keys can be out-of-order.
   // We could sort the sanitized keys again, but this seems too expensive to do
   // in this hot code path. Instead, we ignore out-of-order keys and emit a warning.
-  metric.label.reserve(labels.size() + 2);
+  metric.label.reserve(labels.size());
   std::string previous_key;
   for (auto const &label : labels)
   {

From b6ca2f2b22c36e0fbd437c7b3d596cffad2286bf Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Tue, 3 Oct 2023 23:02:02 +0800
Subject: [PATCH 24/25] Add scope for target-info

Signed-off-by: owent <admin@owent.net>
---
 .../exporters/prometheus/exporter_utils.h            |  1 +
 exporters/prometheus/src/exporter_utils.cc           | 12 +++++++-----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index c0cb85c62f..96c7ac8826 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -58,6 +58,7 @@ class PrometheusExporterUtils
    * Add a target_info metric to collect resource attributes
    */
   static void SetTarget(const sdk::metrics::ResourceMetrics &data,
+                        const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope,
                         std::vector<::prometheus::MetricFamily> *output);
 
   /**
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 0ecabc3983..49ece800a5 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -134,9 +134,9 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
   output.reserve(reserve_size);
 
   // Append target_info as the first metric
-  if (populate_target_info)
+  if (populate_target_info && !data.scope_metric_data_.empty())
   {
-    SetTarget(data, &output);
+    SetTarget(data, (*data.scope_metric_data_.begin()).scope_, &output);
   }
 
   for (const auto &instrumentation_info : data.scope_metric_data_)
@@ -293,8 +293,10 @@ prometheus_client::MetricType PrometheusExporterUtils::TranslateType(
   }
 }
 
-void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &data,
-                                        std::vector<::prometheus::MetricFamily> *output)
+void PrometheusExporterUtils::SetTarget(
+    const sdk::metrics::ResourceMetrics &data,
+    const opentelemetry::sdk::instrumentationscope::InstrumentationScope *scope,
+    std::vector<::prometheus::MetricFamily> *output)
 {
   if (output == nullptr || data.resource_ == nullptr)
   {
@@ -311,7 +313,7 @@ void PrometheusExporterUtils::SetTarget(const sdk::metrics::ResourceMetrics &dat
   metric.info.value                       = 1.0;
 
   metric_sdk::PointAttributes empty_attributes;
-  SetMetricBasic(metric, empty_attributes, data.resource_);
+  SetMetricBasic(metric, empty_attributes, scope, data.resource_);
 
   for (auto &label : data.resource_->GetAttributes())
   {

From 0149d5ccdfe3c83812e2edaaa6350c5463da8c4b Mon Sep 17 00:00:00 2001
From: owent <admin@owent.net>
Date: Tue, 3 Oct 2023 23:27:38 +0800
Subject: [PATCH 25/25] Restore `+2` when reserve space for vector.

Signed-off-by: owent <admin@owent.net>
---
 exporters/prometheus/src/exporter_utils.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 49ece800a5..42fafc6336 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -381,7 +381,7 @@ void PrometheusExporterUtils::SetMetricBasic(
   // Note that attribute keys are sorted, but sanitized keys can be out-of-order.
   // We could sort the sanitized keys again, but this seems too expensive to do
   // in this hot code path. Instead, we ignore out-of-order keys and emit a warning.
-  metric.label.reserve(labels.size());
+  metric.label.reserve(labels.size() + 2);
   std::string previous_key;
   for (auto const &label : labels)
   {